Engine Control & Management

System
 BYD S6, S6A, S6K Service Manual

Engine Control & Management System

Contents

Section 1 Engine electronic control system-1........................................................................ 1

1. Summary.......................................................................................................... 1
2. Multi-point fuel injection system map ............................................................... 3
3. Inspection and Adjustion .................................................................................. 5
4. Diagnostic Trouble Code Procedures ............................................................ 31
5. Ignition System ............................................................................................ 113
6. Charging system .......................................................................................... 117
7. Starting system ............................................................................................ 129
Section 2 Engine electronic control system-2.................................................................... 140
1. Troubleshooting Procedures ........................................................................ 140
2. Ignition System ............................................................................................ 183
3. Charging system .......................................................................................... 187
4 Starting System............................................................................................ 199
Section 3 BYD TB10 Engine Management System Service Manual.................................. 208
1. EFI Service Notice ....................................................................................... 208
2. TB10 System Overview ............................................................................... 211
3. TB10 System Component Structure, Principle and Troubleshooting ........... 221
4. Diagnostic Procedures of Servicing TB10 System as per DTC ................... 261
5. Diagnostic Procedures of Servicing TB10 System as per Symptoms of
Malfunction .................................................................................................. 290
6. Self-learning and Operating Instructions...................................................... 303
7. Usage of Electric Diagnostic Tester ............................................................. 305
8. Appendix ...................................................................................................... 312
Section 4 BYD 483QA M7 Engine Management System..................................................... 322
1. Maintenance Notice of Electronic Fuel Injection System ............................. 323
2. M7 System Introduction ............................................................................... 328
3. Parts Structure, Principle and Fault Analysis of M7 System ........................ 339
4. Maintenance and Diagnosis procedure of M7 according to the DTC .......... 381
5. Diagnostic procedure of M7 system according to fault phenomenon .......... 401
6. M7 system Diagnosis Instrument Using Direction ....................................... 412
7. Accessory .................................................................................................... 428

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 BYD S6, S6A, S6K Service Manual

Section 5 488QB ME7 Management System........................................................................ 432

1. Electronic fuel injection system notice ......................................................... 434
2. ME7 system introduction.............................................................................. 438
3. Structure, principle and fault analysis for ME7 system parts ....................... 447
4. ME7 system checks diagnosis flow according to fault code. ....................... 483
5. ME7 system checks diagnosis flow according to fault phenomenon ........... 484
6. ME7system diagnosis tester function requirement ...................................... 497
7. Accessories:................................................................................................. 498

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 BYD S6, S6A, S6K Service Manual

Section 1 Engine electronic control system-1

1. Summary
The system is electronic control multi-point sequence fuel injection, the engine electronic unit
(called computer ECU) measure all parameters of engine by all kinds of sensor which are in-
stalled on different position, make the engine get the best concentration mix gas under all kinds of
condition by controlling fuel injector to precisely control fuel injecting amount according to set con-
trol program in computer in advance. In addition, the electronic control fuel injection system can
carry out the functions such as start enhance, warm up engine enhance, acceleration enhance,
full load enhance, deceleration dilution, compulsively idle fuel cut-off and automatic idle speed
control by the program which is in computer and meet the request that engine special condition
need mix gas to make engine get better fuel economy and emission, meanwhile improve vehicle
performance. And the ECU also has several kinds of trouble diagnostic mode to simple the work
to find out trouble.

Fuel injection control

ECU control fuel injector drive time and injection timing to make the engine get the best concen-
tration mix gas. Intake of every cylinder is equipped with a fuel injector, the fuel pump send fuel
to fuel distribution pipe; fuel pressure adjuster makes fuel pressure stable and injector make the
fuel into air passage of every cylinder. In the engine every work circle ( crankshaft rotate for both
circles), every cylinder injects fuel one time ( the sequence is 1-3-4-2), the way is called sequence
injection. When engine runs under cooling state or high load, to keep better performance ECU
carry out open-loop control to supply stronger mix gas; When engine work normally (medium-
light load), ECU carry out closed-loop control to get the best air/fuel ratio and make the three-way
catalyze converter get to the best purificatory efficiency by signal which is fed back by oxygen
sensor.

Throttle opening control

Throttle system is electronic control, engine ECU measures acceleration pedal journey by accel-
eration pedal sensor and control servo motor action on the throttle to get to drive condition and
make throttle target opening get to set value in advance.

Idle speed control

Control throttle bypass air amount according to idle condition and engine load change under idle
to keep best idle speed. ECU drives idle to control servo system according to engine coolant tem-
perature and A/C load to make the engine run under set target idle speed. In addition, when en-
gine runs under idle, open or close A/C switch, then idle control servo system will adjust bypass
air amount according to engine load condition to avoid idle unstable.

Ignition timing control

Electronic control unit control the open and close of power transistor to control the conduction of
ignition coil primary current. The purpose of ignition timing control is to obtain the best ignition
time to meet engine change condition request. ECU determines the ignition time according to
engine speed, intake amount, intake temperature, engine cooling water temperature and air pres-
sure.

Self-diagnosis operation

(1) When finding out that a sensor and actuator is abnormal, engine trouble lamp will be on to
remind driver.

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 BYD S6, S6A, S6K Service Manual

(2) When finding out that a sensor and actuator is abnormal, the DTC which is related with trou-
ble situation will be output.

(3) The RAM data in ECU which has the relationship with sensor and actuator will be read by
MUT-III.

Other control operation

(1) Fuel pump control

When engine starts and runs, fuel pump relay opens to pass current to fuel pump.
(2) A/C relay control

Open or close A/C compressor.

(3) Oil adjusting valve control

To keep consistent of cylinder work and engine speed, ECU impacts closed-loop control by oil
control valve; Under the control, oil control valve turns on different valve angles according to dif-
ferent working conditions to make the amount of oil different which goes into camshaft transfer
intake rocker arm shaft. It achieves that intake and exhaust valve open and closed time adjust in
time with engine speed and ensure that engine works in best condition.
(4) Fan motor control

Engine coolant temperature and speed signal control the rotate of radiator and condenser fan.
(5) Alternator output current control

The purpose is to avoiding alternator output current increasing suddenly and idle decreasing any-
time. For example, when opening front headlamp, engine load is increased, and alternator output
current control will input ECU current signal.ECU will control speed to compensate the changes
after detecting this signal.
(6) Purification solenoid control

Purification emission control system can prevent fuel vapor which is produced by fuel tank to en-
ter into air. Fuel vapor in fuel tank is temporarily stored in charcoal canister by pressure control
valve and ventilation hose. When vehicle drives, the fuel vapor which is stored in charcoal canis-
ter enter into inlet manifold and be sent into combustion chamber by purification control solenoid
and purifier; when engine water temperature is lower or intake is smaller ( for example, idle),
ECU closes purification solenoid to prevent fuel vapor to enter into inlet manifold. This can make
sure drive performance under engine cooling state or low load and make exhaust emission stable.
(7) EGR solenoid control

EGR low the NOx emission amount ; When air and fuel mixture temperature is high, combustion
chamber produces a lot of NOx. So EGR recycle to make part of exhaust sent into inlet manifold
from outlet on cylinder head to decrease mix gas temperature and further low NOx amount. EGR
valve control exhaust flow not to low drive performance.

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 BYD S6, S6A, S6K Service Manual

2. Multi-point fuel injection system map

• 1. 1,4 cylinder Power voltage • 1. Oil adjusting Engine control

oxygen sensor valve relay
Engine
• 2 . C y l i n d e r Ignition switch- • 2. Throttle servo
oxygen sensor IG ECU system Fuel pump relay
• 3. Camshaft • 3. Fuel injector
position sensor Ignition switch- Air pres- • 4. EGR manifold
A/C compressor
• 4. Water tem-
IG sure relay
• 5. Purification
perature sen-
A/C switch sensor control solenoid Throttle servo
sor
relay
• 5. Crankshaft A/C load signal
angle sensor Ignition coil
• 6. Knock sen- A / C p r e s s u r e
sor sensor Fan control
• 7. Throttle po-
sition sensor Power redirector Trouble warning
(host) switch lamp
• 8. Throttle po-
sition sensor Ge n e ra to r FR Control relay
(sub) end
Diagnostic sig-
• 9. Intake tem-
Acceleration nal
perature sen-
sor pedal position
switch Generator G end
• 10. Airflow
sensor
Acceleration Tachometer
pedal position 1, 4, cynlinder
sensor (host, oxygen sensor
sub)

Speed sensor
M/T

Anti-manual
shift switch A/T

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Manifold absolute pressure sensor

(without oil return system)
7 Throttle position sensor (host)
8 Throttle position sensor (sub)

2 Throtle servo system 9 Intake temperature sensor

Cylinder oxygen sensor 3 Camshaft position sensor 10 Airflow sensor

1 Oil adjusting valve

Air

Fuel pressure
adjuser
From fuel pump

To fuel tank 3 Fuel injector

Filter
4 ECR solenoid

4 Water temperature sensor

Accelerant
converter
5 Crankshaft angle sensor 5 Purification control solenoid
6 Knock sensor

Rear oxygen Sensor

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3. Inspection and Adjustion

3.1 Basic specification

Items Specification
Throttle hole diameter mm 60
Throttle Throttle position sensor Hall type
Idle control servo mechanism DC motor model
Engine electronic unit <M/T> ECU model
Engine electronic unit <A/T> ECU model
Airflow sensor Thermo sensitive type
Air pressure sensor Semiconductor type
Intake temperature sensor Thermo sensitive-resistance type
Water temperature sensor Thermo sensitive-resistance type
Oxygen sensor Zirconia type
Accelerate pedal position sensor Slide resistance type
Sensor
Speed sensor <M/T> Magneto resistance type
Anti-manual shift switch <A/T> Contact switch type
Camshaft position sensor Magneto resistance type
Crankshaft corner sensor Magneto resistance type
Knock sensor Piezoelectricity type
power turning hydraulic switch Semiconductor type
Engine control relay type Contact switch type
Fuel pump relay Contact switch type
The type and amount of fuel injec-
Electromagnetic type, four
tor

Actuator Injector VIN

Throttle control relay Contact switch
Oil pressure adjusting valve Load-recycled solenoid
EGR control solenoid Stepping motor
Crankshaft case ventilation valve Load-recycled solenoid

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3.2 Repair specification

Items Specification
-20°C 13 - 17
0°C 5.3 - 6.7
20°C 2.3 - 3.0
Intake temperature sensor resistance kΩ
40°C 1.0 - 1.5
60°C 0.56 - 0.76
80°C 0.30 - 0.45
-20°C 14 - 17
0°C 5.1 - 6.5
20°C 2.1 - 2.7
Water temperature sensor resistance kΩ
40°C 0.9 - 1.3
60°C 0.48 - 0.68
80°C 0.26 - 0.36
Oxygen sensor output voltage ( running) V 0.6 - 1.0
Oxygen sensor heater resistance (at the 20°C) Ω 11 - 18
Vacuum hose taken off In basic idle about 324 - 334
Fuel pressure kPa
Vacuum hos collected In basic idle about 248
Fuel injector coil resistance (at the 20°C) Ω 10.5 - 13.5
Throttle control servo coil resistance (at the 20°C) Ω 0.3 - 80
Oil control valve (at the 20°C) Ω 6.9 - 7.9

3.3 Sealant

Items Sealant Remark

Used for 3M screw fastened, product NO.4171
Coolant temperature sensor screw Dry
or the same glue

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3.4 Special tool

Tool Serial NO. Tool Name Usage

MB991955 MUT-III and accessory Read DTC

A: MB991824 A: MUT-III diagnosis tester Check MPI system
B: MB991827 B: MUT-III USB interface wire Measure fuel pressure
C: MB991910 C: MUT-III main connective wire
NOTICE
A (used in the vehicle with com-
D: MB991911
munication interface) The vehicle with commu-
E: MB991825 nication interface can use
D: MUT-III main connective wire
MUT-III main connective
F: MB991826 B(used in the vehicle without
wire A to send a simulate
communication interface)
speed signal. the MUT-III
E: MUT-III test connector main connective wire B
hasn’t the function.
F: MUT-III trigger wire

• Measure voltage when

MB991709 Test wire testing trouble
• Test with oscillograph
• Measure voltage when
MB991316 Test wire (4pins, square) testing trouble
• Test oxygen sensor
• Measure voltage when
testing trouble
MD998464 Test wire (4 pins, square)
• Te s t o x y g e n s e n s o r
(Rear)
• Measure voltage when
testing trouble
MB991658 Test wire
• Test with oscillograph
• Test dataflow

MD998709 Connective hose

MD998742 Hose interface Measure fuel pressure

Fuel pressure measure ele-

MB991637
ments

Fuel pressure measure ele-

MB991981
ments

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Tool Serial NO. Tool Name Usage

MD998706 Injector measure elements

MB991607 Injector measure wire

Check atomizing state of in-
jector
MD998741 Injector measure connector

MB991976 Injector measure fixed elements

3.5 Trouble Diagnosis & Repair Flow

Diagnosis specification

NOTICE
Within diagnosis, if the ignition switch is open, but connector is disconnected, a DTC re-
lated with other systems is produced. After diagnosis, record all the DTC and erase them.

How to read DTC

NOTICE
You must first close ignition switch, and
then connect or disconnect connective
wire of diagnostic tester.

Connect MUT-III diagnostic tester to diagnos-

tic connector with 16 pins and read DTC.

NOTICE
Please refer to MUT-III operation specifi-
cation to use MUT-III.

1. Make sure the ignition switch is on the

“LOCK” (OFF).

2. Open computer which is connected.

3. Connect diagnostic tester with computer

by MB991827, MUT-III USB wire

4. Connect MUT-III main connective wire A

to apparatus communication interface.

5. Connect MUT-III main connective wire A

AC310120AB
to vehicle diagnostic connector.

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6. Open diagnostic tester power switch.

NOTICE
After opening diagnostic tester power,
the green indicator will be on.

7. Open the MUT-III in the computer, and

open ignition switch.

8. Read DTC

9. Close ignition switch and as the contrary

connective sequence disassemble diag-
nostic tester.

Erase DTC

NOTICE
You must first close ignition switch, and
then connect or disconnect diagnostic
tester connective wire.

Connect MUT-III to diagnostic connector, and

erase DTC. It is similar with reading DTC.

Check input signal (with MUT-III)

1. Connect MUT-III to diagnostic connector,

and then erase DTC.

Diagnostic tester carry out ON/OFF ac-

tion of every switch one by one, if every
buzzer sound one time when open/close
switch, that shows the switch loop is nor-
mal.

AC310120AB

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Check input signal (with voltage meter)

Use the special tool (MB991529) of DTC

checking wire to connect voltage meter
and diagnostic connector 9# and ground
(4# or 5# ), if finger of voltage meter
sway one time in every switch action,
shows the switch loop is normal.

AC310121AB

3.5.1 Initialization program of multi-point fuel injection engine

Initialization program

1. Turn ignition switch to “LOCK” (OFF) position, connect MUT-III diagnostic tester to diagnostic
connector.

2. Choose the initializing learn on screen.

Repair Items
*1, *2
Replace engine assembly All components
- *3 Related with misfire
*2
The learn on replacing injector Learn air/fuel ratio
*2
The learn on replacing throttle body Related with idle
The learn on replacing knock sensor Learn knock

NOTICE
*1
: be suitable for learn on automatic transmission

NOTICE
*2
: after learn, carry out the learn on engine idle

NOTICE
*3
: MUT-III only is displaying item of apparatus, and don’t use

3.5.2 Idle learn program of MPI engine

Purpose

After replacing engine electronic control unit or initializing learn, idle may be unstable, so carry out
the learn on engine idle.

Learn program

1. Start engine until its temperature get to over 80°C.

2. If the engine runs always, it is no necessary to warm up engine.

3. Close ignition switch.

4. Wait for over 10 seconds, anew start engine.

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5. Engine run for 10 minutes under idle, the idle learn is finished.

The premise of idle learn:

1) Transmission case: N gear

2) Close all lamp, fan, A/C and other load

3) Water temperature is over 80°C.

3.5.3 Diagnostic function

Engine warning lamp (engine checking

lamp)

If the following abnormal situation which is re-

lated with MPI happens, engine lamp will be
on. when engine run, If the pump still is on,
check DTC output.

Checking items on engine warning lamp

Engine-ECU
Accelerate pedal position sensor (main)
Accelerate pedal position sensor (sub)
Airflow sensor
Alternator
Air pressure sensor
Camshaft position sensor
Crankshaft corner sensor
Cylinder misfire
Knock sensor
Electronic throttle system
Water temperature sensor
Fuel injector
Intake temperature sensor
Oxygen sensor
Throttle position sensor (main)
Throttle position sensor (sub)
Speed sensor <M/T>

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Please refer to above method on reading

and erasing DTC

Diagnostic mode 2

1. Turn the diagnostic mode of electronic

control unit to diagnostic mode 2 by
MUT-III diagnostic tester.

2. Make road test.

3. After reading DTC repair it.

4. First Close, then open ignition switch.

NOTICE
Close ignition switch, engine electronic
control unit will be changed from diag-
nostic mode 2 to mode 1.

5. Erase DTC.

Check with MUT-III dataflow and actuator

1. Check with dataflow and actuator. If the

abnormal symptom exists, check and
repair chassis electricity spare wire and
elements.

2. After repairing, once more check with

MUT-III, check whether the abnormal in-
put and output is normal after repairing.

3. Erase DTC stored in memorizer

Remove MUT-III, start engine and make

road test to make sure whether the trou-
ble is solved.

3.6 Reference Table on Trouble Defending Function

When testing main sensor trouble, control vehicle with set control logical circuit which is used to
keep drive safe condition.

Trouble item Control content when trouble happens

Read basic injector drive timing and ignition timing from set diagram
Airflow sensor with throttle position sensor signal and engine speed sensor (crank-
shaft corner sensor signal)
Intake temperature sensor Control at the 25°C intake temperature.
Air pressure sensor Control at the 101kPa air pressure

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Trouble item Control content when trouble happens

• Control throttle position by throttle position sensor (sub)

• Send accelerate pedal journey, it accounts a half of standard

open angel.
• Pretend work that is controlled by engine feedback.
Throttle position sensor (main)
• Automatic cut-off fuel when engine speed exceeding 3, 000 r/
min.
• If throttle position sensor (sub) has trouble, restrain engine
output by stopping electronic control system.

• Control throttle position by throttle position sensor (main)

• Transfer accelerate pedal journey, open it to half of standard

open angle
• Pretend to run which is controlled by engine feedback.
Throttle position sensor (sub)
• Automatic cut-off fuel when engine speed exceeding 3, 000 r/
min.
• If throttle position sensor (main) has trouble, can restrain engine
output by stopping electronic control throttle system.

• Detect accelerate pedal journey by accelerate pedal position

sensor (sub), open it to about half of standard open angle.
Accelerate pedal position sensor • Automatic cut-off fuel when engine speed exceeding 3, 000 r/
(main) min.
• If accelerate pedal position sensor (sub) has trouble, restrain
engine output by stopping electronic control throttle system.

• Detect accelerate pedal journey by accelerate pedal position

sensor (sub), open it to about half of standard open angle.
Acelerate pedal position sensor • Automatic cut-off fuel when engine speed exceeding 3, 000 r/
(sub) min.
• If accelerate pedal position sensor (sub) has trouble, restrain
engine output by stopping electronic control throttle system.
Engine coolant temperature sensor Coolant temperature control as 80°C.
Rulelessly inject fuel as the sequence 1-3-4-2. but after turning igni-
Camshaft position sensor tion switch to ON position, doesn’t check the first cylinder top dead
center.
Oxygen sensor Closed-loop air/fuel ratio control is stopped.
Control ignition timing conversion from high octane fuel and standard
Knock sensor
octane fuel.
Ignition coil, power transistor Cut off fuel to cylinder when abnormal ignition.
Alternator FR terminal The output control of alternate isn’t according to powerload.
Misfire Detect the misfire, close related cylinder.
Restrain engine output by stopping electronical control system.
Throttle position feedback
Prevent to run which is controlled by engine feedback.

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Trouble item Control content when trouble happens

• Restrain engine output by stopping electronical control system
Throttle servo mechanism
• Prevent to run which is controlled by engine feedback.

• Restrain engine output by stopping electronical control system

Engine electronic control unit
• Prevent to run which is controlled by engine feedback.

• Transmit accelerate pedal journey, open to half of standard open

angle.
The communication between power
control module and system integrate • Prevent to run which is controlled by engine feedback
circuit
• Automatic cut off fuel when engine speed exceeding 3, 000 r/
min.
Restrain engine output by stopping electronical control system
Monitor intake
Prevent to run which is controlled by engine feedback.
Can’t switch to high speed camshaft.
Oil control valve
Automatic cut off fuel when engine speed exceeding 5, 000 r/min.

3.7 DTC Table

DTC DTC DIAGNOSIS ITEMS

P0030 FRONT OXYGEN SENSOR HEATING CONTROL CIRCUIT MALFUNCTION
P0031 FRONT OXYGEN SENSOR HEATING CONTROL CIRCUIT VOLTAGE OVER LOW
P0032 FRONT OXYGEN SENSOR HEATING CONTROL CIRCUIT VOLTAGE OVER HIGH
P0036 REAR OXYGEN SENSOR HEATING CONTROL CIRCUIT MALFUNCTION
P0037 REAR OXYGEN SENSOR HEATING CONTROL CIRCUIT VOLTAGE OVER LOW
P0038 REAR OXYGEN SENSOR HEATING CONTROL CIRCUIT VOLTAGE OVER HIGH
P0053 FRONT OXYGEN SENSOR HEATING INTERNAL RESISTANCE ABNORMAL
P0054 REAR OXYGEN SENSOR HEATING INTERNAL RESISTANCE ABNORMAL
P0105 BOOST SENSOR SIGNAL NO FLUCTUATION
P0106 BOOST SENSOR ABNORMAL
P0107 BOOST SENSOR GROUNDING SHORT CIRCUIT
P0108 BOOST SENSOR ELECTRICITY SHORT CIRCUIT
P0112 BOOST SENSOR SIGNAL CIRCUIT VOLTAGE OVER LOW
P0113 BOOST SENSOR SIGNAL CIRCUIT VOLTAGE OVER HIGH
P0117 COOLANT SENSOR CIRCUIT VOLTAGE OVER LOW
P0118 COOLANT SENSOR CIRCUIT VOLTAGE OVER HIGH
P0122 ELECTRONIC THROTTLE POSITION SENSOR 1 SIGNAL CIRCUIT VOLTAGE OVER LOW
ELECTRONIC THROTTLE POSITION SENSOR 1 SIGNAL CIRCUIT VOLTAGE OVER
P0123
HIGH
P0130 FRONT OXYGEN SENSOR SIGNAL ABNORMAL
P0131 FRONT OXYGEN SENSOR SIGNAL CIRCUIT VOLTAGE OVER LOW
P0132 FRONT OXYGEN SENSOR SIGNAL CIRCUIT VOLTAGE OVER HIGH

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DTC DTC DIAGNOSIS ITEMS

P0133 FRONT OXYGEN SENSOR AGEING
P0134 FRONT OXYGEN SENSOR CIRCUIT MALFUNCTION
P0136 REAR OXYGEN SENSOR SIGNAL ABNORMAL
P0137 REAR OXYGEN SENSOR SIGNAL VOLTAGE OVER LOW
P0138 REAR OXYGEN SENSOR SIGNAL VOLTAGE OVER HIGH
P0140 REAR OXYGEN SENSOR CIRCUIT MALFUNCTION
INSERTING COIL DECTECTING AIR-FUEL RATIO CLOSED-LOOP CONTROL SELF-
P0170
LEARNING ABNORMAL
INSERTING COIL DETECTING AIR-FUEL RATIO CLOSED-LOOP CONTROL SELF-
P0171
LEARNING MORE
INSERTING COIL DETECTING AIR-FUEL RATIO CLOSED-LOOP CONTROL SELF-
P0172
LEARNING LESS
P0201 IST CYLINDER FUEL INJECTOR OPEN CIRCUIT
P0202 2ND CYLINDER FUEL INJECTOR OPEN CIRCUIT
P0203 3RD CYLINDER FUEL INJECTOR OPEN CIRCUIT
P0204 4TH CYLINDER FUEL INJECTOR OPEN CIRCUIT
P0261 IST CYLINDER FUEL INJECTOR SHORT CIRCUIT TO GROUND
P0262 IST CYLINDER FUEL INJECTOR SHORT CIRCUIT TO POWER SUPPLY
P0264 2ND CYLINDER FUEL INJECTOR SHORT CIRCUIT TO GROUND
P0265 2ND CYLINDER FUEL INJECTOR SHORT CIRCUIT TO POWER SUPPLY
P0267 3RD CYLINDER FUEL INJECTOR SHORT CIRCUIT TO GROUND
P0268 3RD CYLINDER FUEL INJECTOR SHORT CIRCUIT TO POWER SUPPLY
P0270 4TH CYLINDER FUEL INJECTOR SHORT CIRCUIT TO GROUND
P0271 4TH CYLINDER FUEL INJECTOR SHORT CIRCUIT TO POWER SUPPLY
P0300 SOME CYLINDERS CATCH FIRE
P0301 IST CYLINDER MISFIRE
P0302 2ND CYLINDER MISFIRE
P0303 3RD CYLINDER MISFIRE
P0304 4TH CYLINDER MISFIR
P0321 CRANKSHAFT TOP DEAD CENTER GEAR SIGNAL ABNORMAL
P0322 SPEED SENSOR SIGNAL MALFUNCTION
P0327 KNOCK SENSOR SIGNAL CIRCUIT VOLTAGE OVER LOW
P0328 KNOCK SENSOR SIGNAL CIRCUIT VOLTAGE OVER HIGH
P0340 CRANKSHAFT POSITION SENSOR MOUNTING POSITION IMPROPERLY
P0341 CRANKSHAFT POSITION SENSOR ABNORMAL
P0342 CRANKSHAFT POSITION SENSOR SIGNAL CIRCUIT SHORT CIRCUIT TO GROUND
CRANKSHAFT POSITION SENSOR SIGNAL CIRCUIT SHORT CIRCUIT TO POWER SUP-
P0343
PLY
P0420 3-WAY CATALYTIC CONVERTER AGING
P0444 CANISTER PURGE VALVE OPEN CIRCUIT

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DTC DTC DIAGNOSIS ITEMS

P0458 CANISTER PURGE VALVE CIRCUIT VOLTAGE OVER LOW
P0459 CANISTER PURGE VALVE CIRCUIT VOLTAGE OVER HIGH
P0480 COOLING FAN RELAY OPEN CIRCUIT(LOW SPEED)
P0481 COOLING FAN RELAY OPEN CIRCUIT(HIGH SPEED)
P0501 VEHICLE SPEED SENSOR MALFUNCTION
P0506 IDLE SPPED LOWER THAN TARGET SPEED
P0507 IDLE SPPED HIGHER THAN TARGET SPEED
P0508 STEPPING MOTOR DRIVE PIN SHORT CIRCUIT TO GROUND
P0509 STEPPING MOTOR DRIVE PIN SHORT CIRCUIT TO GROUND
P0511 STEPPING MOTOR DRIVE CIRCUIT MALFUNCTION
P0560 STORAGE BATTERY VOLTAGE SIGNAL ABNORMAL
P0562 STORAGE BATTERY VOLTAGE OVER LOW
P0563 STORAGE BATTERY VOLTAGE OVER HIGH
P0602 ECU CODING MALFUNCTION
P0627 FUEL PUMP REALY OPEN CIRCUIT
P0628 FUEL PUMP RELAY CIRCUIT VOLTAGE OVER LOW
P0629 FUEL PUMP RELAY CIRCUIT VOLTAGE OVER HIGH
P0660 VARIABLE AIR INLET CONTROL VALVE OPEN CIRCUIT
P0661 VARIABLE AIR INLET CONTROL VALVE SHORT CIRCUIT TO GROUND
P0662 VARIABLE AIR INLET CONTROL VALVE SHORT CIRCUIT TO POWER SUPPLY
P0691 COOLING FAN RELAY CIRCUIT VOLTAGE OVER LOW(LOW SPEED)
P0692 COOLING FAN RELAY CIRCUIT VOLTAGE OVER HIGH(LOW SPEED)
P0694 COOLING FAN RELAY CIRCUIT VOLTAGE OVER HIGH(HIGH SPEED)
P0A0F ENGINE BLOCKING ROTATING OR STARTER MALFUNCTION
AIR-FUEL RATIO CLOSED-LOOP SELF-LEARNING VALVE OVER UPPER LIMIT(MIDDLE
P2177
LOAD)
AIR-FUEL RATIO CLOSED-LOOP SELF-LEARNING VALVE OVER LOWER LIMIT(MIDDLE
P2178
LOAD)
AIR-FUEL RATIO CLOSED-LOOP SELF-LEARNING VALVE OVER UPPER LIMIT(LOW
P2187
LOAD)
AIR-FUEL RATIO CLOSED-LOOP SELF-LEARNING VALVE OVER LOWER LIMIT(LOW
P2188
LOAD)
P2195 FRONT OXYGEN SENSOR AGING
P2196 FRONT OXYGEN SENSOR AGING

NOTICE
• Before replacing engine electronic unit, make sure to check if the terminal is short
circuit or open circuit.
• Before replacing engine electronic unit, make sure to check if the grounding end is
fine.

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 BYD S6, S6A, S6K Service Manual

DTC DTC DIAGNOSIS ITEMS

P2270 REAR OXYGEN SENSOR AGING
P2271 REAR OXYGEN SENSOR AGING
U0001 CAN COMMUNICATE RELATED DIAGNOSIS
U0146 ECU AND GATEWAY LOSE COMMUNICATION
U0415 COMMUNICATING OF ECU AND ABS ABNORMAL
U0427 FUEL CUT OFF AFTER CRASH
U0447 SRS INFORMATION WRONG
P0645 A/C COMPRESSOR RELAY OPEN CIRCUIT(CLOSED)
P0646 A/C COMPRESSOR RELAY CIRCUIT VOLTAGE OVER LOW(CLOSED)
P0647 A/C COMPRESSOR RELAY CIRCUIT VOLTAGE OVER HIGH(CLOSED)
MALFUNCTION INDICATOR LAMP DRIVING STAGE SHORT CIRCUIT TO POWER
P0650
SUPPLY(CLOSED)
P1651 SVS LAMP DRIVING STAGE CIRCUIT MALFUNCTION(CLOSED)

3.8 Cleaning Throttle Body

1. Disassemble Intake Hose From Throttle body.

2. Disassemble throttle body assembly.

NOTICE
• Don’t directly point washing liquid at throttle.
• Make sure the washing liquid doesn’t enter into motor from bypass port and does’t
enter into sensor from shaft.

3. Sprinkle washing liquid to washing cloth.

4. Wipe dirt out of throttle with washing cloth.

5. Fix throttle body assembly.

6. Fix intake hose.

3.9 Checking Conduction of engine control relay

Triangle mark Test Standard

of relay box Voltage
terminal state
2-3 Non voltage Conduct
Non con-
Control relay Non voltage
duct

Side connector 1-4 voltage(connect

of device battery (+) to 3#
Conduct
terminal (-) and to
2# termianl)

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 BYD S6, S6A, S6K Service Manual

3.10 Checking conduction of throttle servo control relay

Triangle mark Test Standard

Voltage
of relay box terminal state
2-3 Non voltage Conduct
Non con-
Throttle valve Non voltage
servorelay duct
Side connector 1-4 voltage(connect
of device battery (+) to 3#
terminal (-) and to
2# terminal)

3.11 Checking intake temperature sensor

1. Disassemble wire harness connector of

airflow sensor.
Intake air
temperature 2. Measure the resistance between 1# ter-
sensor minal and 4 terminal
Standard value:

13 - 17 kΩ (at -20°C)
Device side connecto 5.3 - 6.7 kΩ (at 0°C)

2.3 - 3.0 kΩ (at 20°C)

1.0 - 1.5 kΩ (at 40°C)

0.56 - 0.76 kΩ (at 60°C)

0.30 - 0.45 kΩ (at 80°C)

3. Disassemble airflow sensor

Heat intake temperature sensor with electron-

ic hair dryer, and anew measure resistance.

Standard value

Temperature (°C) Resistance (kΩ)

Intake air High Low
temperature
sensor
4. If resistance deviate the standard value
or resistance doesn’t change, you should
replace airflow sensor assembly.
Fasten torque: 1.8 ± 0.6 N•m

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 BYD S6, S6A, S6K Service Manual

3.12 Checking engine water temperature sensor

NOTICE
Water When disassembly or assembly, don’t
temperatur makee the tool touch connector (pitch
sensor
part).

1. Disassemble engine water temperature

sensor
Side connector of device
2. Make the water temperature sensor sink
into hot water to check resistance.

Standard value:

14 - 17 kΩ (at -20°C)

5.1 - 6.5 kΩ (at 0°C)

2.1 - 2.7 kΩ (at 20°C)

0.9 - 1.3 kΩ (at 40°C)

0.48 - 0.68 kΩ (at 60°C)

0.26 - 0.36 kΩ (at 80°C)

3. If the offset of resistance is more than

standard value, you should replace sen-
sor.

4. Spread sealing glue to screw.

Stated sealing glue:

3M nut use NO.4171 or similar thing

to lock tightky.

5. Fix it and fasten it as stated torque.

6. Screw torque: 29 ± 10 N·M

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 BYD S6, S6A, S6K Service Manual

3.13 Checking oxygen sensor

1. Disassemble oxygen sensor connector,

use special tool (MB991316) to connect
it to one end of oxygen sensor.
Upstream cylinder
oxygen sensor

Upstream cylinder
oxygen sensor

Equipment side
connector

2. Measure resistance between sensor 1#

terminal and 3 # terminal, the resistance
Side connector should continuously change from 11-
of oxygen 18Ω (20°C).
Red
sensor
3. If the change isn’t continuous, replace it.
Blue
4. Warming up engine make its tempera-
ture more than 80°C.

5. Engine speed keep 4, 500 r/min and run

for over 5 minutes.

6. Connect data voltage meter to 2# (black

probe) and 4# terminal (white probe).

7. Engine runs, measure output voltage of

oxygen sensor.
Side connector Standard value:
Black of oxygen
sensor
Oxygen sensor output volt-
Engine
White age
Run 0.6 - 1.0 V

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 BYD S6, S6A, S6K Service Manual

NOTIE
• Connect test wire, don’t hurt oxygen
sensor.
• The input voltage of oxygen sensor
heater must be less than or equal
12V, or it will be hurt.

NOTICE
If can’t get to temperature (over 400°C),
even the oxygen sensor is normal, when
the air/fuel ratio is thick, it may be very
low. So, if the output voltage is low,
separately connect the wire to 1#( red
probe), to power (+) and 3# terminal( blue
probe) and to power (-), then check it.

8. If sensor isn’t well, replace it.

3.14 Checking injector

Checking action sound

Injector 1. Engine idle run, use stethoscope to

nozzle check injector action sound.

NOTICE
Even the injector hasn’t action, you may
also hear sound from others injector ac-
tion.

Equipnnent side connector 2. Make sure with engine speed increasing

injector sound increasing.

NOTICE
If can’t hear sound, check injector work
circuit.

Measure resistance:

1. Disassemble injector connector.

2. Measure resistance between terminals.

Standard value: 10.5-13.5Ω (at 20°C)

3. Connect injector.

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 BYD S6, S6A, S6K Service Manual

Check injector

Clamp 1. Use the method preventing fuel to spill.

Don’t make fuel spill, for oil pipe remain-
ing pressure.

2. Disassemble high pressure pipe.

3. Disassemble injector.

4. Use test equipment (MD998706) for in-

Injector nozzle jector

1) Fix injector to injector device pipe,

use injector clamp (MB991976) to
rectify.

2) Fix injector test connector to device

pipe connector.

3) Fold fuel pipe, fasten it with clamp

to prevent fuel leakage.

5. Fix test equipment (MD998706) to fuel

high pressure pipe.

6. Connector MUT-III to test connector.

7. Open ignition switch, but don’t start.

8. Choose 07 item from actuator action test

in MUT-III to test fuel pump.

9. Connect injector test wire (MB991607)

between injector and battery to start in-
jector.

10. Check fuel atomizing state.

High pressure fuel pipe 11. Stop injector action, check injector noz-
zle leakage situation, turn ignition switch
to “LOCK OFF” position, disassemble
MUT-III.

12. Start injector until it spill no more, draw

fuel from special tool.

13. Disassemble special tool.

14. If the fuel atomizing state is not well or

injector nozzle has the symptom of leak-
age, replace injector.

15. Assemble injector and high pressure fuel

pipe.

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 BYD S6, S6A, S6K Service Manual

3.15 Check throttle servo control

Check work

1. Disassemble intake hose from throttle

body.

2. Turn ignition switch to ON.

3. Step accelerate pedal to make sure

throttle valve can open and close
smoothly.

Check coil resistance

1. Disassemble electronic control throttle

valve.

2. Measure resistance between throttle

valve connector 1# terminal and 2# ter-
minal.
Electroruic thottle calve
Standard value: 0.3-100 Ω (at 20°C)

3. If resistance exceeds standard value, re-

Equipment side connector
place throttle body assembly.

3.16 Check oil control solenoid

Checking work

1. Disassemble oil control solenoid.

NOTICE
For avoid burning coil, keep voltage
Oil control solenoid stable as possible as you soon. (disas-
sembly action must be fast).

2. Connect battery voltage to oil control

Equiprnent valve terminal to make sure it sends out
side connector
the sound click.
Measure resistance between terminals

1. Disassemble oil control valve connector.

2. Measure resistance between control

valve terminals.
Standard value: 6.9-7.9 Ω (at 20°C)

3. If resistance exceeds standard value, re-

place it..

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 BYD S6, S6A, S6K Service Manual

3.17 Check engine ECU terminal

1. Connect thin probe to voltage meter.

2. Insert thin probe to all connector terminal of ECU, and refer to checking table to measure re-
sistance value of all terminals.

NOTICE
1. Measure voltage when ECU terminal is connected with wire harness connector.
2. Pull out wire harness connector a little from ECU terminal to make probe contact
connector terminal easily and check conveniently.
3. It is no necessary to check it as sequence in checking table.

NOTICE
If generate short circuit because insert into wrong terminal, the wire harness, sensor,
ECU or other elements will be hurt, so you must check it carefully.

3. If the consequence checking voltage value is different from standard value, check related
sensor, actuator and wire harness, if it is necessary to repair or replace it.

4. After repair or replace, check it once more with voltage meter to make sure whether the trou-
ble has been eliminated.

Different from M7.9 system, ECM of Mitsubishi system is consisted of five small connectors com-
position: A46, A47, A48, A49, A50 respectively, and each connector is numbered independently.
1. A46 connector

Pin NO. Pin definition Pin NO. Pin definition

1 Reserved 5 Cruise indicator control
2 EGR solenoid valve A 6 EGR solenoid valve B
3 Reserved 7 Reserved
Front oxygen sensor heating
4 1#injector signal control end 8
control

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 BYD S6, S6A, S6K Service Manual

Pin NO. Pin definition Pin NO. Pin definition

High speed cooling fan lower
9 19 ETV relay lower control end
control end
Fuel pump relay lower control
10 20 3#injector signal control end
end
11 Malfunction indicator signal drive 21 Reserved
12 Reserved 22 EGR solenoid valve D
13 2#injector signal control end 23 Reserved
14 Reserved 24 Reserved
15 EGR solenoid valve C 25 Canister control signal input
Rear oxygen sensor heating
16 26 Reserved
control
Low speed cooling fan lower
17 27 4#injector signal control end
control end
Air conditioner permission input
18
end

2. A47 Connector

Pin No. Pin definition Pin No. Pin definition

Non-lasting power input,12V Brake light switch signal
1 9
“ON” input,12V
Acceleration position sensor po-
2 ECM grounding 10
sition switch signal input end
3 2#ignition coil signal control end 11 Reserved
4 1#ignition coil signal control end 12 Reserved
Non-lasting power input,12V
5 13 3#ignition coil signal control end
“ON”
6 ECM grounding 14 Start signal input end
7 Reserved 15 IG1 power input
8 Reserved 16 Reserved

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 BYD S6, S6A, S6K Service Manual

Pin No. Pin definition Pin No. Pin definition

17 Reserved 23 Main relay lower control end
Power steering switch signal in-
18 24 Reserved
put end
Air conditioner request signal
19 25 Reserved
input end
Voltage regulator control ground-
20 26 Brake signal input end
ing
21 Reserved 27 Reserved
22 Power input ,constant power 28 4#ignition coil signal control end

3. A48Connector

Pin No. Pin definition Pin No. Pin definition

Input shaft position signal input
1 14 Reserved
end
2 Intake flow signal input 15 Reserved
3 CAN-L 16 Reserved
4 CAN-H 17 Speed signal input end
Input shaft position signal input
5 18 Reserved
end
Manual mode upshift signal in-
6 Reserved 19
put end
7 Camshaft position signal input 20 “D”signal input end
8 Crankshaft position signal input 21 “N”signal input end
Air conditioning medium voltage
9 22 Diagnostic “K” line
signal input
Manual mode downshift signal
10 23 Knock signal input control
input end
11 “R”signal input 24 Sensor interior grounding
12 “P”signal input 25 Engine speed input end
Voltage regulator control signal
13 Reserved 26
input

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 BYD S6, S6A, S6K Service Manual

Pin No. Pin definition Pin No. Pin definition

27 Manual mode signal input end 29 Speed signal input end
28 Reserved

4. A49 Connector

Pin NO. Pin definition Pin NO. Pin definition

1 Oil control valve signal input 16 Reserved
2 Cruise control signal input 17 Reserved
3 Reserved 18 Front oxygen sensor signal input
Acceleration position sensor
4 19 Reserved
master signal power supply
Acceleration position sensor Acceleration position sensor
5 20
master signal interior grounding secondary signal input end
Throttle position sensor power
6 Reserved 21
input end
Throttle position sensor ground-
7 Reserved 22
ing
8 Reserved 23 Reserved
Transmission oil temperature
9 Reserved 24
signal input end
10 Reserved 25 Reserved
11 Intake temperature signal input 26 Rear oxygen sensor signal input
Coolant temperature sensor
12 27 Reserved
power signal
Acceleration position sensor Throttle position master signal
13 28
secondary signal power supply input end
Acceleration position sensor
14 Sensor interior grounding 29
master signal input end
Throttle position secondary sig-
15 Reserved 30
nal input end

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 BYD S6, S6A, S6K Service Manual

5. A50 Connector

Pin NO. Pin definition Pin NO. Pin definition

Electronic throttle motor control
1 Non-lasting power input 14
signal input (-)
2 Non-lasting power input 15 Reserved
3 Reserved 16 ECM grounding
4 First gear signal input end 17
Electronic throttle motor control
5 18
signal input (+)
6 Non-lasting power input 19
7 ECM grounding 20 Reserved
8 21 Third gear signal input end
9 Reserved 22 Cruise control grounding end
10 23 ECM grounding
11 AT relay lower control end 24 ECM grounding
12 Reserved 25 Reserved
13 Second gear signal input end 26 Forth gear signal input end

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 BYD S6, S6A, S6K Service Manual

3.18 Trouble Symptom Checking Table

ITEM TROUBLE SYMPTOM SEQUENCE

Can’t use MUT-III Can’t communicate with engine ECU 1
Turn ignition switch to ON, but engine warning lamp can’t be on
Engine warning 2
immediately.
lamp
Engine warning lamp can’t misfire 3
4 <M/T>,
Can’t start (non ignition) Starter can’t work
5 <A/T>
Can’t start (starter run, but Starter work and crankshaft rotate,
6
non ignition) but cylinder can’t ignite.
Start
Can’t start (can ignite, but
Soon after start, misfire.
can’t be maintained)
7
The start type is wrong
Start engine for long time
(start for lone time)
Engine idle isn’t stable, the com-
mon way to judge is to use ta-
Idle isn’t stable
chometer or feel steering wheel,
Idle isn’t stable shift lever and body vibration 8
Idle is wrong Can’t get to proper idle
Engine misfire when idle Engine misfire when idle
When stepping accelerate pedal,
When starting, misfire 9
engine misfire.
Engine misfire
When deceleration, mis-
When deceleration, engine misfire. 10
fire.
When stepping accelerate pedal,
Engine can’t speed 11
engine can’t speed.
Acceleration sluggish means that
the vehicle speed can’t be lift im-
mediately and acceleration action
is sluggish or engine speed is
Sluggish acceleration is
decreased temporarily when ac-
celeration and stepping acceler-
ate pedal. The serious sluggish is
called “drop”.
Bad acceleration means the effect
to acceleration can’t get the target
speed according to throttle open.
Bad acceleration 12
When running (Although the acceleration pro-
cess is smooth) or get the highest
speed.
Maladjustment acceleration means
Maladjustment accelera- that when stepping accelerate
tion pedal, engine speed can’t lift im-
mediately.
The vehicle is running at equal
speed and small load, when speed
Vibration
is changed, the vehicle will vibrate
front and rear.
When vehicle is acceler-
When engine is acceleration you
ating, you will feel strong 13
will feel strong impact or vibration.
impact or vibration.

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 BYD S6, S6A, S6K Service Manual

ITEM TROUBLE SYMPTOM SEQUENCE

When deceleration, you
When deceleration, you will feel
will feel strong impact or 14
strong impact or vibration.
vibration.
When running When running, engine will produce
Knock 15
sharp knock sound.
Ignition timing set off Basic ignition timing set off. 16
After close ignition switch, engine
Misfire Continuously run 17
still run.
When idle, the gas has
When idle, the gas has peculiar
peculiar smell, white and
smell, white and black smoke, and
Exhaust gas black smoke, and the con- 18
the concentration of CO/HC is too
centration of CO/HC is too
high.
high
Battery is exhausted or its charging
Charging ability Battery is exhausted 19
ability isn’t well
Too high Engine temperature is too high 20

Water temperature When open ignition switch, fan

Fan motor is abnormal motor abnormally work.(no related 21
with water temperature)

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 BYD S6, S6A, S6K Service Manual

4. Diagnostic Trouble Code Procedures

4.1 DTC Check Program

P0030/0031/0032/0130/0131/0132/0133/0134: Front oxygen sensor system

Accumulator

EMS
Main
relay

Main
relay

Front oxygen
sensor Shielding layer
Shielding layer

CIRCUIT OPERATION:

• Front oxygen sensor (terminal 4#) output signal to ECU (A49-14)

• Front oxygen sensor (terminal 3#) are grounded with ECU (A49-19)

PRINCIPLE FUNCTION:

• Front oxygen sensor transforms the oxygen concentration of emission to voltage signal and
output it to ECU.

• When the air fuel ratio is more than air fuel ratio in theory, the output voltage of front oxygen
sensor is approximately 1V. When the air fuel ratio is less than air fuel ration theory, the out-
put voltage is 0V.

• The reaction signal of ECU make the air fuel ratio more closed the air fuel ratio in theory.

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 BYD S6, S6A, S6K Service Manual

JUDGEMENT CRITERION:

• When the ECU input 5 volts to oxygen sensor, output voltage of oxygen sensor is approxi-
mately 4.5 volts.

Check conditions Most likely causes

• 3 minutes or more have passed since the • Oxygen sensor failed
engine starting sequence was completed.
• Short circuit of oxygen sensor inner or connector
• Engine water temperature ≥ 80°C is faulty
• Engine speed ≥ 1200r/min • ECU failed
• Volumetric efficiency ≥ 25%
• Run with low load and constant speed

Diagnosis process

1. MUT-III data stream test. Refer to the

data stream test table

If normal, intermittent defect. If abnor-

mal, go to next step.

2. Check oxygen sensor connector A20.

If abnormal, repair or replace. If normal,

go to next step.

3. Measure the resistance of connector

A20-4

• Disconnect the connector, measure

the wiring harness side.

• Measure the resistance value be-

tween terminal 2# and grounding.
Standard value: ≤ 2 Ω

If normal, go to step 7. If abnormal, go to

next step

4. Check the connector A49 of engine.

If abnormal, repair or replace. If normal,

go to next step.

5. Check the wiring harness between the

connector A20 (termina4#) and A46 (ter-
minal 8#) of oxygen sensor (front).

• Check whether the ground is dis-

connected or damaged.

If abnormal, repair it. If normal, go to

next step.

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BYD S6, S6A, S6K Service Manual

6. MUT-III data stream test. Refer to data

stream test table.

If normal, intermittent defect. If abnor-

mal, replace the ECU.

7. Measure the terminal voltage of connec-

tor A20.

• Use special tool MB991316 to con-

nect terminal and measure it.

• Measure after warming up the en-

gine

• The voltage between terminal 1#

and ground
Standard: When the engine speed is 2,
500 r/min, the output voltage should
repeat 0-0.4 V or 0.6 - 1.0 V alternately.

If normal, go to step 10. If abnormal, go

to next step.

8. Check the oxygen sensor. If abnormal,

replace it. If normal go to next step.

9. Check the ECU connector A49.

If normal, check or repair the wiring har-

ness between oxygen sensor connector
A20 (terminal 3#) and the ECU connec-
tor A49 (terminal 19#).

• Check the damaged output wire

If abnormal, repair or replace it.

10. Measure the voltage of ECU connector

A49.

• Measure the ECU terminal voltage

• Measure after warming up engine

• The voltage between terminal 14#

and ground
Standard: When the engine speed is 2,
500 r/min., output voltage should re-
peat 0-0.4 V or 0.6 - 1.0 V alternately.

If normal go to step 12. if abnormal go to

next step.

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 BYD S6, S6A, S6K Service Manual

11. Check the ECU connector A49.

If normal, check or repair the wiring har-

ness between the oxygen sensor con-
nector A20 (termina3#) and ECU con-
nector A49 (terminal 19#)

• Check if the output wire is dam-

aged

If abnormal, repair or replace it.

12. Check the ECU connector A49.

If normal, go to step 6. if abnormal, re-

pair of replace it.

P0105/0106/0107/0108/0109/0110/0111/0112/0113 Intake air pressure sensor system

Main relay

PRINCIPLE FUNCTION:

• The intake air temperature sensor transforms intake air temperature into voltage signal and
outputs signal to ECU.

• ECU reflects single corrects the amount of fuel injection.

• Intake air temperature sensor is a kind of resistance. The resistance value is decreased

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 BYD S6, S6A, S6K Service Manual

when the temperature rises. So the output voltage of sensor varies with the intake air tem-
perature. Namely when the intake air temperature rises, the voltage is decreased.

JUDGEMENT CRITERION:

• Output voltage of sensor ≥ 4.6 V and maintain 4seconds (intake air temperature ≤ -40°C) or

• Output voltage of sensor ≤ 0.2 V and maintain 4seconds s(intake air temperature ≥ 120°C)

Check Conditions Most Likely Causes

• 2 seconds or more after turned the ignition • Air temperature sensor failed
switch on or engine starts
• Inner short circuit or the connector faulty
• ECU failed

Diagnosis Process

1. MUT-III data stream test.

• Item 13: Intake air temperature

sensor

Standard value: environment tempera-

ture or air temperature.

If normal, intermittent defect. If abnor-

mal, go to next step.

2. Check connector A14.

If abnormal, repair or replace it. If nor-

mal, go to next step.

3. Check intake air temperature sensor.

If abnormal, repair or replace it. If nor-

mal, go to next step.

4. Measure the resistance of connector

A14.

• Remove the connector., measure

the harness side

Measure the resistance between termi-

nal 1# and the ground

Standard valve: ≤ 2 Ω

If normal, go to step8. If abnormal, go to

next step.

5. Check ECU connector A49.

If normal, go to step 9. If abnormal, go to

next step.

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 BYD S6, S6A, S6K Service Manual

6. Check the harness between connector

A14 (terminal 1#) and connector A49
(terminal 14#).

NOTICE
Before checking harness, first check
middle connector, If necessary, replace
it.

• Check if the ground is open circuit

or damaged

If abnormal, repair it. If normal, go to

next step.

7. MUT-III data stream test. Refer to data

stream test table

• Item 13: air temperature sensor

Standard value: environment temper-
ature or air temperature.

If normal, intermittent defect. If abnor-

mal, replace ECU.

8. Measure the voltage of connector A14.

• Remove the connector, measure

the harness side resistance

• Turn the ignition switch on

• Measure the voltage between ter-

minal 4# and the ground
Standard value: 4.5 - 4.9 V

If normal, replace ECU. If abnormal, go

to next step.

9. Measure the voltage of ECU connector

A49.

• Measure the terminal voltage of

ECU

• Remove the air flow sensor con-

nector A14

• Turn the ignition switch on

• Measure the voltage between ter-

minal 11# and the ground
Standard value: 4.5 - 4.9 V

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BYD S6, S6A, S6K Service Manual

If abnormal, go to step 11. If normal, go

to next step.

10. Check the ECU connector A49.

If normal, check and repair the harness

between connector A14 (terminal 4#)
and connector A49 (terminal 11#).

• Check if the output wire is open cir-

cuit

If abnormal, repair or replace it.

11. Check the ECU connector A49.

If abnormal, repair or replace it. If nor-

mal, go to next step.

12. Check the harness between connector

A14 (terminal 1#) and connector A49
(terminal 14#).

• Check if the output wire is short cir-

cuit

If normal, go to step 7. If abnormal, re-

pair it.

13. Measure the voltage of connector A14.

• Connect terminal 1# and terminal

4# using special tool MB991709

• Turn the ignition switch on

• Measure the voltage between ter-

minal 4# and the ground
Standard value:

Environment temperature is -20°C: 3.8

- 4.4 V

Environment temperature is 0°C: 3.2 -

3.8 V

Environment temperature is 20°C: 2.3

- 2.9 V

Environment temperature is 40°C: 1.5

- 2.1 V

Environment temperature is 60°C: 0.8

- 1.4 V

Environment temperature is 80°C: 0.4

- 1.0 V

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 BYD S6, S6A, S6K Service Manual

If normal, go to step 7. If abnormal, go to

next step.

14. Check the ECU connector A49.

If abnormal, repair or replace it. If nor-

mal, go to next step.

15. Check the harness between connector

A14 (terminal 1#) and connector A49
(terminal 14#)

• Check if the output wire is dam-

aged

If normal, go to step 7. If abnormal, re-

pair it.

P0122/0123 Throttle position sensor

CIRCUIT OPERATION:

• ECU (terminal A49-21#) provides 5 volts for electronic control throttle (terminal 2#)

• Electronic control throttle (terminal 4#) is grounded with ECU (terminal A49-22#)

• Electronic control throttle (terminal A17-3#) outputs signal to ECU (terminal A49-28#)

PRINCIPLE FUNCTION:

• Throttle position sensor (TPS) transform the throttle position for voltage signal and input it to
ECU.

• ECU controls the throttle position sensor

JUDGEMENT CEITERION:

• Output voltage of throttle position sensor(sub) ≤ 2.2 V or ≥ 4.8 V

• Output voltage of throttle position sensor(main) ≥ 2.5 V and output voltage of throttle position
sensor (sub) ≤ 4.2 V.

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 BYD S6, S6A, S6K Service Manual

Check Conditions Most Likely Causes

• Turned the ignition switch on • Throttle position sensor failed
• Output voltage of throttle position sensor (main) • Wiring harness short circuit or bad contact
is between 0.2 V-4.8 V
• Wiring harness damaged or bad contact
• Output voltage of throttle position sensor (sub)
• ECU failed
is between 2.2 V-4.8 V

Diagnosis Process

1. MUT-III data stream test. Refer to data

stream test table

If abnormal, go to step 3. If normal, go to

next step.

2. MUT-III data stream test. Refer to data

stream test table

If normal, intermittent defect. Check TPS

(main)

3. Check the connector A17 of electronic

control throttle.

If abnormal, repair or replace it. If nor-

mal, go to next step.

4. Measure the voltage of electronic control

TPS valve connector.
• Remove the connector, measure
the harness side
• Ignition switch: ON
• Voltage between terminal 2# and
the ground
Standard value: 4.9 - 5.1 V

If normal, go to step 8. If abnormal, go to

next step.

5. Check the ECU connector A49.

If abnormal, repair or replace it. If nor-

mal, go to next step.

6. Check the harness between connector

A17 (terminal 2# ) of electronic control
TPS valve and ECU connector A49 (ter-
minal 21#).

• Check if the power cords are open

circuit or short circuit

If abnormal, repair it. If normal, go to

next step.

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 BYD S6, S6A, S6K Service Manual

7. MUT-III data stream test. Refer to data

stream test table

If normal, intermittent defect. If abnor-

mal, replace ECU.

8. Measure the resistance of connector

A17.

• Remove the connector, measure

the harness side

• Measure the resistance between

terminal 4# and the ground
Standard value: ≤ 2 Ω

If normal, go to step 12. If abnormal, go

to next step.

9. Check the ECU connector A49.

If abnormal, repair or replace it. If nor-

mal, go to next step.

10. Check the harness between connector

A17 (terminal 4#) of electronic control
TPS valve and ECU connector A49 ter-
minal 22#).

• Check if the ground wire is open

circuit or damaged

If abnormal, repair it. If normal, go to

next step.

11. MUT-III data stream test. Refer to data

stream test table

If normal, intermittent defect. If abnor-

mal, replace ECU.

12. Check the ECU connector A49.

If abnormal, repair or replace it. If nor-

mal, go to next step.

13. Check the harness wire between elec-

tronic throttle valve connector A17 (ter-
minal 2#)) and engine ECU connector
A49 (terminal 21#)

• Check if the power cord is dam-

aged

If abnormal, repair it. If normal, go to

next step.

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BYD S6, S6A, S6K Service Manual

14. Check the harness wire between elec-

tronic throttle valve connector A17 (ter-
minal 3#))and ECU connector A49 (ter-
minal 28#).

• Check if the output wire is open/

short circuit and damaged

If abnormal, repair it. If normal, go to

next step.

15. MUT-III data stream test. Refer to data

stream test table

If normal, intermittent defect.

If abnormal, replace the throttle body as-

sembly, and go to next step.

16. Read the DTC of MUT-III.

If the DTC occurs, replace ECU, if no

DTC, check harness wire.

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 BYD S6, S6A, S6K Service Manual

P0117/0118 Engine coolant temperature sensor system

Coolant temperature
sensor system

ECM

CIRCUIT OPERATION:

• ECU (terminal A49-12#) outputs 5 volts to the output terminal (terminal 2#) of engine water
temperature sensor

• The engine water temperature sensor (terminal 1#) is grounded with ECU A49-14.

PRINCIPLE FUNCTION

• The engine water temperature sensor transforms the water temperature to voltage signal
and inputs to ECU

• ECU output signal to control the fuel injection quantity, and controls the high idle speed when
cooling states

• Engine water temperature sensor is a kind of resistance whose resistance value will de-
crease with the water temperature increase, so the output voltage changes with the tempera-
ture changes, that is the water temperature increase will decrease the resistance.

Check Conditions Most Likely Causes

1 2 seconds or more after turning the ignition • Engine water temperature sensor failed
switch on or just running the engine, output
• Short circuit or bad contact
voltage of sensor ≥ 4.6 V and maintain 2
seconds (water temperature ≤ -45°C) or output • ECU failed
voltage ≤ 0.1 V (water temperature ≥ 140°C)
and maintain 2 seconds).
2 After starting the engine. The engine water
temperature over 40°C or lowers than 40°C and
maintain 5 minutes.

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BYD S6, S6A, S6K Service Manual

Diagnosis Process:

1. MUT-III data stream test. Refer to data

stream test table
Standard: Cooling engine: Environ-
ment temperature (air temperature)

Engine warming: 80 - 120°C

If normal, intermittent defect. If abnor-

mal, go to next step.

2. Check connector A21 of engine temper-

ature sensor

If abnormal, repair or replace it. If nor-

mal, go to next step.

3. Measure the resistance of engine water

temperature sensor

• Remove the connector, measure

the sensor side harness

• Measure the resistance between

connector 1# and terminal 2#
Standard value:

Water temperature is-20°C: 14 - 17 kΩ

Water temperature is 0°C: 5.1 - 6.5 kΩ

Water temperature is 20°C: 2.1 - 2.7 kΩ

Water temperature is 40°C: 0.9 - 1.3 kΩ

Water temperature is 60°C: 0.48 - 0.68 kΩ

Water temperature is 80°C: 0.26 - 0.36 kΩ

If abnormal, replace it. If normal, go to

next step.

4. Measure the resistance of water tem-

perature sensor.

• Remove the connector, measure

the harness side

• Measure the resistance between

terminal 2# and the ground.
Standard value: ≤ 2 Ω

If normal, go to step 8. If abnormal, go to

next step.

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 BYD S6, S6A, S6K Service Manual

5. Check the ECU connector A49.

If abnormal, repair or replace it. If nor-

mal, go to next step.

6. Check the harness between connector

A21 (terminal 1#) of water temperature
sensor and ECU connector A49 (terminal
14#).

CAUTION
Should check middle connector ACJ05
before check the harness, replace it if
necessary

• Check if the ground wire is open

circuit or damaged

If abnormal, repair it. If normal, go to

next step.

7. MUT-III data stream test. Refer to the

data stream test table
Standard: Engine cooling: Environ-
ment temperature (air environment)

Engine warming: 80 - 120°C

If normal, intermittent defect. If abnor-

mal, replace ECU.

8. Measure the voltage of water tempera-

ture sensor connector A21.

• Remove the connector, measure

the harness side

• Ignition switch: ON

• Voltage between terminal 2# and

the ground
Standard value: 4.5 - 4.9 V

If normal, go to step11. If abnormal, go

to next step.

9. Measure the voltage of ECU connector

A49.

• Measure the terminal voltage of

ECU.

• Remove the water temperature

sensor connector A21.

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BYD S6, S6A, S6K Service Manual

• Ignition switch: ON

• Measure the voltage between ter-

minal12# and ground
Standard value: 4.5 - 4.9 V

If abnormal, go to step 11. If normal, go

to next step.

10. Check ECU connector A49.

If normal, check or repair the harness

between connector A21 (terminal 2#)
and connector A49 (terminal 12#).

• Check if the output circuit is open

circuit

If abnormal, repair or replace it.

11. Check the ECU connector A49.

If abnormal, repair or replace it. If nor-

mal, go to next step.

12. Check the harness between connector

A21 (terminal 2#) and connector A49
(terminal 12#).

• Check if the output wires are short

circuit

If abnormal, repair it. If normal, go to

step 7.

13. Measure the voltage of water tempera-

ture sensor connector A21.

• Use special tool MB991658 to con-

nect the connector and measure

• Ignition switch: ON

• Measure the voltage between ter-

minal 2# and ground
Standard value:

Water temperature is-20°C: 3.9 - 4.5 V

Water temperature is 0°C: 3.2 - 3.8 V

Water temperature is 20°C: 2.3 - 2.9 V

Water temperature is 40°C: 1.3 - 1.9 V

Water temperature is 60°C: 0.7 - 1.3 V

Water temperature is 80°C: 0.3 - 0.9 V

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 BYD S6, S6A, S6K Service Manual

If normal, go to step 7. If abnormal, go to

next step.

14. Check the ECU connector C-113.

If abnormal, repair or replace it. If nor-

mal, go to next step.

15. Check the harness between connector

A21 (terminal 2#) and connector A49
(terminal 12#).

• Check if the output wire is dam-

aged

If abnormal, repair it. If normal, go step 7.

P0321/0322: Crankshaft position sensor

Main
relay
Crankshaft position sensor

CIRCUIT OPERATION:

• Power is provided for crankshaft angle sensor(terminal 3#) from engine control relay (terminal
1#), and terminal 1# is grounded with ECU (terminal A48-24#)

• ECU (terminal A48-8#) provides 5 volts power for crankshaft angle sensor (terminal 2#)

PRINCIPLE FUNCTION:

• Crankshaft angle sensor detects the crankshaft angle (position) and input a pulse signal to
ECU

• The reaction signal of ECU controls the injector and so on

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 BYD S6, S6A, S6K Service Manual

JUDGEMENT CRITERION:

• The no change times of crankshaft angle sensor output voltage maintain 2 seconds (no
pulse signal)

Check Conditions Most Likely Causes

• Engine running • Crankshaft angle failed
• Short circuit or bad contact
• ECU failed

Diagnosis Process:

1. MUT-III data stream test. Refer to data

stream test table

If normal, intermittent defect. If abnor-

mal, go to next step.

2. Check the sensor middle connector A22.

If abnormal, repair or replace it. If nor-

mal, go to next step.

3. Measure the voltage of sensor middle

connector A22.

• Remove the connector, measure

the harness wire

• Ignition switch: ON

• Measure the the voltage between

terminal 2# and ground
Standard value: 4.9 - 5.1 V

If normal, go to step 9. If abnormal, go to

next step.

4. Measure the voltage of ECU connector

A48

• Measure the terminal voltage of

ECU

• Remove the middle connector A22

of crankshaft angle sensor

• Ignition switch: ON

• Measure the voltage between ter-

minal 8# and ground
Standard value: 4.9 - 5.1 V

If abnormal, go to step 6. If normal, go to

next step.

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 BYD S6, S6A, S6K Service Manual

5. Check the ECU connector A48.

If normal, check and repair the harness

between connector A22 (terminal 2#)
and A48 (terminal 8#)

• Check the output wire open circuit

If abnormal, repair or replace it.

6. Check the ECU connector A48.

If abnormal, repair or replace it. If nor-

mal, go to next step.

7. Check and repair the harness between

connector A22 (terminal 2#)and A48 (ter-
minal 8#).

• Check the output wire short circuit

If abnormal, repair or replace it. If nor-

mal, go to next step.

8. MUT-III data stream test. Refer to data

stream test table

If normal, intermittent defect. If abnor-

mal, replace a new ECU.

9. Measure the voltage of middle connector

A22.
• Remove the connector, measure
the harness side
• Ignition switch: ON
• Measure the voltage between ter-
minal 1# and ground
Standard value: system voltage

If normal, go to step 11. If abnormal, go

to next step.

Connector: B-15X Relay box’s 10. Check the connector G2X-29 of engine
triangle marks relay.

If normal, check middle connector AJ54,

B-15X replace it if necessary. If the middle con-
nector is normal, check and repair the
harness between connector A22 (termi-
Harness nal 3#) and connector G2X-29 (terminal
side connector
3#) of engine relay.

Check if the power cords are short circuit

or open circuit

If abnormal, repair or replace it.

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 BYD S6, S6A, S6K Service Manual

Connector: B-121 11. Measure the resistance of connector

A22.

• Remove the connector measure-

B-121 (GR) ment harness.

• Measure the resistance between

terminal 1 and ground
Harness Standard value: ≤ 2 Ω
side connector
12. Check the ECU connector A48.

If abnormal, repair or replace it. If nor-

mal, go to next step.

13. Check and repair the harness between

Connector: C-112
<L.H. drive vehicles> connector A22 (terminal 3#) and G2X-
29.

CAUTION
Should check middle connector AcJ04
before check the harness, replace if nec-
C-112 (GR)
essary.
<R.H. drive vehicles> • Check the power cord damaged

If normal, go to step 8. If abnormal, re-

pair it.

14. Check the output wave of crankshaft

C-112 (GR)
angle sensor middle connector B-121.

• Use special tool MB991658 to con-

nect the connector to measure
Harness side connector
• Engine: Idle

• Measure the voltage between ter-

minal 2# and the ground.

Standard: Max value ≥ 4.8 V, Min.val-

ue ≤ 0.6 V

If normal, go to step 8. If abnormal, go to

next step

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 BYD S6, S6A, S6K Service Manual

Connector: B-15X Relay box’s 15. Check the connector B-15X of engine
triangle marks control relay.

If abnormal, repair or replace it. If nor-

B-15X mal, go to next step.

16. Check the harness between connector

Harness A22 (terminal 1#) and G2X-29 (terminal
side connector
1#)

CAUTION
Should check middle connector AcJ04
before check the harness, replace if nec-
essary.

• Check the power cord damaged

If abnormal, repair or replace it. If nor-

mal, go to next step.

17. Check the ECU connector A48.

If abnormal, repair or replace it. If nor-

mal, go to next step.

18. Check the harness between middle con-

nector A22 (terminal 2#) and ECU con-
nector A48 (terminal 8#).

• Check the output wire damaged

If abnormal, repair it. If normal, go to

next step.

19. Check the harness between middle con-

nector A22 (terminal 1#) and ECU con-
nector A48 (terminal 24#).

• Check the ground wire damaged

If abnormal, repair it. If normal, go to

next step.

20. Check the connector A22-1 of crankshaft

angle sensor

If abnormal, repair or replace it. If nor-

mal, go to next step.

21. A22 and crankshaft angle sensor con-

nector A22-1.

• Check power cord open/short cir-

cuit and damaged

• Check output wire open/short cir-

cuit and damaged

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 BYD S6, S6A, S6K Service Manual

Connector: B-15X Relay box’s • Check ground wire open/short cir-

triangle marks cuit and damaged

If abnormal, replace the timing belt cov-

B-15X er. If normal, go to next step.

22. Check the crankshaft angle sensor lami-

Harness na.
side connector
If abnormal, replace the lamina of crank-
shaft angle sensor. If normal, go to next
step.

23. MUT-III data stream test. Refer to data

stream test table

If normal, intermittent defect. If abnor-

mal, replace a new crankshaft sensor.

P0340/0341/0342/0343: Camshaft position sensor

Main relay
Camshaft position
sensor

CIRCUIT OPERATION:

• Engine control relay (terminal 1#) outputs power source to camshaft position sensor (terminal
1#), the camshaft position sensor (terminal 2#) is grounded with ECU (terminal 24#)

• A 5 volts voltage is applied on the camshaft position sensor output terminal (terminal 2#)
from the ECU (termina7#)

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 BYD S6, S6A, S6K Service Manual

PRINCIPLE FUNCTION:

• The camshaft position sensor detects the top dead center position of the number 1 cylinder
dam to convert that data to pulse signals that are input to the ECU

JUDGEMENT CRITERION:

• The times of camshaft position sensor output voltage (no pulse signals) is unchanged and
maintain 2 seconds or more

Check Conditions Most Likely Causes

• 2 seconds or more passed after turned the • Camshaft position sensor failed
ignition switch on or the engine running.
• Wire harness is shore circuit or bad contact
• Engine speed ≥ 500 r/min.
• ECU failed

Diagnosis Process:

Connector: B-114 1. Check the camshaft position sensor con-

nector A05.

If abnormal, repair or replace it. If nor-

B-114 (B)
mal, go to next step.

2. Measure the voltage of camshaft posi-

tion sensor connector A05.
Harness
side connector • Remove the connector, measure
the harness side

• Ignition switch: ON

• Measure the voltage between ter-

minal 1# and ground
Standard value: System voltage

If normal, go to step 4. If abnormal, go to

next step.

3. Check the engine control relay connec-

tor G2X-29.

If normal, check the middle connector

AJ54, replace if necessary. If normal,
check the harness between camshaft
position sensor connector A05 (terminal
1#) and control relay connector G2X-29
(terminal 1#).

• Check open/short circuit for power

cords

If abnormal, repair or replace it.

4. Measure the voltage of camshaft posi-

tion sensor connector A05.

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 BYD S6, S6A, S6K Service Manual

Connector: B-114 • Remove the connector, measure

the harness side

• Ignition switch: ON
B-114 (B)
• Measure the voltage between ter-
minal 2# and ground

Harness Standard value: 4.9 - 5.1 V

side connector
If normal, go to step 10. If abnormal, go
to next step.

5. Measure the voltage of ECU connector

A48.

• Disconnect the A05

• Ignition switch: ON

• Measure the voltage between ter-

minal 7# and ground
Standard value: 4.9 - 5.1 V

If abnormal, go to step 7. If normal, go to

next step.

6. Check the ECU connector A48.

If normal, check and repair the harness

between connector A05 (terminal 2#)
and A48 (terminal7#).

• Check open circuit for output wires

If abnormal, repair or replace it.

7. Check the ECU connector A48

If abnormal, repair or replace it. If nor-

mal, go to next step.

8. Check the harness between connector

A05 (terminal 2#) and A48 (terminal 7#).

• Check short circuit for output wires

If abnormal, repair it. If normal, go to

next step.

9. Read the MUT-III DTC.

If DTC occurs, replace the ECU, if no

DTC, intermittent defect.

10. Measure the resistance of camshaft po-

sition sensor connector A05.

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 BYD S6, S6A, S6K Service Manual

Connector: B-114 • Remove the connector, measure

the harness side

• Measure the resistance of terminal

B-114 (B)
3#.
Standard value: ≤ 2 Ω

Harness If normal, go to step 13. If abnormal, go

side connector to next step.

11. Check the ECU connector A48.

If normal, go to next step. If abnormal,

repair or replace it.

12. Check the harness between connec-

tor A05 (terminal 1#) and A48 (terminal
24#).

CAUTION
Should check the connector AJ54 before
check the wires, replace if necessary.

• Check the open circuit and dam-

aged for the ground wires

If abnormal, repair it. If normal, go to

step 9.

13. Measure the output waveform of cam-

shaft position sensor connector A05

• Connect the connector using spe-

cial tool MB991709.

• Engine: idle

• Measure the voltage between ter-

minal 2# and ground
Standard: Max value ≥ 4.8 V

Min value ≤ 0.6 V

If normal, go to step 9. If abnormal, go to

next step.

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 BYD S6, S6A, S6K Service Manual

Connecor: B-15X Relay box’s 14. Check the engine relay connector G2X-
triangle marks 29.

If abnormal, repair or replace it. If nor-

B-15X
mal, go to next step.

15. Check the harness between connector

Harness side A05 (terminal 1#) and G2X-29 (terminal
connector 1#).

CAUTION
Should check the connector AcJ08 be-
fore checking the wires, replace it if nec-
essary.

• Check the damage for power cords

If abnormal, repair it. If normal, go to
next step.

16. Check the ECU connector A48.

If abnormal, repair or replace it. If nor-

mal, go to next step.

17. Check the harness between connector

A05 (terminal 2#) and A48 (terminal7#).

CAUTION
Should check connector AcJ08 before
checking wires, replace it if necessary.

• Check damaged for the output

wires
If abnormal, repair it. If normal, go to
next step.

18. Check the harness between connector

A05 (terminal 1#) and G2X-29.

CAUTION
Should check the connector AcJ08 be-
fore checking the wires, replace it if nec-
essary.

• Check the damage for the ground

wires
If abnormal, repair it. If normal, go to
next step.
19. Check the camshaft position sensor.

If abnormal, replace it. If normal, go to

next step.

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 BYD S6, S6A, S6K Service Manual

Connecor: B-15X Relay box’s 20. Read the MUT-III DTC.

triangle marks
If DTC occurs, replace camshaft position
sensor. If no DTC, intermittent defect.
B-15X

Harness side
connector

DTC 25: Atmospheric pressure sensor system

PRINCIPLE FUNCTION:

• Senor converts the atmospheric pressure to voltage signal and input to ECU

JUDGEMENT CRITERION:

• Sensor output voltage ≥ 4.5V (atmospheric pressure ≥ 114Kpa) and maintain 2 seconds or
more

• Sensor output voltage ≤ 0.2V (atmospheric pressure ≤ 53Kpa) and maintain 2 seconds or
more

Check Conditions Most Likely Causes

• 2 seconds or more passed after starting the • Atmospheric pressure sensor failed
engine or turning the ignition switch on
• Battery voltage ≥ 8V

Diagnosis Process:

1. Read the MUT-III DTC.

If DTC occurs, replace the ECU. If no DTC, intermittent defect.

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 BYD S6, S6A, S6K Service Manual

P0327/0328: Knock sensor

layer
Shield
layer
Shield
Knock sensor

CIRCUIT OPERATION:

• Knock sensor (terminal 2#) outputs signal to ECU (terminal A48-23#)

PRINCIPLE FUNCTION

• Knock sensor detects the vibration of cylinder and inputs signal to ECU

• ECU reacts signals to delay the ignition timing when knock occurs

JUDGEMENT CRITERION:

• Knock sensor output voltage (knock sensor peak voltage) has not changed more than 0.06
volts in the consecutive 200 periods.

Check Conditions Most Likely Causes

• 2 seconds or more passed after started engine • Knock sensor failed
• Engine speed is higher than 2, 500 r/min • Open harness circuit or bad contact
• Volumetric efficiency ≥ 30% • ECU failed

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 BYD S6, S6A, S6K Service Manual

Diagnosis Process:

Connector: B-24 1. Check the knock sensor connector A04.

If abnormal, repair or replace it. If nor-

mal, go to next step.
B-24 (GR)
2. Measure the resistance of knock sensor
connector A04.

Detonation sensor • Remove the connector, measure

Harness the harness side
side connector
• Measure the resistance between
terminal 1# and the ground
Standard value: ≤ 2Ω

If normal, go to next step. If abnormal,

check and repair the harness between
knock sensor connector A04 (terminal
1#) and the ground.

• Check open circuit or damaged for

the ground wire

3. Check the ECU connector A48.

If abnormal, repair or replace it. If nor-

mal, go to next step.

4. Check the harness between knock sen-

sor connector A04 (terminal 2#) and
ECU connector A48 (terminal 23#)

• Check open or short circuit and

damage for output wire

If abnormal, repair or replace it. If nor-

mal, go to next step.

5. Read the MUT-III DTC.

If DTC occurs, after replaced the knock

sensor, go to next step.

If no DTC, intermittent defect.

6. Read MUT-III DTC.

If DTC occurs, replace ECU. If no DTC,

check ends.

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 BYD S6, S6A, S6K Service Manual

P0136/0137/0138/0140 downstream oxygen sensor system

Accumulator

EMS
Relay
15A

Main
relay

Rear oxygen sensor

Shield layer
Shield layer

CIRCUIT OPERATION:

• Downstream oxygen sensor (terminal 3#) output signal to ECU (terminal A49-27#).

• Downstream oxygen sensor (terminal 2#) are grounded with ECU (terminal A46-16#)

PRINCIPLE FUNCTION

• Downstream oxygen sensor detects the concentration of oxygen in the exhaust gas and con-
verts those data to voltage signal to input to the ECU.

• When the air fuel ratio is higher than theory air fuel ratio, downstream oxygen sensor output
voltage is approximately 1 volt. When the air fuel ratio ≤ theory air fuel ratio, the output volt-
age is 0 volt.

• ECU react signals to control the injection quantity to make the air fuel ratio closed theory air
fuel ratio.

JUDGEMENT CRITERION:

• When 5 volts voltage is applied on the oxygen sensor, the oxygen sensor output voltage ≥ 4.5V

Check Conditions Most Likely Causes

• 3 minutes or more have passed after started the • Oxygen sensor failed
engine
• Oxygen sensor inner short circuit or bad
• Engine coolant temperature ≥ 80°C connector contact
• Engine speed ≥ 1200r/min • ECU failed
• Volumetric efficiency ≥ 25%
• Constant speed running with low load

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 BYD S6, S6A, S6K Service Manual

Diagnosis Process

1. MUT-III data stream test. Refer to data

stream test table

If normal, intermittent defect. If abnor-

mal, go to next step.

2. Check downstream oxygen sensor con-

nector A06. If abnormal, repair or replace
it. If normal, go to next step.

3. Measure the resistance of connector

A06.

• Remove the connector, measure

the harness side

• Measure the resistance between

terminal 4# and ground
Standard value ≤ 2 Ω

If normal, go to step 7.If abnormal, go to

next step.

4. Check the engine ECU connector A49.

If abnormal, repair or replace it. If nor-

mal, go to next step.

5. Check the harness between oxygen sen-

sor (front) connector A06 (terminal 4#)
and A49 (terminal 16#).

• Check if the ground is open or

damaged

If abnormal, repair it. If normal, go to

next step.

6. MUT-III data stream test. Refer to data

stream test table

If normal, intermittent defect. If abnor-

mal, replace ECU.

7. Measure the voltage of connector A06.

• Connect the terminals using spe-

cial tool MB991316 to measure

• Measure after warmed the engine

up

• Measure the voltage between ter-

minal 3# and ground

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BYD S6, S6A, S6K Service Manual

Standard: When the engine speed is

2, 500 r/min., output voltage should
repeat 0-0.4 V or 0.6-1.0 V alternately

If normal, go to step 10. If abnormal, go

to next step.

8. Check the downstream oxygen sensor.

If abnormal, replace it. If normal, go to
next step.

9. Check the ECU connector A49.

If normal, check or repair the harness

between downstream oxygen sensor
connector A06 (terminal 3#) and ECU
connector A49 (terminal 27#).

• Check the damaged for output sire

If abnormal, repair or replace it.

10. Measure the voltage of ECU connector

A49.

• Measure the ECU terminal voltage

• Check after warmed the engine up

• Measure the voltage between ter-

minal 27# and ground
Standard: When the engine speed is
2, 500 r/min., output voltage should
repeat 0-0.4 V or 0.6-1.0 V alternately.

If normal, go to step 12. If abnormal, go

to next step.

11. Check the ECU connector A49.

If normal, check or repair the harness

between downstream oxygen sensor
connector A06 (terminal 3#) and ECU
connector A49 (terminal 27#).
• Check damaged for output wire
If abnormal, repair or replace it.

12. Check the ECU connector A49.

If normal, go to step 6. If abnormal, re-

pair or replace it.

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 BYD S6, S6A, S6K Service Manual

P0201/0202/0203/0204/0261/0262/0264/0265/0267/0268/0270/0271: Injector system

Accumulator

EMS
Relay
15A

Main
relay
Fuel injector

Fuel injector

Fuel injector

Fuel injector

CIRCUIT OPERATION:

• Engine control relay (terminal G2X-17#) outputs power to the injector (terminal 2#)

• The ECU (terminal A46-4#, 13#, 20#, 27#) outputs currents to the injector (terminal 2#) by
turning the power transistor on

JUDGEMENT CRITERION:

• Injector coil surge voltage (battery positive voltage +2 volts) has not been detected for 4 sec-
onds

PRINCIPLE FUNCTION

• ECU control the power interval of injector

• The injection quantity depends on the power interval

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Check Conditions Most Likely Causes

• Do not make the MUT-III actuator test • Injector failed
• Engine speed is 50-1000 r/min • Open or shorted injector circuit, or bad contact
• Throttle position sensor (main) output voltage • ECU failed
≤ 1.15 V

Diagnosis Process

1. MUT-III executer test. Refer to the ex-

ecuter test table

• Item 01: 1# Injector

• Item 02: 2# Injector

• Item 03: 3# Injector

• Item 04: 4# Injector

Standard: Idle status changed

If idle speed has changed, intermittent

defect. If no change, go to next step.

Connectors: V-101, B-102, B-104, B-105 2. Check the injector connector.

1) A09 (1# Injector)

2) A10 (2# Injector)

3) A11 (3# Injector)

4) A12 (4# Injector)

Harness side connector If abnormal, repair or replace it. If nor-

mal, go to next step.

3. Measure the resistance of injector con-

nector.

1) A09 (1# Injector)

2) A10 (2# Injector)

3) A11 (3# Injector)

4) A12 (4# Injector)

• Disconnect the connector, measure

at the injector harness side

• Measure the resistance between

terminal 1# and 2#
Standard value: 10.5-13.5Ω

If abnormal, repair or replace it. If nor-

mal, go to next step.

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Connectors: V-101, B-102, B-104, B-105 4. Measure the voltage of injector connec-
tor.

1) A09 (1# Injector)

2) A10 (2# Injector)

3) A11 (3# Injector)

4) A12 (4# Injector)

Harness side connector
• Remove the connector, measure
the harness side
• Ignition switch: ON
• Measure the voltage between ter-
minal 2# and ground
Standard value: System voltage

If normal, go to step 6. If abnormal, go to

next step.

Connector: B-15X Relay box’s 5. Measure the engine relay connector

triangle marks G2X-17

If normal,

1) Check middle connector ACJ05,

replaces it if necessary. If the mid-
Harness side dle connector is normal, check and
connector repair the harness between 1# in-
jector connector A09 (terminal 2#)
and engine relay connector G2X-
17.
Connectors: V-101, B-102, B-104, B-105
2) Check middle connector ACJ05,
replaces it if necessary. If the mid-
dle connector is normal, check and
repair the harness between 2# in-
jector connector A10 ((terminal 2#)
and engine relay connector G2X-
17
Harness side connector 3) Check middle connectors ACJ05,
replace it if necessary. If the middle
connector is normal, check and re-
pair the harness between 3# injec-
tor connector A11 (terminal 2#) and
engine relay connector G2X-17.

4) Check middle connector ACJ05,

replace it if necessary. If the middle
connector is normal, check and re-
pair the harness between 4# injec-
tor connector A11 (terminal 2#) and
engine relay connector G2X-17

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Connectors: V-101, B-102, B-104, B-105 Check the short or open circuit for power
cord

If abnormal, repair or replace it.

6. Check the engine relay connector G2X-

17.

If abnormal, repair or replace it. If nor-

Harness side connector
mal, go to next step.

7. Check the harness between injector

connector A11 and engine control relay
connector G2X-17.

CAUTION
Should check middle connector ACJ05
before check the harness, replace it nec-
essary.

1) Check the harness between 1# in-

jector connector A09 (terminal 2#)
and engine control relay connector
G2X-17.

2) Check the harness between 2# in-

jector connector A10 (terminal 2#)
and engine control relay connector
G2X-17.

3) Check the harness between 3# in-

jector connector A11 (terminal 2#)
and engine control relay connector
G2X-17.

4) Check the harness between 4# in-

jector connector A12 (terminal 2#)
and engine control relay connector
G2X-17.

Check the damage for power cord

If abnormal, repair or replace it. If nor-

mal, go to next step.

8. Check the ECU connector A46.

If abnormal, repair or replace it. If nor-

mal, go to next step.

9. Check the harness between injector con-

nector and ECU connector A46.
1) Check the harness between 1# in-
jector connector A09 (terminal 1#)
and ECU connector A46 (terminal
4#).

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Connectors: V-101, B-102, B-104, B-105 2) Check the harness between 2# in-
jector connector A10 (terminal 2#)
and ECU connector A46 (terminal
13#).

3) Check the harness between 3# in-

jector connector A11 (terminal 2#)
and ECU connector A46 (terminal
20#).
Harness side connector
4) Check the harness between 4# in-
jector connector A12 (terminal 2#)
andECU connector A46 (terminal
27#).

Check the open or short output wire cir-

cuit, or damaged

If abnormal, repair it. If normal, go to

next step.

10. Waveform test of ECU connector A46.

• Engine: Idle
• Measure the voltage between ter-
minal 1# and ground.
Standard: waveform display

If normal, intermittent defect. If abnor-

mal, replace ECU.

P0300/0301/0302/0303/03041, 2, 3, 4 cylinder misfire

PRINCIPLE FUNCTION

• The engine speed will immediately change when the misfire occurs while the engine is run-
ning.

• ECU checks for such changes in engine speed

JUDGEMENT CRITERION: (change in the angular acceleration of the crankshaft is used for mis-
fire detection)

• Misfire has occurred more frequently than allowed during the last 200 revolutions when the
catalyst temperature is higher than 950°C

• Misfire has occurred in 15 times or more of the last 1, 000 revolutions (corresponding to 1.5
times the limit of emission standard)

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Check Conditions Most Likely Causes

• Engine speed: 500 - 6, 500 r/min. • Ignition switch related parts failed
• Water temperature ≥ -10°C • Low compression pressure
• Air pressure ≥ 76 kPa • ECU failed
• Volumetric efficiency is at between 30% and
55%
• The throttle deviation is ± -0.06 V/10 ms
• While the engine is running, sudden
acceleration/deceleration and A/C compressor
switching.

Diagnosis Process:

Connector: B-101 1. Check the ignition spark. If abnormal,

check the ignition circuit. If normal, go to
next step.

2. Check the injector connector of misfire

cylinder.

If abnormal, repair or replace it. If nor-

mal, go to next step.
Harness side connector
3. Check the misfire cylinder injector. If ab-
normal, replace it. If normal, go to next
step.

4. Check the engine relay connector G2X-

29 and ECU connector A47-23.

If abnormal, repair or replace it. If nor-

mal, go to next step.

Connector: B-15X Relay box’s 5. Check the harness between engine relay
triangle marks connector G2X-17 and misfire injector
connector (terminal 2#).

CAUTION
Should check the middle connector
Harness side ACJ05 before check the harness, replace
connector it if necessary.

• Check the damage for power cord

If abnormal, replace it. If normal, go to

next step.

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Connector: B-101 6. Check the harness between misfire cyl-

inder injector connector (terminal 1#)
and ECU connector A46.

• Check the damage for output wire

If abnormal, repair it. If normal, go to

next step.

7. Fuel pressure test. If abnormal, replace

Harness side connector
it. If normal, go to next step.

8. Read the MUT-III DTC.

If the DTC occurs, replace ECU. If no

DTC, intermittent defect.

DTC U0001/0146: CAN communication failure

CAUTION
Make sure the communication of computer is normal.

Check Conditions Most Likely Causes

• At any time • The bus harness or connector failed
• ECU failed

Diagnosis Process:

1. MUT-III bus diagnosis.

• Use the MUT-III to do bus diagno-

sis

If abnormal, repair it and go to step 3. If

normal, go to next step.

2. Read the MUT-III DTC.

• Be sure if the ECU has output DTC

1) Erase the DTC

2) Turn the ignition off and turn it on

again

3) Make if the DTC occurs

If the DTC occurs, replace ECU and go

to next step. If no DTC, intermittent de-
fect.

3. Read the MUT-III DTC.

• Make sure if the ECU outputs DTC

1) Erase the DTC

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 BYD S6, S6A, S6K Service Manual

2) Turn the ignition off and turn it on

again

3) Make if the DTC occurs

If the DTC occurs, go to step 1. if no

DTC, check ends.

U0415: ABS-ECU communication abnormal

CAUTION
Should make sure the communication of computer is normal after replaced the ECU.

JUDGEMENT CRITERION:

• Can not receive the signal from the ABS electronic control unit through the bus

Check Conditions Most Likely Causes

• Battery voltage ≥ 10V • Harness wire or connector failed

• The ignition switch is turned off or 3 seconds or • ECU failed

more passed between turned it on and off • ECU of ABS failed

Diagnosis Process:

1. MUT-III bus diagnosis.

• Use the MUT-III to do the bus diag-
nosis
If abnormal, repair it and go to step 6. If
normal, go to next step.

2. Read the DTC by using other system

function of MUT-III.
• Make sure if the ECU of ABS out-
puts DTC
If the DTC occurs, check and repair the
ABS system. If no DTC, go to next step.

3. Read the DTC by using other system

function of MUT-III.

1) EPS electronic control unit

2) Combination instrument panel

electronic control unit

If the DTC occurs, go to next step. If no

DTC, go to step 5.

4. Read the MUT-III DTC.

• Make sure if the ECU output the
DTC

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 BYD S6, S6A, S6K Service Manual

1) Erase the DTC

2) Turn the ignition switch off and turn

it on

3) Make if the DTC still occurs

If the DTC occurred, replace the ECU of

ABS and go to step 6.

If no DTC, intermittent defect.

5. Read the MUT-III DTC.

• Make sure if the DTC occurred

1) Erase the DTC

2) Turn the ignition switch off and turn

it on

3) Make sure if the DTC still output

If the DTC occurred, replace the ECU of

engine and go to step 6.

If no DTC, intermittent defect.

6. Read MUT-III DTC.

• Make sure if the ECU output DTC

1) Erase the DTC

2) Turn the ignition switch off and turn

it on

3) Make sure if the DTC still output

If the DTC occurred to step 1.If no DTC,

check is completed.

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4.2 Malfunction Symptom Inspection Procedures

Inspection Procedure 1: Communication with ECU Is Not Possible

COMMENT: A diagnostic output is made from the ECU (terminal A48-22#) to the diagnostic out-
put terminal (terminal 7#) of the data link connector.

Malfunction symptom Most Likely Causes

The ECU detects the malfunction, or the open/short 1. Power circuit of ECU is open or short circuit
diagnostic circuit will cause this malfunction.
2. The circuit between ECU and diagnostic
connector is short circuit
3. ECU failed

Diagnostic procedure:

1) Check the engine starting. If abnormal,

check the engine-ECU power, control
relay, ignition switch IG1.If normal, go to
next step.

2) Check the ECU connector, If abnormal,

repair or replace it. If normal, go to next
step.

3) Check CG26 (diagnostic connector ter-

minal 7#) and A48 (ECU terminal 7#). If
abnormal, repair it. If normal, go to next
step.

4) Check the malfunction symptom. If ab-

normal, replace ECU. If normal, intermit-
tent defect.

CAUTION
Should the connector Ac05 before check
the harness wire, if abnormal, repair it.

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Inspection Procedure 2: Ignition switch is to ON, the engine warning lamp does not illumi-
nate right

Malfunction symptom Most Likely Causes

The engine warning lamp will illuminate immediately 1. Bulb failed
for 5 seconds after the ignition switch is to ON posi-
2. Malfunction engine warning lamp circuit (short
tion.
or open circuit)
If the engine warning lamp does not illuminate, the
malfunction may as the right table

Diagnostic procedure:

1. Use the MUT-III to read the DTC. If the DTC occurred, refer to DTC procedure. If no DTC, go
to next step.

2. Check the malfunction symptom, if the malfunction continual exist, replace the instrument
panel assy.. if not continual, intermittent defect.

Inspection Procedure 3: Engine warning lamp never goes out

Malfunction symptom Most Likely Causes

May be the engine-ECU detects one sensor or ex- Short instrument panel circuit
ecuter failed, or as the right list.

Diagnostic procedure:

1. Use the MUT-III to read DTC. If the DTC occurred, refer to DTC procedure. If no DTC, go to
next step.

2. Check the malfunction symptom, if it continual exist, replace the instrument panel. If not con-
tinual, that is intermittent defect.

Inspection Procedure 4: Engine won’t start

Malfunction symptom Most Likely Causes

Ignition circuit fails fuel supply fails or other reasons. • Battery failed
• Timing belt cracked
• Throttle dirty
• Malfunction of ignition system
• Malfunction of fuel system
• Malfunction of limit switch
• Engine ECU failed

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Diagnostic procedure:

Connector: C-307 1. Check the battery voltage: Measure

<L.H. drive vehicles> while starting Standard value: ≥ 8V, If
abnormal, check the battery (refer to in-
spection procedure of battery). If normal,
go to next step.

2. Communication with MUT-II. Make sure

the normal communication between
MUT-III and engine ECU. If normal, go
to next step, If abnormal, check engine
<R.H. drive vehicles> ECU power supply, control relay and
ignition switch IG1 system. (refer to in-
spection procedure 22).

3. MUT-IIIDTC. If the DTC occurred, refet

to DTC of inspection procedure, if no
DTC, go to next step.

Harness side connector

4. MUT-III executer function test.
Standard value: Can hear the running
sound of fuel pump

If abnormal, check the fuel pump system

(refer to inspection procedure 23). If nor-
mal, go to next step.

5. Check the damage extent of timing belt.

Engine: Running Standard value:

Camshaft rotating

If abnormal, replace timing belt. If nor-

mal, go to next step.

6. Check the dirty of throttle body (a part of

throttle valve).

If abnormal, clean the throttle body. If

normal, go to next step.

7. MUT-III data list inspection.

If abnormal, go to step 8 (manual) or

step 9 (auto). If normal, go to step 10.

8. Engine ECU connector.

If abnormal, repair or replace it. If nor-

mal, check the middle connector The
same as step 8

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 BYD S6, S6A, S6K Service Manual

Connector: C-307 9. MUT-III data stream inspection. Refer to

<L.H. drive vehicles> item 22 of data list A: Crankshaft angle
sensor. If abnormal, check the crank-
shaft angle sensor. If normal, go to next
step.

10. Check the work sound of injector. If ab-

normal, check the injector of malfunction
cylinder. If normal, go to next step.

11. Check the ignition coils. If abnormal,

<R.H. drive vehicles>
check the ignition circuit system. If nor-
mal, go to next step.

12. Fuel pressure test. If abnormal, repair it.

If normal, go to next step.

13. Replace the engine ECU.

Harness side connector Check the malfunction symptom again
after replaced the ECU. Malfunction dis-
appearance, check ends. Malfunction
continual, check if there is water or other
impurity in the fuel.

Inspection Procedure 5: Can not start (can ignition, can not start the engine) ; can not start
(start use long time)

Malfunction symptom Most Likely Causes

In cases such as the above, the cause is usually • Malfunction of the battery
either weak spark, improper air-fuel mixture or low
• Malfunction of the ignition system
compression.
• Malfunction of the fuel system
• Malfunction of air-fuel control system
• Malfunction of the intake system
• Malfunction of the EGR system
• Throttle dirty
• Timing belt dislocation
• Malfunction of injection
• Low compression
• ECU failed

Diagnostic procedure:

1. Check the battery. If normal, run at idle speed 10 minutes after warmed engine up. If abnor-
mal, go to next step.

2. Check the battery voltage. Standard value: ≥ 8V If abnormal, check the battery. If normal,
go to next step.

3. MUT-III DTC. If the DTC occurred, refer to the inspection procedure of DTC. If no DTC, go to next step.

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 BYD S6, S6A, S6K Service Manual

4. MUT-III data stream inspection. Refer to the data list.

5. If abnormal, check the abnormal sensor.

6. If normal, go to next step.

7. MUT-III data stream inspection. Item 25: air pressure sensor If abnormal, replace it. If nor-
mal, go to next step.

8. Check the dirty of throttle body. If abnormal, clean the throttle body. If normal, go to next
step.

MUT-III executer test. Item 07: fuel pump Standard: can heat the action voice If abnor-
mal, check the fuel pump system. If normal, go to next step.

9. Check the intake air condition of intake pipe and intake manifold. If abnormal, repair it. If nor-
mal, go to next step.

10. Check the action voice of injector. If abnormal, check the malfunction injector. If normal, go to
next step.

11. Check the timing mark of timing belt. If abnormal, adjust the timing mark. If normal, go to
next step.

12. Check the ignition coils. If abnormal, check the ignition circuit (refer to the inspection proce-
dure 26). If normal, go to next step.

13. Check the injector atomizing condition. If abnormal, repair the injector. If normal, go to next
step.

14. Check the fuel pressure. If abnormal, repair it. If normal, go to next step.

15. Check the EGR solenoid valve(step motor). If abnormal, replace it. If normal, go to next step.

16. Replace the engine ECU. Check the malfunction symptom again after replaced it. Malfunc-
tion disappears, inspection ends. Malfunction continual, check if there is water or other impu-
rity in the fuel.

Inspection Procedure 6: Unstable idle, high idle or low idle, go out at idle.

Malfunction symptom Most Likely Causes

May be the ignition system, air-fuel ratio, ISC step • Malfunction of the ignition system
motor failed, or the low compressure. Should check
• Malfunction of the fuel system
the simple item first because of so many causes.
• Malfunction of the throttle valve control system
• Malfunction of the air-fuel ratio control system
• Malfunction of the intake/exhaust system
• The dirty of throttle body
• Dislocation of the timing belt
• Improper pressure
• Malfunction of engine ECU
• Malfunction of EGR control system

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 BYD S6, S6A, S6K Service Manual

Diagnostic procedure:

1. Battery inspection. If have disconnected

the battery terminal, after warming up
the engine run at idle speed 10 minutes.

If do not disconnect, go to next step.

2. Use MUT-III “self-diagnosis” function to

detect if the DTC occurs. If the DTC oc-
curred, refer to the DTC inspection pro-
cedure. If no DTC, go to next step.

3. MUT-III data stream inspection.

Refer to the data list.

If abnormal, check the abnormal sen-

sors.

If normal, go to next step.

4. MUT-III data stream inspection. Item 25:

Air pressure sensor If abnormal, replace
the ECU. If normal, go to next step.

5. Check the air flow of intake pipe and

intake manifold. If abnormal, repair it. If
normal, go to next step.

6. Check the timing mark of timing belt. If

abnormal, adjust the timing mark. If nor-
mal, go to next step.

7. Check the dirty of throttle body. If abnor-

mal, clean the throttle body. If normal, go
to next step.

8. MUT-III data stream inspection.

If abnormal, check the abnormal sensors.

If normal, go to next step.

9. Check the voltage of engine ECU con-

nector C-111.
• Measure the ECU terminal voltage
• Engine: Idle after warm up
• Transmission: N or P
• Radiator fan: Stop
• Measure the voltage between ter-
minal 45# and the ground terminal
Standard: The headlamp is turned off
to on, the voltage will increase.

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BYD S6, S6A, S6K Service Manual

If normal, go to step 13. If abnormal, go

to next step.

10. Check the engine ECU connector C-111

and engine connector B-119. If abnor-
mal, repair or replace it. If normal, go to
next step.

11. Check the harness wire between ECU

connector C-111 (terminal 45#) and gen-
erator connector B-119 (terminal 1#).

CAUTION
Should check the middle connector B-17
before check the harness wire.

If abnormal, repair it. If normal, replace

the generator, and go to next step.

12. Check the malfunction symptom. If the

malfunction disappears, check ends. If
malfunction continual, replace the en-
gine ECU.

13. Check the spark plug. If abnormal, re-

place it. If normal, go to next step.

14. Check the ignition coil. If abnormal,

check the ignition circuit system (refer to
inspection procedure 26 of ignition sys-
tem). If normal, go to next step.

15. Check the EGR valve. If abnormal, re-

place it. If normal, go to next step.

16. Check the EGR solenoid valve (step mo-

tor). If abnormal, replace it. If normal, go
to next step.

17. Check the atomization conditions of in-

jector. Check the atomization conditions
of each injector. If abnormal, replace it. If
normal, go to next step.

18. Check the fuel pressure. If abnormal, re-

pair it. If normal, go to next step.

19. Replace the engine ECU. Check the

malfunction symptom again after re-
placed. If the malfunction disappears,
check ends. If the malfunction continual,
check if there are water or other impurity
in the fuel.

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 BYD S6, S6A, S6K Service Manual

Inspection Procedure 7: Starts up and dies

Malfunction symptom Most Likely Causes

Maybe the weak spark plug cause no ignition, or the • Malfunction of the ignition switch
incorrect air-fuel ratio when step the accelerator.
• Malfunction of the intake system
• Malfunction of the oil gas evaporating system
• Malfunction of the engine ECU

Diagnostic procedure:

1. Use the MUT-III to read the DTC. If the DTC occurred, refer to the DTC inspection proce-
dure. If no DTC, go to next step.

2. MUT-III data stream test. Refer to data stream test table:

If abnormal, check the abnormal sensor. If normal, go to next step.

3. Check the EGR solenoid valve (step motor). If abnormal, replace it. If normal, go to next
step.

4. Check the intake air state of the intake pipe and intake manifold. If abnormal, repair it. If nor-
mal, go to next step.

5. Check the spark plug. If abnormal, replace it. If normal, go to next step.

6. Check the spark coils. If abnormal, check the ignition circuit system. If normal, replace the
ECU.

Inspection Procedure 8: Speeds up and dies

Malfunction symptom Most Likely Causes

Poor intake air, defective EGR system cause the in- • Malfunction of the throttle valve control system
correct air fuel ratio.etc.
• Malfunction of the ignition system
• Malfunction of the fuel/air evaporation system
• Smudginess of the throttle body
• Malfunction of the engine ECU

Diagnostic procedure:

1. Using the MUT-III to read the DTC. If the DTC occurred, refer to the DTC procedure. If no
DTC, go to next step.

2. MUT-III data stream test. Refer to data stream test table:

If abnormal, check the abnormal sensors. If normal, go to next step.

3. Check the EGR solenoid valve (step motor). If abnormal, replace it. If normal, go to next step.

4. Check the smudginess of the throttle body. If abnormal, clean the throttle body. If normal, go
to next step.

5. Check the spark plug. If abnormal, replace it. If normal, go to next step.
6. Check the spark plug. If abnormal, check the ignition circuit system. If normal, replace the
ECU.

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Inspection Procedure 9: Poor acceleration

Malfunction symptom Most Likely Causes

Detective of the fuel system, throttle valve control • Malfunction of the ignition system
system, ignition system is suspected.
• Malfunction of the fuel system
• Malfunction of the throttle valve control system
• Malfunction of the engine ECU

Diagnostic procedure:

1. Using the MUT-III to read DTC. If the DTC occurred, refer to the DTC procedure. If no DTC,
go to next step.

2. MUT-III data stream test. Refer to data stream test table:

If abnormal, check the abnormal sensor. If normal, go to next step.

3. Check the ignition coil. If abnormal, check the ignition circuit system (refer to the inspection
procedure 26). If normal, go to next step.

4. Check the timing mark of timing belt. If abnormal, adjust the timing mark. If normal, go to
next step.

5. Check the spark plug. If abnormal, replace it. If normal, go to next step.

6. Fuel pressure measurement. If abnormal, repair it. If normal, replace the engine ECU.

Inspection Procedure 10: Hesitation, Sag or Stumble

Malfunction symptom Most Likely Causes

Maybe caused by badness of ignition system, air • Malfunction of the air fuel ratio control system
fuel ratio, throttle valve control system.
• Malfunction of the ignition system
• Malfunction of the fuel supply system
• Malfunction of the intake/exhaust system
• Malfunction of the fuel-air evaporation system
• Malfunction of the throttle valve control system
• Badness of the compression
• Malfunction of the engine ECU

Diagnostic procedure:

1. Using the MUT-III to read the DTC. If the DTC occurred, refer to the DTC procedure. If no
DTC, go to next step.

2. Check the action sound of injector. If abnormal, check the injector of failed cylinder. If normal,
go to next step.

3. MUT-III data stream test. Refer to data stream test table:

If abnormal, check the abnormal sensor. If normal, go to next step.

4. MUT-III DATA STREAM INSPECTION. Item 25: air pressure sensor If abnormal, replace the
ECU. If normal, go to next step.

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 BYD S6, S6A, S6K Service Manual

5. Check the carbon tank control solenoid valve. If abnormal, replace it. If normal, go to next
step.

6. Check the EGR solenoid valve (step motor). If abnormal, replace it. If normal, go to next
step.

7. MUT-III data stream inspection.

If abnormal, check the abnormal sensors. If normal, go to next step.

8. Check the spark plug. If abnormal, replace it. If normal, go to next step.

9. Check the ignition coil. If abnormal, check the ignition circuit system (refer to the inspection
procedure 26). If normal, go to next step.

10. Check the smudginess of throttle body. If abnormal, clean the throttle body. If normal, go to
next step.

11. Measure the fuel pressure. If abnormal, repair it. If normal, go to next step.

12. Check the compression. If abnormal, repair it. If normal, replace the engine ECU.

Inspection Procedure 11: Impact or shock while acceleration

Malfunction symptom Most Likely Causes

Maybe the current leakage or throttle valve control • Malfunction of the ignition system
system failed along with the request voltage of spark
• Malfunction of the throttle valve control system
plug increase when accelerating.
• Smudginess of the throttle body
• Malfunction of the engine ECU

Diagnostic procedure:

1. Using the MUT-III to read the DTC. If the DTC occurred, refer to the DTC procedure. If no
DTC, go to next step.

2. Make the MUT-III data steam inspection. Refer to the data list

If abnormal, check the abnormal sensor. If normal, go to next step.

3. Check the smudginess of throttle body. If abnormal, clean the throttle body. If normal, go to
next step.

4. Check the speak plug. If abnormal, replace it. If normal, go to next step.

5. Check the ignition coil. If abnormal, check the ignition circuit system (refer to the inspection
procedure 26. If normal, replace the engine ECU.

Inspection Procedure 12: Impact or shock while deceleration

Malfunction symptom Most Likely Causes

Maybe the malfunction of throttle valve control sys- • Malfunction of the throttle valve control system
tem the poor intake air
• Smudginess of the throttle body
• Malfunction of the engine ECU

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Diagnostic procedure:

1. Using the MUT-III to read the DTC. If the DTC occurred, refer to the DTC procedure. If no
DTC, go to next step.

2. Make the MUT-III DATA STREAM INSPECTION. Refer to the data list

If abnormal, check the abnormal sensors. If normal, go to next step.

3. Check the smudginess of the throttle body. If abnormal, clean the throttle body. If normal, re-
place the ECU.

4. Check the spark plug. If abnormal, replace it. If normal, go to next step.

5. Check the spark coil. If abnormal, check the ignition circuit system (refer to the inspection
procedure 26). If normal, replace the engine ECU.

Inspection Procedure 13: Knocking

Malfunction symptom Most Likely Causes

In cases such as the above, the cause is probably • Malfunction of the knock senor
that the detonation control is defective or the
• Malfunction of the detonation control system
heat value of the spark plug is inappropriate.
• Malfunction of the ignition system
• Heat value of the spark plug inappropriate
• Malfunction of the engine ECU

Diagnostic procedure:

1. Using the MUT-III to read the DTC. If the DTC occurred, refer to the DTC procedure. If no
DTC, go to next step.

2. Check the spark plug. If abnormal, replace it. If normal, go to next step.

3. Check the ignition coil. If abnormal, check the ignition circuit system (refer to the inspection
procedure 26). If normal, check the knock sensor.

Inspection Procedure 14: Ignition timing offsetting

Malfunction symptom Most Likely Causes

Defective of the crankshaft angle sensor, camshaft • Malfunction of the crankshaft angle sensor
position sensor or timing belt etc. are suspected.
• Malfunction of the camshaft position sensor
• The defective position of the timing belt
• Malfunction of the engine ECU

Diagnostic procedure:

1. Using the MUT-III to read the DTC. If the DTC occurred, refer to the DTC procedure. If no
DTC, go to next step.

2. Measure the output waveform of the crankshaft angle sensor and camshaft position sensor
(use oscillograph).

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Connector: B-121 Crankshaft angle sensor

Use special test line MB991658 to connect

the crankshaft angle sensor middle connector
Ab22-2, measure the waveform.
Ab22 (GR)
• Engine: Idle

• Transmission: N or P
Harness side
connector • Measure the voltage between terminal
2# and the ground

Connector: B-114 Camshaft position sensor

Use special test line MB991709 to connect

the camshaft position sensor connector Ab05-
Ab05-2(B)
2, measure the waveform.

• Engine: Idle

Harness side
• Transmission: N or P
connector
• Measure the voltage between terminal
2# and the ground

Standard: The output waveform of both

sensors should in-phase

If normal, go to step 3, If abnormal, go to step 4.

3. Check the malfunction symptom. If the malfunction still exists, replace the engine ECU. If the
malfunction disappears, that is intermittent defect.

4. Check the mounted of the crankshaft angle sensor and camshaft position sensor. If abnor-
mal, repair it. If normal, go to next step.

5. Check the timing mark of the timing belt. If abnormal, adjust the timing mark. If normal, go to
next step.

6. Check the crankshaft sensing blead.If abnormal, replace it. If normal, go to next step.

7. Check the camshaft sensing blead. If abnormal, replace it. If normal, go to next step.

8. Replace a new crankshaft angle sensor. Check the malfunction symptom again after re-
placed. If the malfunction disappears, check ends. If the malfunction still exists, go to next
step.

9. Replace the camshaft position sensor. Check the malfunction symptom again after replaced,
if the malfunction disappear, that is intermittent defect. If the malfunction still exists, replace
the ECU.

Inspection Procedure 15: Afterburning

Malfunction symptom Most Likely Causes

Maybe the leakage injector • Malfunction of the injector
• Malfunction of the engine ECU

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Diagnostic procedure:

Check the atomization status of injector. Check the atomization status of each injector. If abnor-
mal, replace the injector. If normal, replace the engine ECU.

Inspection Procedure 16: Exhaust smell bad, white or black smoke, too high CO or HC
concentration while idling

Malfunction symptom Most Likely Causes

Abnormal air fuel ratio, defective Catalytic Converter, • Malfunction of the air fuel ratio control system
malfunction of the ignition etc.are suspected.
• Malfunction of the ignition system
• Malfunction of the fuel system
• Malfunction of the intake/exhaust system
• Malfunction of the fuel evaporation system
• Improper compression pressure
• Malfunction of the catalytic converter
• Malfunction of the engine ECU

Diagnostic procedure:

1. MUT-III DTC. If the DTC occurred, refer to the DTC procedure. If no DTC, go to next step.

2. Check the action sound of the injector. If abnormal, check the injector of the failed cylinder. If
normal, go to next step.

3. Check the ignition timing. If abnormal, check the offsetting ignition timing (refer to the inspec-
tion procedure 16). If normal, go to next step.

4. MUT-III DATA STREAM INSPECTION. Refer to the data list.

If abnormal, check the abnormal sensors. If normal, go to next step.

5. MUT-III DATA STREAM INSPECTION. Item 25: Air pressure sensor If abnormal, replace the
ECU.If normal, go to next step.

6. Check the intake air of the intake pipe and intake manifold. If abnormal, repair it. If normal,
go to next step.

7. Check fuel gas leak of the exhaust manifold. If abnormal, repair it. If normal, go to next step.

8. Check the smudginess of the throttle body. If abnormal, clean the throttle body. If normal, go
to next step.

9. MUT-III DATA STREAM INSPECTION.

If abnormal, check the abnormal sensors. If normal, go to next step.

10. Check the carbon tank control solenoid valve. If abnormal, replace it. If normal, go to next
step.

11. Check the EGR solenoid valve (step motor). If abnormal, replace it. If normal, go to next
step.

12. Check the fuel pressure. If abnormal, repair it. If normal, go to next step.

13. Check the PCV valve. If abnormal, replace it. If normal, go to next step.

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 BYD S6, S6A, S6K Service Manual

14. Check the spark plug. If abnormal, replace it. If normal, go to next step.

15. Check the ignition coil. If abnormal, check the ignition circuit system (refer to the inspection
procedure 26). If normal, go to next step.

16. Check the compression pressure. If abnormal, repair it. If normal, go to next step.

17. Check the atomization of the injector. If abnormal, replace the injector. If normal, go to next
step.

18. Replace the catalytic converter. Check the malfunction symptom again after replaced. If the
malfunction disappeared, check ends. If the malfunction still exist, replace the engine ECU.

Inspection Procedure 17: Battery leakage

Malfunction symptom Most Likely Causes

Maybe the defective generator, or defective control • Malfunction of the battery
circuit etc..
• Short generator terminal G circuit
• Malfunction of the generator
• Malfunction of the engine ECU

Diagnostic procedure:

Connector: C-307 1. Check the battery voltage. Standard

<L.H. drive vehicles> value ≥ 8V

If abnormal, check the battery. If normal,

go to next step.

2. Check the generator connector Ab25-3.

If abnormal, repair it. If normal, go to

next step.

3. Measure the output voltage of the gen-

erator connector Ab25-3.
<R.H. drive vehicles>
• Remove the connector, measure
the harness side

• Measure the voltage between ter-

minal 3# and the ground terminal
Standard value: System voltage

If normal, go to step 5. If abnormal, go to

Harness side connector
next step.

• Check the short or open circuit for

the power cord

If abnormal, repair or replace it.

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Connector: AC10 4. Connector inspection: Engine ECU con-

nector.

If abnormal, repair or replace it. If nor-

mal, go to next step.

5. Check the control voltage of the engine

ECU connector.

• Remove the connector, measure

Harness side connector
the harness side

• Measure the voltage between ter-

minal A47-20# and the ground ter-
minal
Standard value: System voltage

If normal, go to step 8. If abnormal, go to

next step.

6. Check the harness wire between ECU

connector A47-20 (terminal 45#) and
generator connector Ab25 (terminal 4#).

• Check the short or open circuit for

output line

If normal, replace the generator. If ab-

normal, repair it.

7. Check the control voltage of the engine

ECU connector A47.

• Measure the terminal voltage of

ECU

• Engine: Idling after warming up

• Transmission: N or P

• Radiator fan: Stop

• Measure the terminal 20# and the

ground terminal
Standard: The voltage will increase
with turn the headlamp switch from
OFF to ON.

If abnormal, replace the generator. If

normal, go to next step.

8. Check the malfunction symptom. If the

malfunction disappears, that is intermit-
tent defect. If the malfunction continual,
replace the engine ECU.

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Inspection Procedure 18: Overheating

Malfunction symptom Most Likely Causes

Defective engine cooling system, fan controller, wa- • Lack or defective engine cooling water
ter temperature sensor etc.are suspected.
• Malfunction of the fan controller
• Malfunction of the water temperature
• Malfunction of the thermostat
• Malfunction of the water pump
• Malfunction of the radiator
• Malfunction of the engine ECU

Diagnostic procedure:

1. MUT-III DTC. If the DTC occurred, refer to the DTC inspection procedure. If no DTC, go to
next step.

2. Check the engine cooling water. If abnormal, replace or add cooling water. If normal, go to
next step.

CAUTION
If the over low surface of the cooling water, check the leakage position.

3. MUT-III executer.

Item 21: Fan controller Standard: The fan motor running

If abnormal, check the fan controller relay system (refer to inspection procedure 24). If nor-
mal, go to next step.

4. MUT-III DATA STREAM INSPECTION. Refer to data list. Item 21: Engine water temperature
sensor
Standard value: Cooling: Atmosphere temperature (air temperature)

Warming: 80 - 110°C

If abnormal, check the water temperature sensor system. If normal, go to next step.

5. Check the thermostat. If abnormal, replace the thermostat. If normal, go to next step.

6. Check the water pump. If abnormal, replace the water pump. If normal, replace the radiator.

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Inspection Procedure 19: Fan abnormal running

Fan controller circuit

COMMENT:

Engine ECU (terminal 17# or terminal 9#) outputs one control signal to fan controller.

Malfunction symptom Most Likely Causes

Engine-ECU outputs one load signal to fan control- • Malfunction of the fan controller
ler based on the engine coolant temperature, speed
• Open or short circuit of the fan controller circuit
and air conditioner switch position, according to this
and connector
signal, fan controller control radiator fan, A/C con-
densator fan (the more closed to 5 volts average • Malfunction of the engine-ECU
voltage of the terminal, the more high speed of fan).

Diagnostic procedure:

Connector: A-26 1. Check the engine ECU connector A46. If

abnormal, repair or replace it. If normal,
go to next step.

2. Check the engine ECU connector C A46.

• Remove the connector, measure

the harness side
Harness side connector
• Ground the terminal 17# and the
grounding terminal
Standard: Fan motor stopped

If do not stop, go to step 4. if stopped,

go to next step.

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Connector: A-26 3. Check the malfunction symptom. If the

malfunction disappear, that is intermit-
tent defect. If the malfunction continual,
replace the engine ECU.

Measure the control voltage of the en-

gine ECU connector A46.
Harness side connector
• Remove the connector, measure
the harness side

• Measure the voltage between ter-

minal 17# and the grounding termi-
nal
Standard value: 4.9 - 5.1 V

If normal, replace the fan control motor.

If abnormal, go to next step.

4. Check the fan controller connector c22.

If abnormal, repair or replace it. If nor-
mal, go to next step

5. Check the harness wire between engine

ECU connector A46 (terminal 17#) and
fan controller connector C22 (terminal
2#).

CAUTION
Check the connector A-16 before check
the harness wire, if failed, repair it.

• Check the open circuit for output

wire

If normal, replace the fan controller..If

abnormal, repair it.

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Inspection Procedure 20: Fuel pump system

Accumulator Main relay

Fuel bump
Fuel pump
motor

Fuel pump motor

CIRCUIT OPERATION:

• Battery voltage is applied to the fuel pump relay 1 (terminal 86#) from accumulator ,to ECM
from fuel bump relay 1 (terminal 85#).

• Battery voltage is applied to the fuel pump relay 1 (terminal 88a#) and the fuel pump relay
2(terminal 4#) from the fuel pump relay (1) terminal 88 # .

Malfunction symptom Most Likely Causes

When the engine is started or running, the ECU con- • Malfunction of fuel pump relay
trol the relay to ON, make the voltage provided to
• Malfunction fuel pump
fuel pump.
• Improper connector contact, open or short
circuited harness wire.
• Malfunction of the ECU

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Diagnostic procedure:

Connectors: C-214, C-216

1. Check the fuel pump relay connector. If
<L.H. drive vehicles> abnormal, repair or replace it. If normal,
go to next step.

2. Check the fuel pump relay. If abnormal,

replace it. If normal, go to next step.

Relay box’x 3. Check fuses F2/24. If normal, go to next

triangle marks step.

4. Check the voltage at the fuel pump con-

<R.H. drive vehicles> trol relay.

Harness side • Remove the relay.

connector
• Ignition switch: ON

• Check the voltage between ter-

minal 88#. terminal 88# and the
ground harness wire
Standard value: System voltage

If abnormal, replace MCU; If normal, go

to next step.

5. Check the engine ECU connector A 46.

• Remove the connector, measure

wire harness side..

• Start the engine.

• Check the voltage between termi-

nal 10#. and the ground .
Standard value: <1 voltage

If abnormal, check the middle connector;

IF the malfunction exists, repair it. If no
malfunction, check and repair the wire
harness between the fuel bump control
relay connector.

• Check the ground corn open or

short circuit.

If normal, go to next step.

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 BYD S6, S6A, S6K Service Manual

Connector: D-15 6. Check fuel pump connector K15.If ab-

normal, repair or replace it. If normal, go
to next step;
Harness side
connector 7. Measure the positive voltage at the fuel
pump connector K15.

• Remove connector, measure har-

ness side.

• Ignition switch: ON

• Measure the voltage between ter-

minal 4# and the ground.
Standard value: System voltage

If normal, go to step 9.If abnormal, go to

next step.

Connector: C-214 8. Check the harness between fuel bump

<L.H. drive vehicles> control relay connector 88a and fuel
bump connector K15 (terminal 4#).

CAUTION
Before checking harness, check the mid-
Relay box’s dle connector.
triangle marks

• Check the power cord for open cir-

cuit or damage
<R.H. drive vehicles>
If abnormal, repair or replace it
Harness side
connector

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Inspection Procedure 21: Fan control relay system

Refer to air- conditioning system

Inspection Procedure 22: A/C compressor relay system

Refer to air- conditioning system

Inspection Procedure 23: Ignition circuit system

IG1 electricity

Ignition
coil
15A
Ignition coil

Ignition coin

Ignition coin

Ignition coin

1# 2# 3# 4#
Igniting Igniting Igniting Igniting
coin coin coin coin

Malfunction symptom Most Likely Causes

Engine ECU turns the power transistor of ignition • Malfunction of the ignition coil
coil ON or OFF to cut off the primary current of igni-
• Malfunction of the spark plug
tion coil.
• Poor connector contact, open or short wiring
circuit
• Malfunction of the engine ECU

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 BYD S6, S6A, S6K Service Manual

Diagnostic procedure:

Connectors: B-02, B-03, B-04, B-05 1. Check the spark plug. If abnormal, re-
place it. If normal, go to next step.

2. Check the ignition coil connector A08,

A19, A34 and A35.

If abnormal, repair or replace it. If nor-

mal, go to next step.

3. Check the ignition coil. If abnormal, re-

Harness side connector
place it. If normal, go to next step.

4. Measure the operation of ignition coil

connector A08, A19, A34 和 A35.

• Remove the connector, measure

the harness side

• Ignition switch: ON

• Measure the voltage between ter-

minal 3# and the ground
Standard value: System voltage

If normal, go to step 6. If abnormal, go to

next step.

5. Measure the operation voltage of the ig-

nition coil connector A08, A19, A34 and
A35.If normal.

1) Remove the connector, measure

harness side.

2) Engine: Running

3) The voltage between 2# and, the

ground.
Standard value: 0.1 - 0.2 V

If normal, go to step 10; If abnormal, go

to next step.

6. Check the engine ECU connector A47.If

abnormal, repair or replace it; If normal,
go to next step.

7. Check the operation voltage of ECU

connector A47.
• Measure ECU terminal voltage
• Remove ignition coin connector
A08, A19, A34 and A35
• Engine: Running

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 BYD S6, S6A, S6K Service Manual

Connectors: B-02, B-03, B-04, B-05 1) Measure the voltage between

terminal 4# and the ground
chassis (ignition coil 1#)

2) Measure the voltage between

terminal 3# and the ground
chassis (ignition coil 2#)

3) Measure the voltage between

Harness side connector terminal 13# and the ground
chassis (ignition coil 3#)

4) Measure the voltage between

terminal 28# and the ground
chassis (ignition coil 4#)
Standard value: 0.1 - 0.2 V

If normal, check and repair the harness

wire between engine ECU connector
and ignition coil connector.

1) Check and repair the harness wire

between 1# ignition coil connector
A19 (terminal 1#) and engine ECU
connector A47 (terminal 4#)

2) Check and repair the harness wire

between 2# ignition coil connector
A08 (terminal 1#) and engine ECU
connector A471(terminal 3#)

3) Check and repair the harness wire

between 3# ignition coil connector
A34 (terminal 1#) and engine ECU
connector A47 (terminal 13#)

4) Check and repair the harness wire

between 4# ignition coil connector
A35 (terminal 1#) and engine ECU
connector A47 (terminal 28#)

• Check the open circuit for out-

put wire

If abnormal, go to next step.

8. Check the harness wire between the

ignition coil connector and engine ECU
connector.

1) Check and repair the harness wire

between 1# ignition coil connector
A19 (terminal 1#) and engine ECU
connector A47 (terminal 4#)

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 BYD S6, S6A, S6K Service Manual

Connectors: B-02, B-03, B-04, B-05 2) Check the harness wire between
the 1# ignition coil connector A08
(terminal 1#) and engine ECU con-
nector A47 (terminal 3#).

3) Check the harness wire between

the 1# ignition coil connector A34
(terminal 3#) and engine ECU con-
nector A47 (terminal 13#).
Harness side connector
4) Check the harness wire between
the 1# ignition coil connector A35
(terminal 1#) and engine ECU con-
nector A47 (terminal 28#).

• Check the short circuit for out-

put wire

If abnormal, repair it. If normal, go to

next step.

9. Check the malfunction symptom. If the

malfunction continues replace the en-
gine ECU. It the symptom disappears,
that is intermittent defect.

Measure the operation voltage of ignition

coil connector A08, A19, A34 and A35.
• Remove the connector, mea-
sure the harness side
• Measure the resistance be-
tween terminal 2# and the
ground chassis
Standard value: ≤ 2 Ω

If normal, go to next step.

If abnormal, check and repair the har-

ness wire between the ignition coil con-
nector and the ground chassis.

5) Check and repair the harness wire

between the 1# ignition coil con-
nector A19 (terminal 2#) and the
ground chassis.

6) Check and repair the harness wire

between the 2# ignition coil con-
nector A08 (terminal 2#) and the
ground chassis.

7) Check and repair the harness wire

between the 3# ignition coil con-
nector A34 (terminal 2#) and the
ground chassis.

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 BYD S6, S6A, S6K Service Manual

Connectors: B-02, B-03, B-04, B-05 8) Check and repair the harness wire
between the 4# ignition coil con-
nector A35 (terminal 2#) and the
ground chassis.

• Check the open circuit and

damage for the ground wire

Harness side connector

Connector: C-307
10. Check the harness wire between the ig-
<L.H.drive vehicle> nition coil connector and the engine ECU
connector.

1) Check and repair the harness wire

between the 1# ignition coil con-
nector A19 (terminal 1#) and the
engine ECU connector A47 (termi-
nal 4#)

2) Check and repair the harness wire

between the 2# ignition coil con-
<R.H.drive vehicle> nector A08 (terminal 3#) and the
engine ECU connector A47 (termi-
nal 3#)

3) Check and repair the harness wire

between the 3# ignition coil con-
nector A34 (terminal 1#) and the
engine ECU connector A47 (termi-
nal 13#)
Harness side connector
4) Check and repair the harness wire
between the 4# ignition coil con-
Connectors: B-02, B-03, B-04, B-05 nector A35 (terminal 1#) and the
engine ECU connector A47 (termi-
nal 28#)

• Check the damage for output

wire

If abnormal, repair it. If normal, go to

next step.
Harness side connector

Inspection Procedure 24: Upstream Cylinder oxygen sensor heater system

CIRCUIT OPERATION:

• Engine control relay (terminal 85#) outputs the power to the heater power terminal (terminal
2#) of upstream cylinder oxygen sensor heater.

• The engines ECU (terminal 8#) monitor the power transistor to control the upstream cylinder
oxygen sensor heater (terminal 4#).

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 BYD S6, S6A, S6K Service Manual

Malfunction symptom Most Likely Causes

Turn the engine ECU power transistor ON/OFF to • Malfunction of the upstream oxygen sensor
control the power of upstream oxygen sensor heater. heater
• Poor connector contact, open or short wiring
circuit
• Malfunction of the engine ECU

Accumulator

EMS
Relay
15A

Main
relay
Front oxygen sensor

Shield
layer
Shield
layer

Diagnostic procedure:

Connector: B-15X Relay box’s 1. Check the upstream cylinder oxygen

triangle marks sensor connector A20.If abnormal, re-
place it. If normal, go to next step.

2. Measure the operation voltage of the up-

stream cylinder oxygen sensor connec-
tor A20.
Harness side
connector • Remove the connector, measure at
the side harness

• Measure the resistance between

terminal 2# and 4#
Standard value: 11 - 18 Ω

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 BYD S6, S6A, S6K Service Manual

Connector: B-26 If abnormal, replace it. If normal, go to

next step.

3. Measure the operation voltage of the up-

stream oxygen sensor connector A20.
Cylinder 1, 4 oxygen
sensor • Remove the connector, measure
the harness side

• Start

• Measure the voltage between ter-

minal 2# and the ground terminal
Standard value: System voltage

If normal, go to step 5. If abnormal, go to

next step.

4. Check the engine control connector

G2X-29. If abnormal, repair or replace it.

If normal, check the middle connector, if

Harness side failed, repair it. If no malfunction, check
connector and repair the harness wire between
upstream oxygen sensor connector A20
\(terminal 2#) and the engine control re-
lay connector G2X-29 (terminal 1#).

• Check the short or open circuit for

the power cord

5. Measure the operation voltage of the en-

gine ECU connector A46.

• Measure the terminal voltage of

ECU

• Start

• Voltage between terminal 4# and

the ground terminal
Standard value: <1V

If normal, go to step 8. If abnormal, go to

next step.

6. Check the engine ECU connector A46. If

abnormal, repair or replace it. If normal,
go to next step.

7. Check the harness wire between up-

stream oxygen sensor connector A20
(terminal 4#) and the engine ECU con-
nector A46 (terminal 8#).

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 BYD S6, S6A, S6K Service Manual

Connector: B-26 • Check the open or short circuit for

the ground chassis wire

If normal, replace the engine ECU. If ab-

normal, repair it.
Cylinder 1, 4 oxygen
sensor 8. Check the engine ECU connector A46. If
abnormal, repair or replace it. If normal,
go to next step.

9. Check the harness wire between up-

stream cylinder oxygen sensor connec-
tor A20 (terminal 2#) and engine control
relay connector G2X-29.

CAUTION
Should check the middle connector be-
fore checking harness wire.

• Check the damage for the power

cord
Harness side
connector If abnormal, repair it. If normal, go to
next step.

10. Check the harness wire between up-

stream oxygen sensor connector A20
(terminal 4#) and the engine ECU con-
nector A46 (terminal 8#).

• Check the damage for the ground

wire

If abnormal, repair it. If normal, go to

next step.

11. Check the malfunction symptom. If the

malfunction still exists, replace the en-
gine ECU. If the malfunction disappears,
that is intermittent defect.

Inspection Procedure 23: downstream oxygen sensor heater system

CIRCUIT OPERATION:

• Engine control relay 88a outputs the power to the downstream oxygen sensor heater power
terminal (terminal 2#)

• The power transistor of engine ECU (terminal 16#) controls the downstream oxygen sensor
heater (terminal 4#).

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 BYD S6, S6A, S6K Service Manual

Malfunction symptom Most Likely Causes

Turn the power transistor of engine ECU ON/OFF • Malfunction of the downstream oxygen sensor
to control the heater power of downstream oxygen heater
sensor heater power.
• Poor connector contact, open or short wiring
circuit
• Malfunction of the engine ECU

Accumulator

EMS
Relay
15A
Main
relay
Rear oxygen sensor

Shield layer
Shield layer

Diagnostic procedure:

Connector: B-15X Relay box’s 1. Check the downstream oxygen sensor

triangle marks A06. If abnormal, repair or replace it. If
normal, go to next step.

2. Measure the operation resistance of the

downstream oxygen sensor connector
A06.
Harness side
connector • Remove the connector, measure at
the sensor side.

• Resistance between terminal 2#

and 4#
Standard value: 11 - 18 Ω

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Connector: B-25 If abnormal, replace it. If normal, go to

next step.

3. Measure the operation voltage of the

downstream oxygen sensor connector
A06.

• Remove the connector, measure

Cylinder 2, 3 oxygen the harness side
sensor
• Ignition switch: ON

• Voltage between terminal 1# and

the ground terminal
Standard value: System voltage

If normal, go to step 5. If abnormal, go to

next step.

4. Check the engine control connector

Harness side
connector G2X-29. If abnormal, repair or replace it.

If normal, check the middle connector. If

failed repair it. If no malfunction, check
and repair the harness wire between
downstream oxygen sensor connector
A06 (terminal 2#) and engine control re-
lay connector G2X-29.

• Check the open or short circuit for

the power cord

5. Measure the operation voltage of the en-

gine ECU connector A46.

• Measure the terminal voltage of

ECU

• Ignition switch: ON

• Measure the voltage between ter-

minal 116# and the ground terminal
Standard value: <1V

If normal, go to step 8. If abnormal, go to

next step.

6. Check the engine connector A46.

If abnormal, repair or replace it. If nor-

mal, go to next step.

7. Check the harness wire between 2, 3

cylinder oxygen sensor connector A06
(terminal 4#) and engine ECU connector
A46 (terminal 16#).

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Connector: B-25 • Check the open or short circuit for

the ground wire

If normal, replace the engine ECU. If ab-

normal, repair it.

8. Check the engine ECU connector A46.

Cylinder 2, 3 oxygen If abnormal, repair or replace it. If nor-

sensor mal, go to next step.

9. Check the harness wire between down-

stream oxygen sensor connector A06
(terminal 2#) and engine control relay
connector G2X-29.

CAUTION
Should check the middle connector be-
fore check the harness wire.
Harness side
connector • Check the damage for the power
cord

If abnormal, repair it. If normal, go to

next step.

10. Check the harness wire between 2, 3

cylinder oxygen sensor connector A06
(terminal 4#) and the engine ECU con-
nector A46 (terminal 16#).

• Check the damage for the ground

chassis wire

If abnormal, repair it. If normal, go to

next step.

11. Check the malfunction symptom. If the

malfunction still exists, replace the en-
gine ECU. If the malfunction disappears
that is intermittent defect.

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Inspection Procedure 24: EGR system

Accumulator

EMS
Relay
15A
Main
relay

ECR
valve

CIRCUIT OPERATION:

• Engine control relay (terminal 88a#) outputs the power to EGR valve (terminal 2# and termi-
nal 5#).

• Engine ECU (terminal 6#, 2#, 15#, 22#) turns the power crystal ON, the current through to
the EGR valve (terminal 1#, 3#, 4#, 6#).

Malfunction symptom Most Likely Causes

EGR controls the action rate of EGR according to • Malfunction of the solenoid valve
the engine ECU signal
• Bad harness contact, open or short circuit
• Malfunction of the engine ECU

Diagnostic procedure:

Connector: B-103 1. Check the EGR valve connector A39. If

abnormal, repair or replace it. If normal,
go to next step.

2. Check the EGR valve. If abnormal, re-

place it. If normal, go to next step.

3. Measure the execution voltage of EGR

connector A39.
Harness side connector

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• Remove the connector, measure

the harness side

• Start

• Measure the voltage between ter-

minal 2#, 5# and the ground termi-
nal
Standard value: System voltage

If normal, go to step 5. If abnormal, go to

next step.

Connector: B-15X Relay box’s 4. Check the engine control relay connec-
triangle marks tor G2X-29.

If abnormal, repair or replace it. If nor-

mal, check the middle connector, if
malfunction occurred, repair it, if no mal-
function, check and repair the harness
Harness side between engine control relay G2X-29
connector
and EGR valve connector A39 (terminal
2#, 5#).

• Check the open and short circuit

Connector: B-103
for the power cord

5. Measure the control voltage of engine

ECU connector A46.

Remove the connector, measure the

harness side

Start
Harness side connector
Measure the voltage between terminal
6#, 2#, 15#, 22# and the ground terminal
Standard value: System voltage

If normal, go to step 7.If abnormal, go to

next step.

6. Check the engine ECU connector A46.

If normal, Check the harness between

EGR valve connector A39 and engine
ECU connector A46

1) Check the harness between EGR

valve connector A39 (terminal 1#)
and engine ECU connector A46
(terminal 6#)

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Connector: B-15X Relay box’s 2) Check the harness between EGR

triangle marks valve connector A39 (terminal 3#)
and engine ECU connector A46
(terminal 2#)

3) Check the harness between EGR

valve connector A39 (terminal 4#)
Harness side and engine ECU connector A46
connector
(terminal 22#)

4) Check the harness between EGR

valve connector A39 (terminal 6#)
Connector: B-103
and engine ECU connector A46
(terminal 15#)

• Check the open and short circuit

for the power cord

If abnormal, repair or replace it.

7. Check the engine ECU connector A46. If

Harness side connector abnormal, repair or replace it. If normal,
go to next step.

8. Check the harness between EGR valve

connector A39 and engine ECU connec-
tor A46

1) Check the harness between EGR

valve connector A39 (terminal 1#)
and engine ECU connector A46
(terminal 6#).

2) Check the harness between EGR

valve connector A39 (terminal 3#)
and engine ECU connector A46
(terminal 2#).

3) Check the harness between EGR

valve connector A39 (terminal 4#)
and engine ECU connector A46
(terminal 22#).

4) Check the harness between EGR

valve connector A39 (terminal 6#)
and engine ECU connector A46
(terminal 15#).

• Check the damage for the output

wire

If abnormal, repair or replace it.

9. Check the harness between EGR valve

connector A39 (terminal 2#, 5#) and en-
gine control relay connector G2X-29.

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CAUTION
Should check the middle connector
C-116.

• Check the damage for power cord.

If normal, replace the engine ECU.
If abnormal, repair it.

Inspection Procedure 25: Canister control solenoid valve system

Accumulator

EMS
Relay
15A
Main
relay
Canister control valve

CIRCUIT OPERATION:

• Engine controls relay (terminal 88a #) outputs power to canister control solenoid valve (ter-
minal 1#).

• Engine ECU (terminal 25#) turns the power crystal ON, the current through to canister con-
trol solenoid valve (terminal 2#).

Malfunction symptom Most Likely Causes

The canister control solenoid valve controls the can- • Malfunction of the solenoid valve
ister flow air of input canister.
• Bad harness wire contact, open or short circuit
• Malfunction of the engine ECU

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Diagnostic procedure:

1. MUT-III executer test.

Item 08: Canister control solenoid valve

Standard: Should hear the action and
vacuum vibration sound

If normal, that is intermittent defect. If

abnormal, go to next step.

2. Check the canister control solenoid

valve connector A13.
Connector: B-15X Relay box’s
triangle marks If abnormal, repair or replace it. If nor-
mal, go to next step.

3. Measure the resistance of canister con-

trol solenoid valve connector A13.

• Disconnect the connector and

Harness side
connector measure the solenoid valve side
harness

• Measure the resistance between

terminal 1# and terminal 2#
Standard value: 30 - 34 Ω (at 20°C)

If abnormal, replace it. If normal, go to

next step.

4. Measure the positive voltage of canister

control solenoid valve connector A13.

• Remove the connector, measure

the harness side

• Start

• Measure the voltage between ter-

minal 1# and the ground wire
Standard value: System

If normal, go to step 6. If abnormal, go to

next step.

5. Check the engine control relay connec-

tor G2X-29.

If abnormal, repair or replace it. If nor-

mal, check the middle connector,. If
the malfunction occurred, repair it. If no
malfunction, check the harness between
purge control solenoid valve connector
A13 (terminal 2#) and engine control re-
lay connector G2X-29.

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• Check the open or short circuit for

power cord

6. Check the engine ECU connector A46.

If abnormal, repair or replace it. If nor-

mal, go to next step.

7. Measure the positive voltage of engine

ECU connector A46.

• Remove the connector, measure

Connector: B-15X Relay box’s the harness side
triangle marks
• Ignition switch: On

• Measure the terminal 25# and the

ground
Standard value: System
Harness side
connector
If normal, go to next step. If abnormal,
check and repair the harness between
the canister control solenoid valve con-
nector A13 (terminal 2#) and the engine
ECU connector A46 (terminal 25#).

• Check the open and short circuit

for output wire

8. Check the harness between canister

control solenoid valve connector A13
(terminal 2#) and the engine ECU con-
nector A46 (terminal 25#).

• Check the damage for output wire

If abnormal, repair it. If normal, go to

next step.

9. Check the harness between canister

control solenoid valve A13 (terminal1#)
and engine control relay connector G2X-
29.

CAUTION
Should check the middle connector C-116
before checking the harness.

• Check the damage for the power

cord

If abnormal, repair it. If normal, go to

next step.

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10. MUT-III executer test.

Item 08: canister control solenoid valve

Standard: should hear the action and
vacuum vibration sound

If normal, that is intermittent defect. If

abnormal, replace the engine ECU.

Inspection Procedure 26: Power steering hydraulic pressure switch system

Power steering switch

Malfunction symptom Most Likely Causes

The switch signal of power steering pump inputs to • Power steering solenoid valve failed
engine ECU.
• Improper circuit contact, open or short circuit
Engine ECU controls the idle speed according to this
• Engine ECU failed
signal.

Diagnostic procedure:

Connector: B-37 1. MUT-III data stream inspection. Refer to

the data list.

Item B4: Power steering hydraulic pres-

sure switch.

If normal, intermittent defect.

If abnormal, go to next step.

Harness side connector 2. Check power steering hydraulic pressure
switch connector AB07.

If abnormal, repair it. If normal, go to

next step.

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Connector: B-37 3. Check the harness wire between power

steering hydraulic pressure sensor con-
nector AB07 and engine ECU connector
A47(terminal 18#). If abnormal, repair
it. If normal, replace power steering hy-
draulic pressure switch.

• Check the power cord for damage

Harness side connector If abnormal, repair it. If normal, replace

steering hydraulic pressure switch.

Inspection Procedure 27: Oil control valve system

Accumulato

EMS
Relay
15A

Main
relay
Oil control valve

COMMENT:

• Engine control relay (terminal 88a#) output electrical source to oil control valve (terminal 2#).

• Engine ECU (terminal1#) turns ON the power crystal, the current through to oil control valve
(terminal 1#).

Malfunction symptom Most Likely Causes

Oil control valve make the MICEV at low or high • Malfunction of the oil control valve
speed by using camshaft, and keep consistent with
• Improper circuit contact, open or short circuit
the engine ECU signal.
• Enging ECU failed

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Diagnostic procedure:

Connector: B-07 1. Check the oil control valve connector

A38.If abnormal, repair or replace it. If
normal, go to next step.

2. Measure the positive voltage of the oil

control valve connector A38.

• Disconnect the connector, measure

the control valve side connector
Harness side connector • Measure the resistance between
terminal 1# and terminal 2#.
Standard value: 6.9 - 7.9 Ω (at 20°C)

If abnormal, replace it. If normal, go to

next step.

3. Measure the positive voltage of the oil

control valve connector A38.

• Remove the connector, measure

the harness side

• Power: ON

• Measure the voltage between ter-

minal 2# and the ground harness
wire
Standard value: System voltage

If normal, go to step 5. If abnormal, go to

next step.

Connector: B-15X Relay box’s 4. Check the engine control relay connec-
triangle marks tor G2X-29.

If normal, check the middle connector.

If the malfunction occurred, repair it. If
no malfunction, check and repair the
Harness side
harness wire between oil control valve
connector connector A38 (terminal 2#) and engine
control relay connector G2X-29.
Check the open or short circuit for
Connector: B-07 power cord

If abnormal, repair or replace it

5. Measure the positive voltage of engine

ECU connector A49.

• Remove the connector, measure

Harness side connector
the harness side

• Power: ON

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 BYD S6, S6A, S6K Service Manual

• Measure the voltage between ter-

minal 1# and the ground.
Standard value: System voltage

If normal, go to step 7.If abnormal, go to

next step.

6. Check the engine ECU connector A49.

If normal, check and repair the harness

wire between oil control valve connector
A38 terminal 1#) and engine ECU con-
nector A49 (terminal1#).

• Check the open or short circuit for

output wire

If abnormal, repair or replace it

7. Check the engine ECU connector A49. If

abnormal, repair or replace it. If normal,
go to next step.

8. Check the harness between oil control

valve connector A38 (terminal 1#) and
ECU connector A49 (terminal 1#).

• Check the output wire for damage

If abnormal, repair it. If normal, go to

next step.

Connector: B-15X Relay box’s 9. Check the engine control relay connec-
triangle marks tor B-15X. If abnormal, repair or replace
it. If normal, go to next step.

10. Check the harness wire between oil con-

trol valve connector A38 (terminal 2#)
Harness side
and engine control relay connector B-
connector 15X .

CAUTION
Should check the middle connector be-
fore check the harness wire

• Check the damage for power cord

If abnormal, repair it. If normal, go to

next step.

11. Check the malfunction symptom. If the

malfunction still exists, replace the en-
gine ECU. If the malfunction disappears,
that is intermittent defect.

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5. Ignition System
5.1 Summary

This system has four ignition coils with power transistor inside them, they separately act on every
cylinder. Cutting off the primary side current of ignition coil maybe generate high voltage at the
secondary side of ignition coil. The high voltage adds on the spark plug and generate spark. The
engine-ECU makes the two power transistors inside the ignition coils connect and disconnect al-
ternately. The result is that the primary current in the ignition coil is connected and disconnected
alternately, so ignite every cylinder according to the sequence of 1-3-4-2.

Engine-ECU uses the signals which are sent out from the cam position sensor and crankshaft
angle sensor to confirm the controlled ignition coil. It also tests crankshaft position, according to
this to provide ignition timing which is best suitable for engine running working condition. When
the engine is running in cold condition or under high altitude, the ignition timing is a little advanc-
ing to ensure the best performance under running working condition. Besides, when happening
the shock, the ignition timing is deferred greatly until the shock disappears.

System diagram

Ignition switch Battery jay

Air flow sensor
Ari pressure sensor
Intake temperature sensor
Water temperature sensor
Accelerator pedal position
sensor
Engine
Camshaft position sensor ECU
Crankshaft angle sensor
Ignition coil
Ignition switch-ST
Knock sensor
Speed sensor (MT)
Sto[ switch (AT)
Spark plug

Cylinder

Ignition coil specification

Item Specification
Ignition coil Moulding four coils

Spark plug clearance

Item Standard value Limit value

Clearance mm 0.7-0.8 1.2

Spark plug specification

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Item Specification
NGK LZFR6AI

Special tool

Tool No. Name Use

MD998773 Wrench of shock sen- Disassembly and assembly of shock sen-
sor sor

5.2 Inspection of Ignition Coil (Power transistor inside)

Conduction inspection of primary coil and

power transistor

NOTICE
• Use simulation type ohmmeter
• Connect the cathode (-) of multime-
ter to 1# end

NOTICE
This test should be completed rapidly (in
10 seconds).
To avoid burning the coil and damaging
the power transistor.

Connect and disconnect 4.5 - 9.0 V battery at

2# and 3#ends, observe the change of ohm-
meter finger whether it is continuous.

4.5 - 9.0 V Voltage Conduction be-

between 2 – 3 tween 1 – 2
When the current is circu-
Continuous
lating
When the current is not
Discontinuous
circulating

Inspection of secondary coil:

1. Disassemble the joint of ignition coil.

2. Disassemble ignition coil, install a new spark plug on ignition coil.

3. Check the joint of ignition coil.

4. The spark plug electrode side grounds start the engine.

5. Check the spark between spark plug electrodes.

6. If no spark is generated, replace a new ignition coil and check it.

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7. If using new spark plug can generate spark, replace old ignition coil. If no spark is still gener-
ated, check ignition circuit.

Inspection and cleanness of spark plug

1. Disassemble spark plug.

NOTICE
• Don not try to adjust center elec-
trode clearance of iridic gold.
• Cleaning with the tool should be
Iridic gold completed In 20 seconds. Do not
uses wire brush.

2. Check the clearance of spark plug, if it is

not in the range, replace it.
Standard range: 0.7 - 0.8 mm

limit value: 1.2 mm

NOTICE
Do not let the impurity into cylinder.

3. Clean the spark plug hole of engine.

4. Install spark plug.

Inspection of cam position sensor

According to repair manual of electronic fuel injection system—malfunction eliminating.

Inspection of crankshaft angle sensor

According to repair manual of electronic fuel injection system—malfunction eliminating.

Inspection of shock sensor

According to repair manual of electronic fuel injection system—malfunction eliminating.

Disassembly and assembly

Disassembly steps

1. Ignition coil joint

2. Ignition coil

3. Spark plug

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Disassembly and assembly

Disassembly steps

1. Joint of camshaft posi-

tion sensor

2. Camshaft position
sensor

3. O type ring

Disassembly and assembly

Disassembly step

1. Lower cover of timing

belt

2. Crankshaft position
sensor

Disassembly and assembly

NOTICE
Do not make the shock sensor fall down or impact any other parts, if the condition above
is happened, replace shock sensor.

Disassembly step

1. Shock sensor joint

2. Shock sensor clip

3. Wiring harness clip

4. Intake manifold cover

5. Shock sensor

6. Shock sensor clip

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6. Charging system
6.1 Summary

Charging system is the system that using the output energy of alternator to charge battery, and
make the battery keep the constant charging amount under different loads.

About 14.5V
Voltage

Time

Working principle

Rotation of motivated excitation coil in stator generates AC voltage. This AC current is commuted
into DC voltage by diode which has the waveform showing as the left picture. Average output volt-
age has small fluctuation under load condition of alternator.

When the ignition switch is putting through, the current inflows into excitation coil, the excitation
coil is initial motivated. When the stator is starting to generate power after the engine starts, the
excitation coil is motivated by output current of stator coil. If excitation current is increasing, the
output power of alternator increases; if the excitation current is decreasing, the output power de-
creases. When the battery voltage (S end’s voltage of alternator) is up to regulation voltage about
14.4V, excitation current is cut off. When the battery voltage is dropping down to lower than regu-
lation voltage, voltage regulator adjusts the output voltage through the method of controlling exci-
tation current, and make it keep constant level.

In addition, when the excitation current is constant, output voltage of alternator is increasing along
with the engine speed increasing.

System diagram

Stator coil
Engin-ECU

Excitation coil
Voltage
regulator Ignition switch
Battery
Charging alarm lamp

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Alternator specification

Item Specification
Type Battery voltage test type
Rating output power V/A 12/110
Voltage regulator Inside electronic regulation type

6.2 Repair specification

Item Standard value Limit value

Output line’s voltage drop of alternator (when 30A) V Max. 0.3
-20°C 14.2 ~ 15.4
Voltage regulation range 20°C 13.9 ~ 14.9
Using temperature of voltage
regulator 60°C 13.4 ~ 14.6
80°C 13.1 ~ 14.5
Output current 70% of output rating current

6.3 Special tool

Tool No. Name Use

MB991955 MUT-III and accessory Check when in idle speed.
A: MB991824 A: MUT-III detector NOTICE
B: MB991827 B: MUT-III USB interface Use MUT-III, main test line A
line can give off a simulation speed
C: MB991910
signal, main test line B can not.
C: MUT-III main connection
D: MB991911
lineA
E: MB991825
(use on the vehicle which
F: MB991826 installs communication con-
nection port)
D: MUT-III main connection
lineB
(use on the vehicle which
does not install communica-
tion connection port)
E: MUT-III test joint
F: MUT-III triggering line

Check the S end’s voltage of alter-

MB991519 Test line of alternator
nator.

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6.4 Output line’s voltage drop test of alternator

The objective of test is that find out whether the wiring (including fuse) of alternator B end and
battery (+) end is normal.

1. Before testing, check the following items.

1) Installation state of alternator.

2) Driving belt tension degree of alternator. (refer to the sequence of repair and regulation)

3) State of fuse.

4) Whether the alternator has abnormal noise in running.

2. Turn the ignition switch to “OFF” position.

3. Disassemble the cathode cable of battery.

4. Connect a caliper DC ammeter (range: 0-150A) to the output line of alternator B end.

NOTICE
Because of the inadequate connection between “B” end and output line, the method of
using the output line of disassembling alternator to connect ammeter can not find the
problem of output current decreasing.

5. Connect a digital voltmeter between alternator end “B” and battery jar (+) end. (Connect volt-
age (+) conductor to end “B”, connect voltage ( 一 ) conductor to battery jar (+) end.)

6. Connect cathode cable of battery jar again.

7. Connect MUT-III detector (display engine speed).

8. Keep the engine cover open.

9. Start the engine.

10. Under the state of the engine speed is 2500rpm/min, use the method of turning on or turn-
ing off the headlight and any other lamps to adjust the load of alternator, and make ammeter
finger point at the value more than 30A. Decrease the engine speed slowly and make the
indicator value of ammeter become 30A, and read the indicator value of voltmeter now. Limit
value: Max. 0.3V

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 BYD S6, S6A, S6K Service Manual

NOTICE
When the output power of alternator is big and can not make the indicator value of am-
meter decrease to 30A, adjust to 40A and read the indicator value of voltage difference.
The limit value is turning to max 0.4V now.

11. If the indicator value of voltmeter is higher than limit value; can consider that the output line
of alternator is not good, so check the wiring (including fuse) between alternator end “B” and
battery (+) end. If find the problem that the end is becoming flexible and the wiring is turning
color because of too hat, repair and test again.

12. After the test, make the engine running in idle speed.

13. Turn off all the lamps.

14. Turn the ignition switch to OFF position.

15. Disassemble MUT-III.

16. Disassemble the cathode cable of battery jar.

17. Disassemble the ammeter and voltmeter which are used to test.

18. Connect the cathode cable of battery jar.

6.5 Test of output current

Load
Voltmeter Ammter (caliper)

Combination instrument
Ignitiong seitch Charging alarm
lamp

Alternator
Engine ECU
Battery jar

The objective of this test is that find out whether the output current of alternator is normal.

1. Before testing, check the following items.

• Installation state of alternator.

• State of battery jar (refer to battery jar).

NOTICE
Battery jar needs to be discharged a little. Sometimes using full charged battery jar can
not do the test accurately because of lacking of electric load.

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• Tension degree of driving belt. (refer to the sequence of repair and regulation)

• State of fuse.

• Whether the alternator has abnormal noise in the engine running.

2. Turn the ignition switch to OFF position.

3. Disassemble cathode cable of battery.

4. Connect a caliper DC ammeter (range: 0-150A) to the output line of alternator B end.

NOTICE
Because of the inadequate connection between “B” end and output line, the method of
using the output line of disassembling alternator to connect ammeter can not find the
problem of output current decreasing.

5. Connect a 0-20 V testing voltmeter between end “B” and ground. (Connect voltage (+) con-
ductor to end “B”, connect voltage ( 一 ) conductor to ground.)

6. Connect cathode cable of battery jar.

7. Connect MUT-III detector. (Display engine speed).

8. Keep the opening state of engine cover.

9. Check the reading of voltmeter whether it is same to the voltage of battery jar.

NOTICE
If the voltage is 0V, consider that the connection between alternator end “B” and battery (+)
end disconnected or the fuse burned.

10. After turning on the lighting switch and headlight, start engine.

11. Turn the headlight to high beam position, turn the warmer switch to large air flow, and
then rise the speed to 2500 r/min, measure the max output current value on the ammeter.
Limit value: 70% of rating output current

NOTICE
• The rating output current value is explaining on the nameplate of alternator.
• Because the charge current may decrease rapidly after engine starting, you must
read the max current value quickly.
• The output current is changing along with the size of load or temperature of
alternator.
• When testing; if the electric load of vehicle is small, although the alternator is nor-
mal, it can not obtain the stated output current. Under this condition, you can adopt
to open the headlight to make the battery jar discharge or use the lamp on other ve-
hicle to increase the electric load, then do the test.
• When the temperature of alternator or surrounding environment is too high, some-
times can not reach the stated output current. Under this condition, do the test after
the engine is cooling.

12. The reading of ammeter should be more than limit value. If it is less than the limit value but
the output line of alternator is normal, disassemble the alternator from engine and check it.

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13. After testing, run the engine in the idle speed.

14. Turn the ignition switch to OFF position.

15. Disassemble MUT-III detector.

16. Disassemble cathode cable of battery jar.

17. Disassemble testing ammeter, voltmeter.

18. Connect the cathode cable of battery.

6.6 Test of voltage regulation

Load
Ammeter (caliper)

Combination instrument
Ignition seitch Charging
alarm lamp

Black

Alternator

Engine Blue
Battery jar ECU Red Yellow

Voltmeter (digital)

The objective of this test is that whether the voltage regulator can control the output voltage of al-
ternator or not.

1. Before doing the testing, check the following items.

• Installation state of alternator.

• State of battery jar (refer to battery jar).

• Tension degree of driving belt. (refer to the sequence of repair and regulation)

• State of fuse.

• Whether the alternator has abnormal noise in the engine running.

2. Turn the ignition switch to OFF position.

3. Disassemble cathode cable of battery.

4. Use special tool (alternator test line MB991519) to connect digital voltmeter to alternator “S”
end and ground (Connect voltage (+) conductor to end “B”, connect voltage ( 一 ) conductor
to ground or battery jar cathode).

5. Connect a caliper DC ammeter (range: 0-150A) to the output line of alternator B end.

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NOTICE
Because of the inadequate connection between “B” end and output line, the method of
using the output line of disassembling alternator to connect ammeter can not find the
problem of output current decreasing.

6. Connect the cathode cable of battery jar again.

7. Connect MUT-III detector (Display engine speed).

8. Turn on the ignition switch, check the reading of voltmeter whether it is same to the voltage
of battery jar.

NOTICE
If the voltage is 0V, consider that the connection between alternator end “B” and battery (+)
end disconnected or the fuse burned.

9. Turn off all the lights and accessories.

10. Start the engine.

11. Increase the engine speed to 2500 r/min.

12. Read the indicator value of voltmeter when decreasing the output current of alternator under
10A.

13. If the reading voltage value is same to the value in the voltage regulation table, it shows that
the function of voltage regulator is normal.

14. After testing, make the engine in idle speed.

15. Turn the ignition switch to OFF position.

16. Disassemble MUT-III detector.

17. Disassemble cathode cable of battery jar.

18. Disassemble testing ammeter, voltmeter.

19. Connect the output line of alternator to alternator “B” end.

20. Disassemble special tool, replace the joint.

21. Connect cathode cable of battery.

Standard value of voltage regulation

Using temperature of voltage

Check the end Standard value
regulator(°C)
-20 14.2 - 15.4
20 13.9 - 14.9
“S”
60 13.4 - 14.6
80 13.1 - 14.5

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Disassembly and assembly

Disassembly step
1. Oxygen sensor joint
2. Oxygen sensor joint
clip
<Vehicles for Hong Kong and Singapore>
3. A/C compressor as-
sembly joint
<Except for Hong Kong and Singapore>
4. A/C compressor joint
clip
5. Alternator joint
6. Alternator end
7. Joint bracket
8. Line clip
9. Alternator assembly.
• Timing belt lower cov-
er
10. Alternator assembly
bracket

Disassembly and assembly

Disassembly step
1. Front bracket assem-
bly
2. Engine wheel
3. Rotor
4. Rear bearing
5. Rear holder
6. Front bearing
7. Front bracket
8. Stator
9. Fixing plate
10. Regulator
11. Brush
12. Rubber gasket
13. Rectifier
14. Rear bracket

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1. Disassembly of front bracket assembly

NOTICE
Do not insert the screw driver too deep,
avoid damaging stator iron core.

Insert the flat head screw driver between front

cover and stator iron core, and divide them.

2. Disassembly of pulley

NOTICE
Do not injure rotor.

Make the side face of pulley upalong, fix the

rotor on the table vice, disassemble pulley.

3. Disassembly of stator/rectifier assembly

Rectifier Welding
assembly point NOTICE
• Use the 180 - 250 W electric iron to
disconnect the welding points in
4 seconds. Do not weld for a long
time, avoid transferring the heat of
electric iron to diode.
Welding • Do not pull the conductor of diode
point forcibly.

1) Disconnect the stator from rectifier as-

sembly.

2) When disassembling the rectifier from

the regulator, disconnect all the welding
points of rectifier.

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Operation essentials of assembly

1. Installation of regulator assembly

After installing the regulator assembly, push

the brush into one side.

Wire Insert the wire into the hole of rear cover to

fasten the brush.

NOTICE
Insert the wire to fasten the brush, it is
more easy to install the rotor.

Rear bracket

Brush

Line

2. Installation of rotor

After installing the rotor, disassemble the

brush line.
Wire

Inspection:

Rotor

1. Measure the resistance between two

vanes of stator coil, and check the guide
circuit between them.
Standard value: 3 - 5 Ω

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2. Check the guide circuit between vane

and iron core. If it is, replace the rotor.

Stator

1. Check the guide circuit between coil

heads. If it is, replace the stator.

2. Check the guide circuit between coil and

center. If it is, replace the stator.

Rectifier assembly

1. Check the guide circuit between connec-

tion end of every stator coil and radiator
plate (+). If it is, the diode is short circuit,
replace the rectifier assembly.

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2. Check the guide circuit between connec-

tion end of every stator coil and radiator
plate (-). If it is, diode is short circuit, re-
place rectifier assembly.

3. Connect two ends of every diode with

ammeter, check the six diodes whether
they are guide circuit.

If the two directions are not guide circuit,

the diode is damaged, must replace ra-
diator component.

Brush

1. Measure the exerted length of brush, if

the exerted length is shorter than stan-
dard value, replace the brush.
Exserted
length Standard value: ≥ 2 mm

2. Before disassembling, disconnect the

brush head.

3. When installing new brush, weld the

Welding point brush head under the state of pressing
the brush into brushes bracket as the
picture.

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7. Starting system
7.1 Summary

Turn the ignition switch to “start” position, the current inputs into the coil in the electromagnetic
switch to attract the iron core, the iron core is attracted, the bar connecting with the iron core is
doing to make the starter clutch connect. On the other hand, attracted iron core make the electro-
magnetic switch guide circuit, and make the B end and D end guide circuit, so the current make
the engine work. When the ignition switch turn to “ON” position again, starter clutch disconnect
from gear ring.

There is a over speed clutch between pinion and armature shaft, use to prevent the starter dam-
aged.

Starter specification

Item Specification
Type Planetary gear subtrahend driving
Rating output power kW/V 1.4/12
Gear number 8

Repair specification

Item Standard value Using limit

Pinion clearance mm 0.5 - 2.0 -
Redirector exerted quantity mm 0.05 0.1
Redirector diameter mm 29.4 28.8
Backoff depth mm 0.5 0.2

Disassembly and assembly

Operate before disassembling: Operate after assembling:

• Assemble the air intake pipe.
Disassemble the air intake pipe.
• Fill the transmission oil.

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Disassembly step
1. Oil pipe
2. O type ring
3. Radiator pipe clip
4. Service pipe
5. Return pipe
6. ATF warmer
7. Starter cover
8. Wiring harness clip
9. Starter joint
10. Starter end
11. Starter
12. Starter cover bracket

<<A>> Disassembly of ATF warmer (A/T

FLUID COOLER)

Disassemble the ATF warmer (A/T fluid cool-

er) with water pipe from the front positive stop
bracket of transmission. Move the component
to battery side, and support it well, do not
ATF warmer
(A/T fluid cooler)
intervene with disassembly and assembly of
starter assembly.

Battery jar

<<B>> Disassembly of starter cover

Disassemble the bolts of starter cover, disas-

ATF warmer semble the starter cover from the side of ATF.
(A/T fluid cooler)

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<<C>> Disassembly of wiring harness clip/

joint/starter end

Disassemble the installation bolts of starter,

loosen the wiring harness clip, starter joint
and starter end.

<<D>> Disassembly of clutch oil pump

<M/T>

Disassemble screw of clutch oil pump, lay the

Clutch main clutch oil pipe at the different place which can
cylinder not intervene with the starter disassembly.

<<E>> Disassembly of starter assembly

Disassemble the starter assembly from the

vehicle.

<<F>> Disassembly of starter assembly

Disassemble the starter assembly from the

place which is installing the ATF warmer (A/T
fluid cooler).

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7.2 Inspection of starter motor

Regulation of pinion clearance

1. Disconnect the magnetic coil from the M

end of magnetic switch.
Switch
2. Connect 12V battery between S end and
M end.

3. Turn on the ignition switch “ON”, discon-

Battery jar nect the pinion.
Starting
Line
motor NOTICE
AKX01238 AF
Test must be rapid (less than 10 sec-
onds), prevent burning the coil.

4. Check the clearance with clearance

gauge between gear and stopper.
Stopper Standard value: 0.5 - 2.0 mm

Small gear
Small gear clearance

5. If the clearance between pinions ex-

ceeds the standard value, adjust through
increase or decrease the gaskets be-
tween magnetic switch and front bracket.

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Inhalation test of magnetic switch

1. Disconnect the magnetic coil from the M

end of magnetic switch.
Switch
2. Connect 12V battery jar between S end
and M end.

NOTICE
Battery jar
Starting Test must be rapid (less than 10 sec-
Line
motor onds), prevent burning the coil.

3. If the pinion moves out, the inhalation

coil is well. If it does not, replace mag-
netic coil.

Holding test of magnetic coil

1. Disconnect the magnetic coil from the M

end of magnetic switch.
Switch
2. Connect 12V battery jar between S end
and M end.

NOTICE
Battery jar
Starting Test must be rapid (less than 10 sec-
motor Line
onds), prevent burning the coil.

3. Push the pinion to stopper position by

hand.

4. If the gear moves out, it is normal; if the

gear moves in, replace the magnetic
switch.

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Free running test

Ammeter 1. As the picture, connect the starting

motor to 12V battery jar which has full
charge.
Variabl resistor
2. Connect the ammeter and variable resis-
tor between battery jar anode end and
Battery jar starting motor end.
Starting
motor Voltmeter 3. Connect the voltmeter between starting
motor.

4. Rotate the variable resistor to full resis-

tance position.

5. Connect the cathode of battery jar to

starting motor body.

6. Adjust the variable resistor to 11V.

7. Confirm the max current whether it is in

the stated range and the starting motor
can free running.
Current: Max 90 Amps

Rotating test of magnetic switch

1. Disconnect the magnetic coil from the M

end of magnetic switch.
Switch
2. Connect 12V battery jar between body
and M end..

Battery jar NOTICE

Starting
Line Test must be rapid (less than 10 sec-
motor
onds), prevent burning the coil.

3. Push the gear out, and then loosen it,

If the gear return to the original position
quickly, it is normal; if it does not, replace
magnetic coil.

WARNING
Take care of your finger when pushing
the gear.

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Disassembly and assembly

Disassembly step

1. Screw 2. Electromagnetic switch 3. Screw

4. Bolt 5. Rear bracket 6. Brush bracket
7. Rear bearing 8. Armature 9. Magnetic component
10. Gasket A 11. Gasket B 12. Board
13. Planetary gear 14. Bar 15. Clip spring
16. Stop ring 17. Overspeed clutch 18. Inner gear
19. Planetary gear shaft 20. Front bracket

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 BYD S6, S6A, S6K Service Manual

<<A>> Disassembly of electromagnetic

valve

NOTICE
Mafnetic switch S end
Do not use the pliers to clip the magnetic
component.
B end
Disassemble the lead wire from M end of
M end electromagnetic switch.
Excatation
coil head

<<B>> Disassembly of clip spring and

stop ring

1. Use proper sleeve wrench, twist the

wrench towards the direction of pinion
Sleeve wrench side, and disassemble the stop ring.

Stop ring Amall gear

Overspeed
clutch

2. Use the clip spring clamp to disassemble

Clip spring the clip spring, and then disassemble the
Clip spring
stop ring and overspeed clutch.
clamp Small gear

Overspeed
clutch

Parts clean of starter motor

1. Parts can not clean in the cleaning 2. Driving parts can not clean in the clean-
agent, putting the component of magnet- ing agent, the overspeed clutch have
ic, excitation coil in the cleaning agent been oiled before leaving factory, when
can damage its insulating. cleaning in the cleaning agent, the clean-
ing agent may wash away the lubrication
oil in the clutch.

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>>A<< Assembly of stop ring and clip

spring

Use the proper tool, stride over clip spring

and pull the stop ring to the direction of clip
spring.

Overspeed Stop ring

Stop ring clutch

Clip spring

Rotor

1. Put the rotor on one pair of V type

blocks, check its radial run-out with dial
indicator.
Stand value: ≤ 0.05 mm

Using Limit: 0.1 mm

2. Measure the diameter of rotor

Standard value: 29.4 mm

Limit value: 28.8 mm

3. Check the immersing depth of mica be-

tween rectifier cells.
Depth Standard value: 0.5 mm
Rectifier
cell Mica
Limit value: 0.2 mm

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 BYD S6, S6A, S6K Service Manual

Brush bracket

Push the brush into brush bracket, confirm

whether the brush bracket is normal, or re-
place the brush bracket.

Overspeed clutch

1. Confirm whether the pinion is resisted

when left rotating, and running repose-
fully when right rotating.

2. Check the condition of abrasion and

damage.
Free

Lock

Brush

1. Check the roughness of interface be-

tween brush and rectifier, and check the
length of brush, replace when the length
of brush bracket is less than limit value.

Brush length Limit value: 7.0 mm

2. When Correcting the brush interface or

replace new brush, can wind the emery
paper around the brush and repair.

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 BYD S6, S6A, S6K Service Manual

Armature coil

1. Coil short circuit test of rotor.

Growler
2. Put the rotor on the tester of coil short
circuit.

NOTICE
Do the test after cleaning the rotor sur-
face drastically.

3. Put the tagger on the top of rotor and

keep parallel between tagger and ro-
tor center shaft, rotate the rotor slowly,
observe the tagger. If the tagger is not
attracted, and no shaking, the rotor is
normal.

4. Check the insulating condition between

rectifier cell of rectifier and rotor iron
core. If it can not guide circuit, it is nor-
mal.

5. Open circuit inspection of rotor coil,

check the guide circuit condition among
every rectifier cells. If it can guide circuit,
it is normal.

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Section 2 Engine electronic control system-2

1. Troubleshooting Procedures
Procedure 1: Communication with ECU Difficulty
Procedure 1: Communication with ECU Difficulty

Notice: There shall be data communication between 7# terminal at the output end of diag-
nostic connector and the A48-22# terminal of engine ECU.

Symptoms of Malfunction Possible Causes

It may be caused by malfunction detected by engine 1. ECU power circuit short or open circuit
ECU or open circuit or short circuit at the diagnostic 2. Circuit between ECU and diagnostic connector
connector. short circuit.
3. ECU malfunction

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 BYD S6, S6A, S6K Service Manual

Diagnostic procedures:

1. Check if the engine starts normally. If

abnormal, check the engine-ECU power
supply, control relay, ignition switch IG1.
If normal, go to next step.

2. Check the ECU connector. If abnormal,

repair or replace. If normal, go to next
step.

3. Check the CG26 (7# terminal of diag-

nostic connector) and the A48 (22#
terminal of ECU). If abnormal, repair. If
normal, go to next step.

4. Check the symptom of malfunction. If

abnormal, replace the ECU. If normal, it
is an intermittent malfunction.

NOTICE
Check the Ac05 connector before check-
ing the wire harness; if abnormal, repair
first.

Procedure 2:Engine Warning Light Isn’t Illuminated When Ignition Switch Turned to ON

Symptoms of Malfunction Possible Causes

When the ignition switch is turned to ON, the en- 1. Bulb malfunction
gine warning light comes on immediately and five 2. Engine warning light circuit malfunction (short
seconds later goes out automatically. or open circuit)
If the engine warning light doesn’t come on, there
may be malfunctions as shown in the right col-
umn.

Diagnostic procedures:

1. Read DTC with MUT-III. If any DTC, refer to the diagnostic procedures. If no DTC, go to next
step.

2. Check the symptom of malfunction. If it still exists, replace the instrument panel assembly. If
not, it is an intermittent malfunction.
Procedure 3: Engine Warning Light Doesn’t Go Out

Symptoms of Malfunction Possible Causes

It may indicate that the engine ECU detected Wire harness short circuit of instrument panel
malfunctions on certain sensor or actuator, or as
shown in the right column.

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 BYD S6, S6A, S6K Service Manual

Diagnostic procedures:

1. Read DTC with MUT-III. If any DTC, refer to the diagnostic procedures. If no DTC, go to next
step.

2. Check the symptom of malfunction. If it still exists, replace the instrument panel assembly. If
not, it is an intermittent malfunction.
Procedure 3: Engine Cannot Start (Starter Running with No Ignition )

Symptoms of Malfunction Possible Causes

Poor ignition circuit, poor fuel supply or other reasons • Poor battery
• Open circuit timing belt
• Dirty throttle body
• Ignition system malfunction
• Fuel supply system malfunction
• Limit switch malfunction
• Engine ECU malfunction

Diagnostic procedures:

1. Check the battery voltage: measure at

engine starting. Standard value: ≥ 8V. If
abnormal, check the battery (refer to the
Battery Test Procedures). If normal, go
to next step.

2. Communication with MUT-III. Check if

the communication between the MUT-III
and the engine ECU is normal. If nor-
mal, go to next step; if abnormal, check
the engine ECU power supply, the con-
trol relay and the ignition switch IG1 sys-
tem. (Refer to Procedure 22).

3. MUT-III diagnostic DTC. If any DTC,

refer to the diagnostic procedures. If no
DTC, go to next step.

4. MUT-III actuator function test.

Standard value: fuel pump running
noise can be heard.

If abnormal, check the fuel pump system

(refer to Procedure 23). If normal, go to
next step.

5. Check the damage of timing belt.

Engine: running
Standard value: camshaft rotating

If abnormal, replace the timing belt. If

normal, go to next step.

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6. Check the throttle body (a part of throttle

valve) for dirt.

If abnormal, clean the throttle body. If

normal, go to next step.

7. Check data stream with MUT-III.

If abnormal, go to Step 8 (manual) or

Step 9 (automatic). If normal, go to Step
10.

8. Engine ECU connector.

If abnormal, repair or replace. If normal,

check the intermediate connector.

The same as Step 8.

9. Check data stream with MUT-III. Re-

fer to the data stream table A Item 22:
Crankshaft Angle Sensor. If abnormal,
check the crankshaft angle sensor. If
normal, go to next step.

10. Check the sound when the fuel injector

is working. If abnormal, check the fuel
injector of the faulty cylinder. If normal,
go to next step.

11. Check the ignition coil. If abnormal,

check the ignition circuit system. If nor-
mal, go to next step.

12. Conduct a fuel pressure test. If abnor-

mal, repair. If normal, go to next step.

13. Replace the engine ECU.

After the ECU is replaced, check the

symptom of malfunction again. If it dis-
appears, stop checking. If it still exists,
check if there is water or other impurities
in fuel.

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Procedure 4: Engine Cannot Start (Car Does Not Start Even with Ignition On) Engine Can-
not Start (Long-Time Start)

Symptoms of Malfunction Possible Causes

It may be caused by weak spark from the spark plug • Battery malfunction
or improper air-fuel ratio in engine starting or too low • Ignition system malfunction
compression pressure .. • Fuel system malfunction
• Air-fuel ratio control system malfunction
• Intake system malfunction
• Exhaust gas recycling system malfunction
• Dirty throttle body
• Misplaced timing belt
• Fuel injector malfunction
• Too low compression pressure
• ECU malfunction

Diagnostic procedures:

1. Check the battery status. If normal, let the engine idle for 10 minutes after it gets hot. If ab-
normal, go to next step.

2. Check the battery voltage. Standard value: ≥ 8V. If abnormal, check the battery. If normal,
go to next step.

3. MUT-III DTC. If any DTC, refer to the troubleshooting procedures. If no DTC, go to next step.

4. Check data stream with MUT-III. Refer to the data stream table. If abnormal, check abnormal
sensor. If normal, go to next step.

5. Check data stream with MUT-III. Item 25: Atmospheric Pressure Sensor. If abnormal, replace
it. If normal, go to next step.

6. Check if the throttle body is dirty. If abnormal, clean the throttle body. If normal, go to next
step.

Test the actuator with MUT-III. Item 07: Fuel Pump. Standard: the sound of fuel pump
working can be heard. If abnormal, check the fuel pump system. If normal, go to next step.

7. Check the intake pipe and the intake manifold for intake condition. If abnormal, repair it. If
normal, go to the next step.

8. Check the fuel nozzle for working sound. If abnormal, check the fuel injector of the faulty cyl-
inder. If normal, go to next step.

9. Check the timing belt for timing mark. If abnormal, adjust the timing mark. If normal, go to
next step.

10. Check the ignition coil. Check the ignition coil. If abnormal, check the ignition circuit (Refer to
Procedure 26). If normal, go to next step.

11. Check the injection nozzle for the atomizing condition. If abnormal, repair the nozzle. If nor-
mal, go to next step.

12. Check the fuel pressure. If abnormal, repair it. If normal, go to next step.

13. Check the EGR solenoid valve (stepper motor). If abnormal, replace it. If normal, go to next
step.

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14. Replace the engine ECU. After it is replaced, check the symptom of malfunction again. If it dis-
appears, stop checking. If it still exists, check if there is water or other impurities in the fuel.
Procedure 5: Unstable Idling, Too High&Low Idle Speed, Engine Stall in Idle

Symptoms of Malfunction Possible Causes

It may be caused by poor ignition system, improper • Ignition system malfunction
air-fuel ratio or poor ISC stepper motor or too low • Fuel system malfunction
compression pressure. Many reasons may cause • Throttle valve control system malfunction
the failure, start troubleshooting from the simple • Air-fuel ratio control system malfunction
items.
• Intake and exhaust system malfunction
• Dirty throttle body
• Misplaced timing belt
• Improper pressure
• Engine ECU malfunction
• EGR emission control system malfunction

Diagnostic procedures:
1. Check the battery status. If the battery
terminals are disassembled, leave the
engine idling for 10 minutes after pre-
heated.
If not disassembled, go to next step.
2. Check if any DTC exists by the “Self-Di-
agnosis” function on the MUT-III. If any
DTC, refer to the diagnostic procedures.
If no DTC, go to next step.
3. Check the data stream with MUT-III.
Refer to the data stream table.If
abnormal,check abnormal sensor. If nor-
mal, go to next step.
4. Check data stream with MUT-III. Item
25: Atmospheric Pressure Sensor. If ab-
normal, replace the ECU. If normal, go
to next step.
5. Check the intake pipe and the intake
manifold for intake condition. If abnor-
mal, repair it. If normal, go to next step.
6. Check the timing belt for timing mark. If
abnormal, adjust the timing mark. If nor-
mal, go to next step.
7. Check if the throttle body is dirty. If ab-
normal, clean the throttle body. If nor-
mal, go to next step.
8. Check data stream with MUT-III.
If abnormal, check the abnormal sensor
.If normal, go to next step.

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9. Check the voltage of engine ECU con-

nector.

• Measure the terminal voltage of

ECU.

• Engine: Running idle after warm up

• Transmission: N or P gear

• Radiator fan: not running

• Voltages at 45# terminal and

grounding terminal
Standard: Headlight switch is turned
off and then on, the voltage will in-
crease.

If normal, go to Step 13. If abnormal, go

to next step.

10. Check the engine ECU connector and the

generator connector. If abnormal, repair
or replace. If normal, go to next step.

11. Check the wire harness between the en-

gine ECU connector and the generator
connector.

NOTICE
Check the intermediate connector B-17
before checking the wire harness.

If abnormal, repair it. If normal, replace

the generator and then go to next step.

12. Check the symptom of malfunction. If it

disappears, the check is completed. If it
still exists, replace the engine ECU.

13. Check the spark plug. If abnormal, re-

place it. If normal, go to next step.

14. Check the ignition coil. If abnormal,

check the ignition circuit system. (Refer
to Procedure 26). If normal, go to next
step.

15. Check canister control solenoid valve.

If abnormal, replace it. If normal, go to
next step.

16. Check the EGR solenoid valve (stepper

motor). If abnormal, replace it. If normal,
go to next step.

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17. Check the injection nozzle for the atom-

izing condition. Check each fuel injector
for atomizing condition. If abnormal, re-
place it. If normal, go to next step.

18. Check the fuel pressure. If abnormal, re-

pair it. If normal, go to next step.

19. Replace the engine ECU. After it is re-

placed, check the symptom of malfunc-
tion again. If it disappears, stop check-
ing. If it still exists, check if there is water
or other impurities in the fuel.

Procedure 6: Engine Stalling When Started

Symptoms of Malfunction Possible Causes

It may be caused by too weak spark or improper • Ignition system malfunction
air-fuel ratio when the accelerator pedal is pressed • Intake system malfunction
down.
• Oil gas evaporative system malfunction
• Engine ECU malfunction

Diagnostic procedures:

1. Read DTC with MUT-III. If any DTC, refer to the diagnostic procedures. If no DTC, go to next
step.

2. Check data stream with MUT-III. Refer to data stream test table:

If abnormal, check the abnormal sensor. If normal, go to next step.

3. Check the EGR solenoid valve (stepper motor). If abnormal, replace it. If normal, go to next
step.

4. Check the intake pipe and the intake manifold for intake condition. If abnormal, repair it. If
normal, go to next step.

5. Check the spark plug. If abnormal, replace it. If normal, go to next step.

6. Check the ignition coil. If abnormal, check the ignition circuit system. If normal, replace the
ECU.
Procedure 7: Engine Stalling in Acceleration

Symptoms of Malfunction Possible Causes

It may be caused by insufficient intake, poor exhaust • Throttle valve control system malfunction
gas recycling system, or improper air-fuel ratio, etc. • Ignition system malfunction
• Oil gas evaporative system malfunction
• Dirty throttle body
• Engine ECU malfunction

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Diagnostic procedures:

1. Read DTC with MUT-III. If any DTC, refer to the diagnostic procedures. If no DTC, go to next
step.

2. Check data stream with MUT-III. Refer to data stream test table.

If abnormal, check the abnormal sensor. If normal, go to next step.

3. Check the EGR solenoid valve (stepper motor). If abnormal, replace it. If normal, go to next
step.

4. Check if the throttle body is dirty. If abnormal, clean the throttle body. If normal, go to next
step.

5. Check the spark plug. If abnormal, replace it. If normal, go to next step.

6. Check the ignition coil. If abnormal, check the ignition circuit system. If normal, replace the
ECU.
Procedure 7: Engine Fails to Accelerate

Symptoms of Malfunction Possible Causes

It may be caused by poor fuel system, throttle valve • Ignition system malfunction
control system, ignition system, etc. • Fuel system malfunction
• Throttle valve control system malfunction
• Engine ECU malfunction

Diagnostic procedures:

1. Read DTC with MUT-III. If any DTC, refer to DTC procedures. If no DTC, go to next step.

2. Test data stream with MUT-III. Refer to data stream test table:

If abnormal, check the abnormal sensor. If normal, go to next step.

3. Check the ignition coil. If abnormal, check the ignition circuit system. (Refer to Procedure
26). If normal, go to next step.

4. Check the timing belt for timing mark. If abnormal, adjust the timing mark. If normal, go to
next step.

5. Check the spark plug. If abnormal, replace it. If normal, go to next step.

6. Measure fuel pressure. If abnormal, repair it. If normal, replace the ECU.

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Procedure 8: Delayed Engine, Decreased Rotation, Sluggish Acceleration

Symptoms of Malfunction Possible Causes

It may be caused by poor ignition system, improper • Air-fuel ratio control system malfunction
air-fuel ratio, poor throttle valve control system or • Ignition system malfunction
pressure.
• Fuel supply system malfunction
• Intake and exhaust system malfunction
• Oil gas evaporative system malfunction
• Throttle valve control system malfunction
• Poor compression pressure
• Engine ECU malfunction

Diagnostic procedures:

1. Read DTC with MUT-III. If any DTC, follow troubleshooting procedures. If no DTC, go to next
step.

2. Check the noises when the fuel injector is working. If abnormal, check the fuel injector of the
faulty cylinder. If normal, go to next step.

3. Check data stream with MUT-III. Refer to data stream test table:

If abnormal, check the abnormal sensor. If normal, go to next step.

4. Check data stream with MUT-III. Item 25: Atmospheric Pressure Sensor. If abnormal, replace
the ECU. If normal, go to next step.

5. Check canister control solenoid valve If abnormal, replace it. If normal, go to next step.

6. Check the EGR solenoid valve (stepper motor). If abnormal, replace it. If normal, go to next
step.

7. Check data stream with MUT-III.

If abnormal, check the abnormal sensor. If normal, go to next step.

8. Check the spark plug. If abnormal, replace it. If normal, go to next step.

9. Check the ignition coil. If abnormal, check the ignition circuit system. (Refer to Procedure
26). If normal, go to next step.

10. Check if the throttle body is dirty. If abnormal, clean the throttle body. If normal, go to next
step.

11. Measure fuel pressure If abnormal, repair it. If normal, go to next step.

12. Check the compressor pressure. If abnormal, repair it. If normal, replace the ECU.
Procedure 9: Impact or Vibration Is Felt in Acceleration

Symptoms of Malfunction Possible Causes

It may be caused by the electric leakage resulted from • Ignition system malfunction
the increase of voltage as required by the spark plug in • Throttle valve control system malfunction
acceleration. Or, it may be caused by poor throttle valve
• Dirty throttle body
control system.
• Engine ECU malfunction

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Diagnostic procedures:

1. Read DTC with MUT-III. If any DTC, refer to the diagnostic procedures. If no DTC, go to next
step.

2. Check the data stream with MUT-III. Refer to the data stream table.

If abnormal, check the abnormal sensor. If normal, go to next step.

3. Check if the throttle body is dirty. If abnormal, clean the throttle body. If normal, go to next
step.

4. Check the spark plug. If abnormal, replace it. If normal, go to next step.

5. Check the ignition coil. If abnormal, check the ignition circuit system. (Refer to Procedure
26). If normal, replace the ECU.
Procedure 10: Impact or Vibration Is Felt in Deceleration

Symptoms of Malfunction Possible Causes

The insufficient intake may be caused by throttle • Throttle valve control system malfunction
valve control system malfunction. • Dirty throttle body
• Engine ECU malfunction

Diagnostic procedures:

1. Read DTC with MUT-III. If any DTC, refer to DTC procedures. If no DTC, go to next step.

2. Check the data stream with MUT-III. Refer to the data stream table.

If abnormal, check the abnormal sensor. If normal, go to next step.

3. Check if the throttle body is dirty. If abnormal, clean the throttle body. If normal, replace the
ECU.

4. Check the spark plug. If abnormal, replace it. If normal, go to next step.

5. Check the ignition coil. If abnormal, check the ignition circuit system. (Refer to Procedure
26). If normal, replace the ECU.
Procedure 11: Knock

Symptoms of Malfunction Possible Causes

It may be caused by poor knock control or improper • Knock sensor malfunction
setting of heat value of spark plug. • Knock control system malfunction
• Ignition system malfunction
• Improper heat value grade of spark plug
• Engine ECU malfunction

Diagnostic procedures:

1. Read DTC with MUT-III. If any DTC, refer to DTC procedures. If no DTC, go to next step.

2. Check the spark plug. If abnormal, replace it. If normal, go to next step.

3. Check the ignition coil. If abnormal, check the ignition circuit system. (Refer to Procedure
26). If normal, check the knock sensor.

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Procedure 12: Ignition Timing Shift

Symptoms of Malfunction Possible Causes

It may be caused by improper position of crankshaft • Crankshaft angle sensor
angle sensor, camshaft position sensor or timing • Camshaft position sensor malfunction
belt.
• Improper timing belt position
• Engine ECU malfunction

Diagnostic procedures:

1. Read DTC with MUT-III. If any DTC, refer to DTC procedures. If no DTC, go to next step.

2. Measure the output waveform of crankshaft angle sensor or camshaft position sensor (with
an oscilloscope).

Crankshaft angle sensor

Connect the intermediate connector Ab22-2

of crankshaft angle sensor with a special test
cable (MB991658) and measure the voltage.

• Engine: idle

• Transmission: N or P gear

• Measure the voltage between 2# termi-

nal and grounding terminal

Camshaft position sensor

Connect the camshaft position sensor con-

nector Ab05-2 with a special test cable
(MB991709) and measure the voltage.

• Engine: idling

• Transmission: N or P gear

• Measure the voltage between 2# termi-

nal and grounding terminal

Standard: The two sensors shall output

waveform synchronously.

If normal, go to Step 3. If abnormal, go to

Step 4.

3. Check the symptom of malfunction. If it still exists, replace the engine ECU. It means inter-
mittent fault if the fault disappears.
4. Check if the crankshaft angle sensor and the camshaft position sensor are properly installed.
If abnormal, repair. If normal, go to next step.
5. Check the timing belt for timing mark. If abnormal, adjust the timing mark. If normal, go to
next step.
6. Check the signal wheel of crankshaft. If abnormal, change it. If normal, go to next step.
7. Check the signal wheel of camshaft and if abnormal, change it. If normal, go to next step.

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8. Replace the crankshaft angle sensor. After replacing, check the symptom of malfunction
again. If it disappears, the check is completed. If it still exists, go to next step.

9. Replace the camshaft position sensor. After replacing, check the symptom of malfunction
again. If it disappears, it is an intermittent malfunction. If it still exists, replace the engine
ECU.
Procedure 13: After-Burning

Symptoms of Malfunction Possible Causes

There may be fuel leakage in fuel injector. • Fuel injector malfunction
• Engine ECU malfunction

Diagnostic procedures:

Check the injection nozzle for the atomizing condition. Check each fuel injector for atomizing con-
dition. If abnormal, replace the nozzle. If normal, replace the ECU.
Procedure 14: Pungent Exhaust Smell, White or Black Smoke, Too High CO or HC Concen-
tration in Idling

Symptoms of Malfunction Possible Causes

It may be caused by abnormal air-fuel ratio, poor • Air-fuel ratio control system malfunction
catalytic converter, or ignition system malfunction, • Ignition system malfunction
etc.
• Fuel system malfunction
• Intake and exhaust system malfunction
• Oil gas evaporative system malfunction
• Improper compression pressure
• Catalytic converter malfunction
• Engine ECU malfunction

Diagnostic procedures:

1. MUT-III DTC. If any DTC, refer to DTC troubleshooting procedures. If no DTC, go to next
step.

2. Check the fuel nozzle for working sound. If abnormal, check the fuel injector of the faulty cyl-
inder. If normal, go to next step.

3. Check ignition timing. If abnormal, check the ignition timing shifting (refer to Procedure 16). If
normal, go to next step.

4. Check data stream with MUT-III. Refer to the data stream table.

If abnormal, check the abnormal sensor. If normal, go to next step.

5. Check data stream with MUT-III. Item 25: atmospheric pressure sensor. If abnormal, replace
the ECU. If normal, go to next step.

6. Check the intake pipe and the intake manifold for intake condition. If abnormal, repair it. If
normal, go to next step.

7. Check the exhaust manifold for fuel leakage. If abnormal, repair it. If normal, go to next step.

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8. Check if the throttle body is dirty. If abnormal, clean the throttle body. If normal, go to next
step.

9. Check data stream with MUT-III.

If abnormal, check the abnormal sensor. If normal, go to next step.

10. Check canister control solenoid valve. If abnormal, replace it. If normal, go to next step.

11. Check the EGR solenoid valve (stepper motor). If abnormal, replace it. If normal, go to next
step.

12. Check the fuel pressure. If abnormal, repair it. If normal, go to next step.

13. Check the PCV valve. If abnormal, replace it. If normal, go to next step.

14. Check the spark plug. If abnormal, replace it. If normal, go to next step.

15. Check the ignition coil. If abnormal, check the ignition circuit system. (Refer to Procedure
26). If normal, go to next step.

16. Check the compressor pressure. If abnormal, repair it. If normal, go to next step.

17. Check the injection nozzle for atomizing condition. If abnormal, replace the nozzle. If normal,
go to next step.

18. Replace the catalytic converter. After replacing, check the symptom of malfunction again. It if
disappears, the check is completed. If it still exists, replace the engine ECU.
Procedure 15: Battery Leakage

Symptoms of Malfunction Possible Causes

It may be caused by poor generator, or poor control • Battery malfunction
circuit, etc. • Short circuit of generator G terminal
• Alternator malfunction
• Engine ECU malfunction

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Diagnostic procedures:

1. Check the battery voltage. Standard

values : ≥ 8V

If abnormal, check the battery. If normal,

go to next step.

2. Check the alternator connector Ab25-3.

If abnormal, repair it. If normal, go to

next step.

3. Measure the output voltage of generator

connector Ab25-3.

• Remove the connector and mea-

sure at the wire harness side.

• Measure the voltages of 3# ter-

minal and grounding terminal
Standard value: System voltage

If normal, go to Step 5. If abnormal, go

to next step.

• Check if the power supply line is

short circuit or open circuit.

If abnormal, repair or replace.

4. Connector check: the engine ECU con-

nector. If abnormal, repair or replace. If
normal, go to next step.

5. Check the control voltage of engine

ECU connector.

• Remove the connector and mea-

sure at the wire harness side.

• Measure the voltages of A47-20#

terminal and grounding terminal
Standard value: System voltage

If normal, go to Step 8. If abnormal, go

to next step.

6. Check the wire harness between the

ECU connector A47-20 and the genera-
tor connector Ab25 (4# terminal).

• Check if the output line is short

circuit or open circuit.

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If normal, replace the generator. If ab-

normal, repair.

7. Check the control voltage engine ECU

connector A47.

• Measure the terminal voltage of

ECU.

• Engine: Idling after heated

• Transmission: N or P gear

• Radiator fan: not running

• Voltages of 20# terminal and

grounding terminal
Standard: when the headlight switch
is turned off and then on, the voltage
increases.

If abnormal, replace the generator. If

normal, go to next step.

8. Check the symptom of malfunction. If

the malfunction disappears, it is an in-
termittent malfunction. If it still exists,
replace the engine ECU.

Procedure 16: Overheating

Symptoms of Malfunction Possible Causes

It may be caused by poor engine cooling system, fan • Insufficient or improper engine water coolant
controller or water temperature sensor, etc. • Fan controller malfunction
• Water temperature sensor malfunction
• Thermostat malfunction
• Water pump malfunction
• Radiator malfunction
• Engine ECU malfunction

Diagnostic procedures:

1. MUT-III DTC. If any DTC, refer to DTC troubleshooting procedures. If no DTC, go to next
step.

2. Check the engine water coolant. If abnormal, replace or add water coolant. If normal, go to
next step.

NOTICE
If the coolant level is too low, check for leaking point and repair.

3. Test the actuator with MUT-III.

Item 21: Fan controller.

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Standard: The fan motor rotating

If abnormal, check the fan control relay system (refer to Procedure 24). If normal, go to next
step.

4. Check data stream with MUT-III. Refer to the data stream table.

Item 21: Engine water temperature sensor

Standard values: cold machine status: ambient temperature (atmospheric temper-
ature)

Hot machine status: 80 - 110° C

If abnormal, check the water temperature sensor system.If normal, go to next step.

5. Check the thermostat. If abnormal, replace it. If normal, go to next step.

6. Check the water pump If abnormal, replace it. If normal, replace the radiator.
Procedure 17: Fan Abnormal Rotation

Fan control circuit

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Description:

The 17# terminal or 9# terminal of engine ECU outputs a control signal to the fan controller.

Symptoms of Malfunction Possible Causes

Engine-ECU outputs a load signal to the fan control- • Fan controller malfunction
ler based on the engine coolant temperature, vehicle • Open circuit or short circuit of fan controller and
speed and A/C switch position, then the fan control- connector
ler controls the radiator fan, and the A/C condenser
• Engine - ECU malfunction
fan based on the load signal (The closer to 5V the
average voltage at the terminal is, the higher the fan
speed).

Diagnostic procedures:

1. Check the engine ECU connector A46.

If abnormal, repair or replace. If normal,
go to next step.

2. Check the engine ECU connector A46.

• Remove the connector and mea-

sure the resistance at the wire
harness side.

• Short circuit between 17# termi-

nal and grounding terminal
Standard: The fan motor stops run-
ning.

If it doesn’t stop, go to Step 4. If it stops,

go to next step.

3. Check the symptom of malfunction. If

the malfunction disappears, it is an in-
termittent malfunction. If it still exists,
replace the engine ECU.

Measure the control voltage of the en-

gine ECU connector A46 .
• Remove the connector and measure
the resistance at the wire harness
side.

• Measure the voltages of 17# terminal

and grounding terminal

Standard values: 4.9 - 5.1 V

If normal, replace the fan control motor.

If abnormal, go to next step.

4. Check the fan controller connector C22.

If abnormal, repair or replace it. If nor-
mal, go to next step.

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5. Check the wire harness between the en-

gine ECU connector A46 (17# terminal)
and the fan controller connector C22 (2#
terminal).

NOTICE
Check the connector A-16 before check-
ing the wire harness. If it is defect, repair
it first.

• Check if the output line is open.

If normal, replace the fan controller. If

abnormal, repair it.

Procedure 18: Fuel Pump System

Battery Main relay

Oil bump
Fuel pump
relay
Fuel pump motor

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Description:

• The battery voltage is transmitted from the battery to the 86# terminal of fuel pump relay (1)
and then from the 85# terminal of fuel pump relay (1) to the ECM.

• The battery voltage is transmitted from the 88# terminal of fuel pump relay (1) to the
88a#terminal of fuel pump relay (1) and the 4# terminal of fuel pump relay (2).

Symptoms of Malfunction Possible Causes

Engine ECU will play a role in controlling relay ON to • Fuel pump relay malfunction
supply power to fuel pump when engine is starting • Fuel pump malfunction
or operating.
• Fuel pump driving circuit wire harness connector is
poor contact, open circuit or short circuit.
• Engine ECU malfunction

Diagnostic procedures:

1. Check the relay joint of oil pump. If ab-

normal, repair or replace it. If normal, go
to next step.

2. Check the fuel pump relay. If abnormal,

replace it. If normal, go to next step.

3. Check if fuse F2/24 is normal; if abnor-

mal, replace it; if normal, go to next step.

4. Measure the executive voltage of fuel

pump control relay socket.

• Dismantle relay

• Power supply at “ON” position

• Check the voltages between

88,86# terminal and grounding.
Standard value: System voltage

If abnormal, replace the MCU. If normal,

go to next step.

5. Check the engine ECU connector A46:

• Remove the connector and mea-

sure at the wire harness side.

• Start the engine

• Voltage between 10# terminal

and grounding terminal
Standard values:Less than 1V

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If abnormal, check the intermediate

connector. If any malfunction, repair it
first and then check and repair the wire
harness between the connectors of fuel
pump relay.

• Check if the grounding is open

circuit or short circuit.

If normal, go to next step.

6. Check the fuel pump connector K15. If

abnormal, repair or replace it. If normal,
go to next step.

7. Measure the executive voltage of fuel

pump connector K15.

• Remove the connector and mea-

sure the resistance at the wire
harness side.

• Start

• Measure the voltage between 4#

terminal and grounding.
Standard value: System voltage

If normal, go to Step 9. If abnormal, go

to next step.

8. Check the wire harness between the

connector 88a of fuel pump control relay
and the connector K15 (4# terminal) of
fuel pump

NOTICE
Check the intermediate connector before
checking the wire harness.

• Check if the power supply line is

open circuit, short circuit or dam-
aged.

If abnormal, repair it. If normal, replace

the ECU.

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Procedure 19: Fan Control Relay System

Refer to A/C system

Procedure 20: A/C Compressor Relay System

Refer to A/C system

Procedure 21: Ignition Circuit System

Electricity

Ignition
coil
Ignition coil

Ignition coil

Ignition coil
Ignition coil

1# Cylinder 2# Cylinder 3# Cylinder 3# Cylinder

spark plug spark plug spark plug spark plug

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Symptoms of Malfunction Possible Causes

The engine-ECU switches on & off the primary cur- • Ignition coil malfunction
rent of ignition coil by turning on & off the power • Spark plug malfunction
transistor in the ignition coil.
• Connector contact malfunction or open or short cir-
cuit of cable
• Engine-ECU malfunction

Diagnostic procedures:

1. Check the spark plug. If abnormal, re-

place it. If normal, go to next step.

2. Check the ignition coil connector A08,

A19, A34 and A35.

If abnormal, repair or replace it. If nor-

mal, go to next step.

3. Check the ignition coil. If abnormal, re-

place it. If normal, go to next step.

4. Measure the executive voltage of igni-

tion coil joint A08, A19, A34 and A35.

• Remove the connector and mea-

sure at the wire harness side.

• Power supply “ON” position

• The voltage between 3# terminal

and grounding.
Standard value: System voltage

If normal, go to Step 6. If abnormal, go

to next step.

5. Measure the executive voltage of igni-

tion coil joint A08, A19, A34 and A35.

• Remove the connector and mea-

sure the resistance at the wire
harness side.

• Engine: running

• The voltage between 2# terminal

and grounding.
Standard values: 0.1 - 0.2 V

If normal, go to Step 10. If abnormal, go

to next step.

6. Check the engine ECU connector A47.

If abnormal, repair or replace. If normal,
go to next step.

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7. Measure the executive voltage of engine

ECU connector A47.

• Measure the terminal voltage of

ECU.

• Dismantle ignition coil joint A08,

A19, A34 and A35.

• Engine: running

1) The voltage between 4# termi-

nal and grounding (1# ignition
coil)

2) The voltage between 3# termi-

nal and grounding (2# ignition
coil)

3) The voltage between 13# ter-

minal and grounding (3# igni-
tion coil)

4) The voltage between 28# ter-

minal and grounding (4# igni-
tion coil)

Standard values: 0.1 - 0.2 V

If normal, check the wire harness be-

tween the engine ECU connector and
the ignition coil connector.

1) Check and repair the wire harness

between the 1# ignition coil con-
nector A19 (1# terminal) and the
ECU connector A47 (4# terminal).

2) Check and repair the wire harness

between the 2# ignition coil con-
nector A08 (1# terminal) and the
ECU connector A47 (3# terminal).

3) Check and repair the wire harness

between the 3# ignition coil con-
nector Ab34 (1# terminal) and the
ECU connector A47 (13# terminal).

4) Check and repair the wire harness

between the 4# ignition coil con-
nector A35 (1# terminal) and the
ECU connector A47(28# terminal).

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• Check open line of output line.

If abnormal, go to next step.

8. Check the wire harness between the

ignition coil connector and the engine
ECU connector.

1) Check and repair the wire harness

between the 1# ignition coil con-
nector A19 (1# terminal) and the
ECU connector A47 (4# terminal).

2) Check and repair the wire harness

between the 1# ignition coil con-
nector A08(1# terminal) and the
ECU connector A47 (3# terminal).

3) Check and repair the wire harness

between the 1# ignition coil con-
nector A34(1# terminal) and the
ECU connector A47 (13# terminal).

4) Check and repair the wire harness

between the 1# ignition coil con-
nector A35 (1# terminal) and the
ECU connector A47 (28# terminal).

• Check if the output line is short.

If abnormal, repair it. If normal, go to

next step.

9. Check the symptom of malfunction. If it

still exists,, replace the engine ECU. If it
disappears, it is intermittent malfunction.

Measure ignition coil joint A08, A19, A34

and A35.

• Remove the connector and mea-

sure the resistance between 2#
terminal at the wire harness side
and grounding.
Standard values: ≤ 2Ω

If normal, go to next step.

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If abnormal, check and repair the wire

harness between the ignition coil con-
nector and the car body grounding.

5) Check and repair the wire harness

between the 1# ignition coil con-
nector A19 (2# terminal) and the
car body grounding.

6) Check and repair the wire harness

between the 2# ignition coil con-
nector A08 (2# terminal) and the
car body grounding.

7) Check and repair the wire harness

between the 3# ignition coil con-
nector A34 (2# terminal) and the
car body grounding.

8) Check and repair the wire harness

between the 4# ignition coil con-
nector A35 (2# terminal) and the
car body grounding.

• Check if the grounding wire is

open circuit or damaged.

10. Check the wire harness between the

ignition coil connector and the engine
ECU connector.

1) Check and repair the wire harness

between the 1# ignition coil con-
nector A19 (1# terminal) and the
engine ECU connector A47 (4#
terminal).

2) Check and repair the wire harness

between the 2# ignition coil con-
nector A34 (1# terminal) and the
engine ECU connector A47 (3#
terminal).

3) Check and repair the wire harness

between the 3# ignition coil con-
nector A34 (1# terminal) and the
engine ECU connector A47 (13#
terminal).

4) Check and repair the wire harness

between the 4# ignition coil con-
nector A35 (1# terminal) and the
engine ECU connector A47(28#
terminal).

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• Check if the output line is dam-

aged.

If abnormal, repair it. If normal, go to

next step.

Procedure 22: Oxygen Sensor Heater System of Upstream Cylinder

Description:

• The power supply is transmitted from the engine control relay (85# terminal) to the power ter-
minal (2# terminal) of oxygen sensor heater for upstream cylinder.

• The power transistor of engine ECU (8# terminal) controls the oxygen sensor heater (4# ter-
minal) for cylinder 1.

Symptoms of Malfunction Possible Causes

The power supply of oxygen sensor heater for up- • Upstream oxygen sensor heater malfunction
stream is controlled by turning on/off the power tran- • Connector contact malfunction or open circuit or
sistor of engine ECU. short circuit of cable
• Engine-ECU malfunction

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Battery

Main
relay
15A

Main
relay

Front oxygen sensor

Shield layer
Shield layer

Diagnostic procedures:

1. Check the upstream cylinder oxygen

sensor connector A20. If abnormal, re-
place it. If normal, go to next step.

2. Measure the executive resistance of up-

stream oxygen sensor connector A20.

• Remove the connector and mea-

sure at the sensor side.

• The resistance between 2# and

4# terminal
Standard value:11 - 18 Ω

If abnormal, replace it. If normal, go to

next step.

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3. Measure the executive voltage of the

joint of oxygen sensor A20 in upstream.

• Remove the connector and mea-

sure at the wire harness side.

• Start

• The voltage between 2# terminal

and grounding terminal
Standard value: System voltage

If normal, go to Step 5. If abnormal, go

to next step.

4. Check the engine control relay connector G2X-29. If abnormal, repair or replace it.

If normal, check the intermediate connector; if not, repair. If normal, check and repair the
wire harness between upstream oxygen sensor connector A20 (2# terminal) and the engine
control relay connector G2X-29 (1# terminal).

• Check if the power supply line is short circuit or open circuit.

5. Measure the executive voltage of engine ECU connector A46.

• Measure the terminal voltage of ECU.

• Start

• Voltage between 4# terminal and grounding terminal

Standard values:Less than 1V

If normal, go to Step 8. If abnormal, go to next step.

6. Check the engine ECU connector A46. If abnormal, repair or replace it. If normal, go to next
step.

7. Check the wire harness between upstream oxygen sensor connector A20 (4# terminal) and
engine ECU connector A46 (8# terminal).

• Check if the grounding is open or short.

If normal, replace the ECU. If abnormal, repair it.

8. Check the engine ECU connector A46. If abnormal, repair or replace it. If normal, go to next
step.

9. Check the wire harness between upstream oxygen sensor connector A20 (2# terminal) and
engine control relay connector G2X-29.

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NOTICE
Check the intermediate connector before checking the wire harness.

• Check if the power supply line is damaged.

If abnormal, repair it. If normal, go to next step.

9. Check the wire harness between upstream oxygen sensor connector A20 (4# terminal) and
engine ECU connector A46 (8# terminal).

• Check if the output line is damaged.

If abnormal, repair it. If normal, go to next step.

10. Check the symptom of malfunction. If it still exists, replace the engine ECU. If the malfunc-
tion disappears, it is an intermittent malfunction.
Procedure 23: Downstream Oxygen Sensor Heater System

Description:

• The power supply is transmitted from the engine control relay 88a to the power terminal (2#
terminal) of oxygen sensor heater of downstream cylinder.

• The power transistor of engine ECU (16# terminal) controls downstream oxygen sensor
heater (4# terminal).

Symptoms of Malfunction Possible Causes

The power supply of oxygen sensor heater for down- • Downstream oxygen sensor heater malfunction
stream is controlled by turning on/off the power tran- • Connector contact malfunction or open or short cir-
sistor of engine ECU. cuit of cable
• Engine-ECU malfunction

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Battery

EMS
main
relay
15A
Main
relay

Rear oxygen sensor

Shield layer
Shield layer

Diagnostic procedures:

1. Check the downstream oxygen sensor

connector A06. If abnormal, repair or re-
place it. If normal, go to next step.

2. Measure the executive resistance of

downstream oxygen sensor connector
A06.

• Remove the connector and mea-

sure at the sensor side.

• The resistance between 2# and

4# terminal
Standard value:11 - 18 Ω

If abnormal, replace it. If normal, go to

next step.

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3. Measure the executive voltage of down-

stream oxygen sensor connector A06.

• Remove the connector and mea-

sure the resistance at the wire
harness side.

• “ON” position power supply

• The voltage between 1# terminal

and grounding terminal
Standard value: System voltage

If normal, go to Step 5. If abnormal, go

to next step.

4. Check the engine control relay connector G2X-29. If abnormal, repair or replace it.

If normal, check the middle connector; if not, repair it firstly. If normal, check and repair the
wire harness between downstream oxygen sensor connector A06 (1# terminal) and the en-
gine control relay connector G2X-29.

• Check if the power supply line is short circuit or open circuit.

5. Measure the executive voltage of engine ECU connector A46.

• Measure the terminal voltage of ECU.

• Start

• Voltage between 116# terminal and grounding terminal

Standard values:Less than 1V

If normal, go to Step 8. If abnormal, go to next step.

6. Check the engine ECU connector A46. If abnormal, repair or replace it. If normal, go to next
step.

7. Check the wire harness between 2,3 #cylinder oxygen sensor connector A06 (4# terminal)
and engine ECU connector A46(16# terminal).

• Check if the grounding is open circuit or short circuit.

If normal, replace the ECU. If abnormal, repair it.

8. Check the engine ECU connector A46. If abnormal, repair or replace it. If normal, go to next
step.

9. Check the wire harness between downstream oxygen sensor connector A06 (2# terminal)
and engine control relay connector G2X-29.

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NOTICE
Check the intermediate connector before checking the wire harness.

• Check if the power supply line is damaged.

If abnormal, repair it. If normal, go to next step.

10 Check the wire harness between 2,3 # cylinder oxygen sensor connector A06 (4# terminal)
and engine ECU connector A46(16# terminal).

1) Check if the grounding is damaged.

If abnormal, repair it. If normal, go to next step.

11. Check the symptom of malfunction. If it still exists, replace the engine ECU. If the malfunc-
tion disappears, it is intermittent malfunction.
Procedure 24: EGR (Exhaust Gas Recycling) System

Battery

Main
relay

Main
relay

EGR
valve

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Description:

• The power supply is transmitted from the engine control relay (88a# terminal) to the EGR
valve (2# and 5# terminal).

• The power transistor is turned on under the action of engine ECU (6#,2#,15#and 22# termi-
nal) so as to make the current pass through the EGR valve (1#, 3#, 4# and 6# terminal).

Symptoms of Malfunction Possible Causes

The EGR valve controls the EGR action rate • Solenoid valve malfunction
as per the engine ECU signal. • Poor contact or open circuit or short circuit of wire har-
ness
• Engine ECU malfunction

Diagnostic procedures:

1. Check the EGR valve connector A39. If

abnormal, repair or replace it. If normal,
go to next step.

2. Check the EGR valve. If abnormal, re-

place it. If normal, go to next step.

3. Check the executive voltage of EGR

valve connector A39.

• Remove the connector and mea-

sure at the wire harness side.

• Start

• Measure the voltages between

2#,5# terminal and grounding
terminal
Standard value: System voltage

If normal, go to Step 5. If abnormal, go

to next step.

4. Check the engine control relay connec-

tor G2X-29.

If abnormal, repair or replace it.

If normal, check the intermediate con-

nector. If any malfunction, repair it first
and then check the wire harness be-
tween the engine control relay G2X-29
and the EGR valve connector A39 (2#
and 5# terminal).

• Check if the power supply line is

open or short circuit.

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5. Measure control voltage of engine ECU

connectorA46.

Remove the connector and measure the

resistance at the wire harness side.

Start

The voltage of 6#,2#,15#,22# and

grounding terminal
Standard value: System voltage

If normal, go to Step 7. If abnormal, go

to next step.

6. Check the engine ECU connector A46

If normal, check the wire harness be-

tween the EGR valve connector A39 and
the engine ECU connector A46.

1) Check the wire harness between

the EGR valve connector A39 (1#
terminal) and the engine ECU con-
nector A46 (6# terminal).

2) Check the wire harness between

the EGR valve connector A39 (3#
terminal) and the engine ECU con-
nector A46 (2# terminal).

3) Check the wire harness between the EGR valve connector A39 (4# terminal) and the engine
ECU connector A46 (22# terminal).

4) Check the wire harness between the EGR valve connector A39 (6# terminal) and the engine
ECU connector A46 (15# terminal).

• Check if the power supply line is open circuit or short circuit.

If abnormal, repair or replace it.

7. Check the engine ECU connector A46. If abnormal, repair or replace it. If normal, go to next
step.

8. Check the wire harness between the EGR valve connector A39 and the engine ECU connec-
tor A46.

1) Check the wire harness between the EGR valve connector A39 (1# terminal) and the
engine ECU connector A46 (6# terminal).

2) Check the wire harness between the EGR valve connector A39 (3# terminal) and the
engine ECU connector A46 (2# terminal).

3) Check the wire harness between the EGR valve connector A39 (4# terminal) and the
engine ECU connector A46 (22# terminal).

4) Check the wire harness between the EGR valve connector A39 (6# terminal) and the

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engine ECU connector A46 (15# terminal).

• Check if the output line is damaged.

If abnormal, repair or replace it.

8. Check the wire harness between the EGR valve connector A39 (2# and 5# terminal) and the
engine control relay connector G2X-29.

NOTICE
Check the intermediate connector before checking the wire harness.

• Check the damage of power line. If it is not damaged, change engine ECU. If the
power line is worn, repair it.
Procedure 25: Canister Control Solenoid Valve System

Battery

Main
relay

Main
relay
Carbon Canister Control Valve

Description:

• The power supply is transmitted from the engine control relay (88a# terminal) to carbon can-
ister control solenoid valve (1# terminal).

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• The power transistor is turned on under the action of engine ECU (25# terminal) to make the
current pass through the canister control solenoid valve (2# terminal).

Symptoms of Malfunction Possible Causes

The carbon canister control solenoid valve controls • Solenoid valve malfunction
the flow of canister air led into the carbon canister • Poor contact or open circuit or short circuit of wire
as per the engine ECU signal. harness
• Engine ECU malfunction

Diagnostic procedures:

1. Test the actuator with MUT-III.

Item 08: carbon canister control solenoid

valve
Standard: you shall hear the sound of
action and vacuum vibration.

If normal, it is intermittent malfunction. If

abnormal, go to next step.

2. Check carbon canister control solenoid

valve connector A13

If abnormal, repair or replace it. If nor-

mal, go to next step.

3. Measure the executive resistance of

carbon canister control solenoid valve
connector A13.

• Remove the connector and mea-

sure the resistance at the side of
solenoid valve.

• The resistance between 1# and

2# terminal
Standard: 30 - 34Ω (at 20° C)

If abnormal, replace it. If normal, go to

next step.

4. Measure the executive voltage of canister control solenoid valve connector A13.

• Remove the connector and measure at the wire harness side.

• Start

• The voltage between 1# terminal and grounding

Standard value: System voltage

If normal, go to Step 6. If abnormal, go to next step.

5. Check the engine control relay connector G2X-29.

If abnormal, repair or replace it.

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If normal, check the intermediate connector. If any malfunction, repair it first and then check
the wire harness between carbon canister control solenoid valve connector A13 (2# terminal)
and the engine control relay connector G2X-29 .

• Check if the power supply line is open circuit or short circuit.

6. Check the engine ECU connector A46.

If abnormal, repair or replace it. If normal, go to next step.

7. Measure the executive voltage of engine ECU connector A46.

• Remove the connector and measure at the wire harness side.

• "ON" position power supply

• Voltage between 25# terminal and grounding terminal

Standard value: System voltage

If normal, go to next step.

If abnormal, check and repair the wire harness between carbon canister control solenoid
valve connector A13 (2# terminal) and the engine ECU connector A46 (25# terminal).

• Check if the output line is open circuit or short circuit.

8. Check the wire harness between the canister control solenoid valve connector A13 (2# termi-
nal) and the engine ECU connector A46(25# terminal).

• Check if the output line is damaged.

If abnormal, repair it. If normal, go to next step.

9. Check the wire harness between carbon canister control solenoid valve connector A13 (1#
terminal) and the engine control relay G2X-29.

NOTICE
Check the intermediate connector C-116 before checking the wire harness.

• Check if the power supply line is damaged.

If abnormal, repair it. If normal, go to next step.

10. Test the actuator with MUT-III.

Item 08: carbon canister control solenoid valve

Standard: you shall hear the sound of action and vacuum vibration.

If normal, it is intermittent malfunction. If abnormal, replace the engine ECU.

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Procedure 26: Power Steering Hydraulic Pressure Switch System

Power
steering
switch

Symptoms of Malfunction Possible Causes

The switch signal of power steering pump load is • Power steering solenoid valve malfunction
transmitted to the engine ECU which then controls • Poor contact or open circuit or short circuit of wire
the rotary speed as per this input signal. harness
• Engine ECU malfunction

Diagnostic procedures:

1. Check data stream with MUT-III. Refer

to the data stream table.

Item B4: power steering hydraulic pres-

sure switch.

If normal, it is intermittent malfunction. If

abnormal, go to next step.

2. Check the power steering hydraulic

pressure switch connector AB07. If ab-
normal, repair or replace it. If normal, go
to next step.

3. Check the wire harness between the

power steering hydraulic pressure sen-
sor connector AB07 and the engine ECU
connector A47 (18# terminal).

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• Check if the power supply line is

damaged.

If abnormal, repair it. If normal, replace the

power steering hydraulic pressure switch.

Procedure 27: Engine Oil Control Valve System

Battery

Main
relay

Main
relay

Engine oil control valve

Description:

• The power supply is transmitted from the engine control relay (88a# terminal) to engine oil
control valve (2# terminal).

• The power transistor is turned on under the action of engine ECU (1# terminal) to make the
current pass to the oil control valve (1# terminal).

Symptoms of Malfunction Possible Causes

The engine oil control valve keeps the MIVEC sys- • Engine oil control valve malfunction
tem in the low-speed or high-speed mode by the • Poor contact or open circuit or short circuit of wire
camshaft and keeps consistent with engine ECU harness
signal.
• Engine ECU malfunction

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Diagnostic procedures:

1. Check engine oil control valve connector

A38. If abnormal, repair or replace it. If
normal, go to next step.

2. Measure the executive resistance of oil

control valve connector A38.

• Remove the connector and mea-

sure at the side of control valve.

• The resistance between 1# and

2# terminal
Standard value: 6.9 – 7.9Ω (at 20° C)

If abnormal, replace it. If normal, go to

next step.

3. Measure the executive voltage of engine

oil control valve connector A38.

• Remove the connector and mea-

sure the resistance at the wire
harness side.

• Power supply “ON” position.

• The voltage between 2# terminal

and grounding
Standard value: System voltage

If normal, go to Step 5. If abnormal, go

to next step.

4. Check the engine control relay connec-

tor G2X-29.

If normal, check the intermediate con-

nector. If any malfunction, repair it first ;
if normal, check and repair the wire har-
ness between engine oil control valve
connector A38 (2# terminal) and the en-
gine control relay connector G2X-29.

• Check if the power supply line is

open circuit or short circuit.

If abnormal, repair or replace it.

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5. Measure the executive voltage of engine

ECU connector A49.

• Remove the connector and mea-

sure at the wire harness side.

• “ON” position power supply

• The voltage between 1# terminal

and grounding
Standard value: System voltage

If normal, go to Step 7. If abnormal, go

to next step.

6. Check the engine ECU connector A49.

If normal, check and repair the wire har-

ness between engine oil control valve
connector A38 (1# terminal) and the en-
gine ECU connector A49 (1# terminal).

• Check if the output line is open

or short.

If abnormal, repair or replace it.

7. Check the engine ECU connector A49. If

abnormal, repair or replace it. If normal,
go to next step.

8. Check the wire harness between the oil

control valve connector A38 (1# termi-
nal) and the engine ECU connector A49
(1# terminal).

• Check if the output line is dam-

aged.

If abnormal, repair it. If normal, go to

next step.

9. Check the engine control relay connec-

tor B-15X. If abnormal, repair or replace
it. If normal, go to next step.

10. Check the wire harness between engine

oil control valve connector A38 (2# ter-
minal) and the engine control relay con-
nector B-15X.

NOTICE
Check the intermediate connector before
checking the wire harness.

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• Check if the power supply line is

damaged.

If abnormal, repair it. If normal, go to

next step.

11. Check the symptom of malfunction. If it

still exists, replace the engine ECU. If it
disappears, it is intermittent malfunction.

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2. Ignition System
2.1 Overview

Four ignition coils with built-in power transistors are in the system, which apply on each cylinder
respectively. The interruption of the current at the preliminary side of the ignition coil will generate
high voltage electricity at the secondary side of the ignition coil. The high voltage generated will
be applied to the spark plug to generate spark. The engine ECU alternately turns on and off the
two power transistors inside the ignition coil.Thus, the primary current inside the ignition coils is
turned on and off so as to ignite for each cylinder in the order of 1—3—4—2.

The engine ECU determines the controlled ignition coil as per the signals sent out from the cam-
shaft position sensor and crankshaft angle sensor. It also detects the crankshaft position thus to
provide the optimum ignition timing for engine operating. When the engine is cold or operating at
high elevation, the ignition timing must be advanced slightly so as to ensure the optimum perfor-
mance in the running conditions. In addition, when knock occurs, the ignition timing is greatly de-
layed till knock disappears.

System Diagram

Ignition switch
Battery
Air flow sensor

Atmospheric pressure sensor

Intake temperature sensor

Water temperature sensor

Accelerator pedal position sensor

Camshaft position sensor

Engine-ECU
Crankshaft angle sensor

Ignition switch - ST Ignition coil

Knock sensor

Vehicle speed sensor (manual)

Limit switch (auto)

Spark plug

Cylinder

Ignition coil specification

Item Specification
Ignition coil Moulded four coil

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Spark plug gap

Item Standard value Limit value

Spark gap mm 0.7-0.8 1.2

Spark plug specification

Item Specification
NGK LZFR6AI

Special tool

Tool Number Name Usage

MD998773 Knock sensor wrench Remove and install knock sensor

Ignition coil (built-in power transistor) Inspection

Check the conductivity of primary coil and

power transistor

NOTICE
• Use analog ohmmeter

• Connect the negative pole (-) of mul-

timeter to 1# terminal

NOTICE
The test shall be completed rapidly (with-
in 10 seconds), so as to avoid coil burn
and power transistor damage.

Connect and disconnect the 4.5 - 9.0V bat-

tery between 2# and 3# terminal and observe
if the ohmmeter pointer changes continu-
ously.

4.5-9.0V power Conductivity be-

supply between tween 1–2
2–3
When current passes Continuous
through
When current is cut off Discontinuous

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Check the secondary coil:

1. Remove the ignition coil connector.

2. Remove the ignition coil and install a new spark plug on it.

3. Check the ignition coil connector.

4. Grounding at the side of spark plug electrode to operate the engine.

5. Check the spark between the spark plug electrodes.

6. If no spark is generated, replace with a new ignition coil and then check the spark.

7. If spark can be generated with the new spark coil, replace the old ignition coil. If still no
spark, check the ignition circuit.

Inspection and cleaning of the spark plug

1. Remove the spark plug.

NOTICE
• Do not attempt to adjust the central
electrode gap of iridium.
Iraurita • Cleaning with tools should be com-
electrodes pleted within 20 seconds and do not
use wire brush.

2. Check the spark plug gap. If it is not

within the standard range, replace the
spark plug.
Standard Range: 0.7 - 0.8 mm

Limit Value: 1.2 mm

NOTICE
Prevent the impurities entering into the
cylinder.

3. Clean the spark plug hole on the engine.

4. Install the spark plug.

Inspection of the camshaft position sensor

Refer to the EFI System Service Manual – Troubleshooting.

Inspection of the crankshaft angle sensor

Refer to the EFI System Service Manual – Troubleshooting.

Inspection of the knock sensor

Refer to the EFI System Service Manual – Troubleshooting.

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Disassembly & Installation

Disassemble Procedure
1 Ignition coil connector
2 Ignition coil
3 Spark plug

Disassembly & Installation

Disassemble Procedure
1 Camshaft position sensor
connector
2 Camshaft position sensor
3 O-Ring

Disassembly & Installation

Disassemble Procedure
1 Timing belt lower cover
2 Crankshaft position sensor

Disassembly & Installation

NOTICE
Do not let the knock sensor drops down or impacts with other components. If above-
mentioned cases are happened, please replace the knock sensor.

Disassemble Procedure
1 Knock sensor connector
2 Knock sensor clamp
3 Wire harness clamp
4 Intake manifold cover
5 Knock sensor
6 Knock sensor clamp

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3. Charging system
3.1 Overview

The charging system utilizes the electric energy output from the alternating- current generator to
charge the battery so as to keep a constant charging under different loads.

Voltage

About
Time

Action Principle

Rotation of the excited field coil generates an AC voltage in the stator. This alternating current is
rectified through the diodes to DC voltage with its waveform illustrated on the left figure. The aver-
age output voltage fluctuates slightly with the alternator load condition.

When the ignition switch is turned on, current flows in the field coil and initial excitation of the field
coil occurs. When the stator coil begins to generate power after the engine is started, the field
coil is excited by the output current of the stator coil. The alternator output power rises as the field
current increases and it falls as the field current decreases. When the battery voltage (alternator
S terminal voltage) reaches a regulated voltage of approximately 14.4V, the field current is cut off.
When the battery voltage drops below the regulated voltage, the voltage regulator regulates the
output voltage to keep constant level by controlling the field current.

In addition, when the field current is constant, the alternator output voltage rises as the engine
speed increases.

System Diagram

Stator coil

Engine ECU

Field coil

Voltage
regulator Ignition switch
Battery
Charging indicator light

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Alternator specification

Item Specification
Type Battery voltage check type
Rated output power V/A 12/110

Voltage regulator Built-in electronic regulation type

3.2 Service specifications

Standard
Item Limit Value
Value
Voltage drop of alternator output line (30A) V Maximum 0.3
Voltage regulation range -20℃ 14.2 ~ 15.4
Operating temperature of volt-
age regulator 20℃ 13.9 ~ 14.9
60℃ 13.4 ~ 14.6
80℃ 13.1 ~ 14.5
Output current 70% of rated output current

3.3 Special tools

Tools Number Name Purpose

MB991955 MUT-III and attachment Check when idling
A: MB991824 A: MUT-III tester
NOTICE
B: MB991827 B: MUT-III USB cable
C: MB991910 C: MUT-III main cable A The MUT-III main cable A can be
D: MB991911 (for vehicles with com- used to send an analog vehicle
E: MB991825 munication connector) speed signal, but cable B cannot.
F: MB991826 D: MUT-III main cable
B (for vehicles without
communication connec-
tor)
E: MUT-III test connec-
tor
F: MUT-III trigger cable

MB991519 Alternator test cable Check the alternator S terminal volt-

age

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3.4 Voltage drop test of alternator output line

Ammeter (tong-type)
Generator

Voltmeter (digital)

Battery
Terminal B

This test is intended to test whether the cable (including fuse) between the alternator terminal B
and battery positive (+) terminal is normal.

1. Before the test, always be sure to check the following:

1) Alternator installation status.

2) Alternator drive belt tension. (Refer to Servicing and Adjusting Order)

3) Fuse status.

4) Abnormal noise from the alternator when the engine is operating.

2. Turn the ignition switch to “OFF” position.

3. Disconnect the battery F negative cable.

4. Connect a tong-type DC ammeter (range: 0-150A) to the output line of alternator B terminal.

NOTICE
With poor connection between “B” terminal and output line, problem of output current
drop cannot be found by means of removing the alternator output line and reconnecting
the ammeter.

5. Connect a digital voltmeter between the alternator terminal B and battery positive (+) termi-
nal. (Positive (+) wire of voltmeter is connected to terminal B and the negative (-) wire is con-
nected to battery positive (+) terminal.)

6. Reconnect the battery negative cable.

7. Connect the MUT-III tester (display the engine speed).

8. Keep the engine hood open.

9. Start the engine.

10. At 2500 rpm/min engine speed, adjust the alternator load by turning on or off the headlight
and other lights to make the ammeter pointer point at a value a bit higher than 30A. Slowly

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reduce the engine speed to make the ammeter pointer point at 30A and then read the value dis-
played on the voltmeter. Limit value: max. 0.3V.

NOTICE
When the alternator output power is too high to reduce the indicated value to 30A on the
ammeter, adjust it to 40A and read the value displayed on the voltmeter. Then, the limit
value is became maximum value 0.4 V.
11. If the displayed value is higher than the limit value, the alternator output line may be poor.
Therefore, check the cable (including fuse) between the alternator terminal B and battery
positive (+) terminal. If such abnormalities as loose terminal or discolored cable due to over-
heat are found, repair it first and then make test.
12. Make engine idle running after the test is completed.
13. Turn off all the lights.
14. Power supply OFF
15. Remove the MUT-III.
16. Remove the battery negative cable.
17. Remove the ammeter and voltmeter used for test.

18. Connect the battery negative cable.

3.5 Output current test

Load

Voltmeter Ammeter (tong-type)

Combination instrument
Ignition switch Charging
-IG warning light

Generator

Engine-ECU
Battery

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The purpose of test is to check whether the alternator output current is normal.

1. Before the test, please check the following:

• Alternator installation status.

• Battery status (Refer to Battery).

NOTICE
The battery should be slightly discharged. A fully-charged battery is unable to pro-
vide sufficient load needed for an accurate test.

• Drive belt tension. (Refer to Servicing and Adjusting Order)

• Fuse status.

• Abnormal noise from the alternator while the engine is operating.

2. Power supply OFF

3. Remove the battery negative cable.

4. Connect a DC tong-type ammeter (range: 0-150A) to the output line of alternator B terminal.

NOTICE
With poor connection between “B” terminal and output line, problem of output cur-
rent drop cannot be found by means of removing the alternator output line and re-
connecting the ammeter.

5. Connect a 0-20V voltmeter used for test between terminal B and grounding. (Positive (+)
wire of voltmeter is connected to terminal B; negative (-) wire is connected to grounding.)

6. Connect the battery negative cable.

7. Connect the MUT-III tester (display the engine speed).

8. Keep the engine hood open.

9. Check if the reading on the voltmeter is same as the battery voltage.

NOTICE
If the voltage is 0 V, the cable between alternator terminal B and battery positive (+)
terminal may be disconnected or the fuse may be burnt.

10. Turn on the lighting switch and the headlight switch, and start the engine.

11. Set the headlight to the high beam and turn the heater blower switch to big volume position,
increase the engine speed to 2500 r/min and read the maximum output current value dis-
played on the ammeter.
Limit value: 70% of rated output current value

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NOTICE
• For rated output current value, refer to specifications on alternator nameplate.
• Because charging current from the battery will soon drop after the engine is
started, you must read the maximum current value as quickly as possible.
• The output current value varies with electrical load and temperature of alterna-
tor body.
• If the electrical load of the vehicle is small while testing, the specified output
current may not be able to obtain even though the alternator is normal. In such
cases, increase the electrical load by turning the headlight on to discharge the
battery or by using the lighting system in another vehicle, and then test again.
• The specified output current may also not be able to obtain if the temperature
of the alternator body or the ambient temperature is too high. In such cases,
cool the alternator and then test again.

12. The reading on the ammeter should be greater than the limit value. If it is lower than the limit
value and the alternator output line is normal, remove the alternator from engine and check
it.
13. Make engine idle running after the test is completed.
14. Power supply OFF.
15. Remove the MUT-III tester.
16. Remove the battery negative cable.
17. Remove the ammeter and voltmeter used for test.
18. Connect the battery negative cable.
3.6 Voltage regulation test

Load
Ammeter (tong-type)

Combination instrument

Ignition switch Charging warning

light

Black

Generator

Blue
Engine-ECU
Red Yellow
Battery

Voltmeter (digital)

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The purpose of test is to check whether the voltage regulator can properly control the alternator
output voltage.

1. Before the test, please check the following:

• Alternator installation status.

• Battery status. (Refer to Battery)

• Drive belt tension. (Refer to Servicing and Adjusting Order)

• Fuse status.

• Abnormal noise from the alternator while the engine is running.

2. Power supply OFF

3. Remove battery negative cable.

4. Connect the digital voltmeter between alternator S terminal and grounding with alternator
test cable (MB991519) by special tool (Positive (+) wire of voltmeter is connected to terminal
B and the negative (-) wire is connected to grounding or battery negative electrode.)

5. Connect a tong-type DC ammeter (range: 0-150A) to output line of alternator B terminal.

NOTICE
With poor connection between “B” terminal and output line, problem of output cur-
rent drop cannot be found by means of removing the alternator output line and re-
connecting the ammeter.

6. Reconnect the battery negative cable.

7. Connect the MUT-III tester (display the engine speed).

8. At ON gear, check if the reading on the voltmeter is same as battery voltage.

NOTICE
If the voltage is 0 V, the cable between the alternator terminal B and the positive (+)
battery terminal may be disconnected or the fuse may be burnt.

9. Turn off all lights and attachments.

10. Start the engine.

11. Increase engine speed to 2500 r/min.

12. Read the value displayed on the voltmeter when the alternator output current reduces to 10A
or less.

13. If reading of voltage value is same as the value in the voltage regulation table, the voltage
regulator is working normally.

14. Make engine idle running after the test is completed.

15. Power supply OFF.

16. Remove the MUT-III tester.

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17. Remove battery negative cable.

18. Remove the ammeter and voltmeter used for test.

19. Connect the alternator output line to the alternator B terminal.

20. Remove the special tool and reset the connector.

21. Connect the battery negative cable.

Voltage regulation standard value:

Operating Temperature of Voltage

Check Terminal Standard Value
Regulator (° C)
“S” -20 14.2 - 15.4
20 13.9 - 14.9
60 13.4 - 14.6
80 13.1 - 14.5

Disassembly & Installation

Disassemble procedure
1 Oxygen sensor connec-
tor
2 Oxygen sensor connec-
tor clamp
3 A/C compressor as-
sembly connector
4 A/C compressor con-
nector clamp
5 Alternator connector
6 Alternator terminal
7 Connector bracket
8 Cable clamp
9 Alternator assembly
● Timing belt lower cover
10 Alternator assembling
bracket

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Disassembly & Installation

Disassemble procedure
1. Front bracket assembly
2. Alternator wheel
3. Rotor
4. Rear bearing
5. Rear clamp holder
6. Front bearing
7. Front bracket
8. Stator
9. Fixing plate
10. Adjuster
11. Electric brush
12. Rubber gasket
13. Rectifier
14. Rear bracket

1. Disassemble front bracket assembly

NOTICE
Do not insert screwdriver too deep in or-
der to avoid damage stator core.

Insert flat-tipped screwdriver between front

bracket and stator core and pry downwards
to seperate them.

2. Disassemble the pulley

NOTICE
Do not damage the rotor.

With the pulley side surface facing up, hold

the rotor in a bench screw and disassemble
the pulley.

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Rectifier Weldment 3. Disassemble the stator & regulator as-

assembly sembly

NOTICE
• After unsoldering in four seconds
with 180 - 250W electric soldering
iron. Do not weld for long time as the
Weldment heat of the electric iron may transmit
to the diodes
• Do not pull the leads of diodes with
too much force

1). Unsolder the stator from the rectifier as-

sembly.

2). Disassemble the rectifier from regulator,

unsolder all the soldered points of recti-
fier.

Tips for assembly operation 1. Install the regulator assembly

After Installing the regulator assembly prop-

erly, push in the brush and insert metal wire
into the rear bracket hole to hold the brush.
Metal wire
NOTICE
Insert metal wire to hold the brush and
replace rotor easily.

Rear bracket

Brush

Line

2. Install the rotor

Disassemble brush wire after installing rotor.

Metal wire

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Check:

Rotor

1. Measure the resistance between two

sliding vanes of stator coil and check the
conductivity between them.
Standard values: 3 - 5 Ω

2. Check the conductivity between sliding

vane and the iron core. If it is conduc-
tive, the rotor should be replaced.

Stator

1. Check the conductivity between the

coil heads. If it is not conductive, stator
should be replaced.

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2. Check the conductivity between the coil

and the center. If not conductive, replace
the stator.

Rectifier assembly

1. Check the conductivity between the ter-

minals connected with each stator coil
and the cooling fin (+). If conductive, the
diodes may be short-circuited. Replace
the rectifier assembly.

2. Check the conductivity between the ter-

minals connected with each stator coil
and the cooling fin (+). If conductive, the
diodes may be short-circuited. Replace
the rectifier assembly.

3. Connect the ammeter to two ends of

each of the six diode to check if they are
conductive.

If not conductive in both two directions,

the diodes must have been damaged.
Replace the radiator assembly.

Brush

1. Measure the protrusion length of the

brush. If it is less than the standard
Extend length
length, replace the brush.
Standard: ≥ 2 mm

2. Unsolder the brush head before remov-

al.

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Weldment 3. In case of new brush installation, weld

brush head when brush is properly
pressed into brush holder as shown in
the figure.

4 Starting System
4.1 Overview

If the ignition switch is turned to “START” position, current flows in the coil inside magnetic switch
to attract iron core. When the iron core is attracted, the lever connected to the iron core is actu-
ated to engage the starter clutch. On the other hand, attracted iron core will turn on the magnetic
switch, and allow the B and M terminal to conduct. Thus, current flows engage the starting motor.
When the ignition switch is returned to “ON” position after starting the engine, the starter clutch is
disengaged from the ring gear.

An overrunning clutch is provided between pinion and armature shaft to prevent damage to the
starter.

Starter Specification

Item Specification
Type Reduction drive with planetary gear
Rated output power kW/V 1.4/12
Number of teeth 8

Maintenance Specification

Item Standard Value Limit Value

Pinion gap mm 0.5 - 2.0 -
Redirector stand-out mm 0.05 0.1
Redirector diameter mm 29.4 28.8
Recessed depth mm 0.5 0.2

Disassembly and Installation

Operations before disassembly : Operations after assembly :

Disassemble intake pipe • Install intake pipe
• Fill the transmission oil

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Disassemble proce-
dure
1. Oil pipe
2. O-ring
3. Radiator pipe clamp
4. Water supply pipe
5. Water return pipe
6. ATF heater
7. Starter cover
8. Wire harness clamp
9. Starter connector
10. Starter terminal
11. Starter
12. Starter cover bracket

<<1>> ATF Heater Disassembly (A/T FLU-

ID COOLER)
AFT heater Disassemble the ATF heater (A/T fluid cooler)
with water pipe from the transmission front
limit bracket. Move the assembly towards
the battery and support it properly in order to
Battery avoid interference with the disassembly and
installation of the starter assembly.

<<2>>Starter Cover Disassembly

Disassemble starter cover bolt and disas-

semble starter cover from the side for install-
ing ATF.

<<3>> Disassembly & Installation of Wire

Harness Clamp/Connector/Starter Termi-
nal

Disassembly the starter mounting bolt and

loosen the wire harness clamp, starter con-
nector and starter terminal.

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Clutch master <<4>> Disassembly of Clutch Oil Pump

cylinder <M/T>

Disassemble clutch oil pump screw and place

clutch oil pipe in the place where no interfer-
ence will be caused to starter disassembly.

<<5>> Disassembly & Installation of Start-

er Assembly

Disassemble the starter assembly from ve-

hicle.

<<6>> Disassembly & Installation of Start-

er Assembly

Disassemble the starter assembly in the po-

sition where the ATF heater (A/T fluid cooler)
is installed.

Check Starter Motor

Pinion Gap Adjustment

1. Disconnect the field coil from the M ter-

minal of magnetic switch.
Switch
2. Connect 12V battery between S terminal
and M terminal.
Battery
3. Turn the ignition switch to “ON” and
Starting make pinion disconnect.
motor Line
NOTICE
The test must be conducted quickly (
less than 10 seconds) to prevent coil be-
ing burnt.

4. Check gap between pinion and stopper

Stopper with feeler gauge.

Standard value: 0.5 - 2.0 mm

Pinion

Pinion gap

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5. If pinion gap is out of specification, ad-

just it by adding or removing gaskets
between magnetic switch and front
bracket.

Magnetic Switch Pull-in Test

Switch 1. Disconnect field coil from M terminal of
magnetic switch.
Battery 2. Connect 12V battery between S terminal
and M terminal.
Starting
Line
motor NOTICE
The test must be conducted quickly (
less than 10 seconds) to prevent the coil
being burnt.

3. If pinion moves out, pull-in coil is good.

If not, replace magnetic coil.

Magnetic Switch Hold-in Test

Switch 1. Disconnect field coil from M terminal of
magnetic switch.
Battery 2. Connect 12V battery between S terminal
and M terminal.
Starting
motor Line
NOTICE
The test must be conducted quickly (
less than 10 seconds) to prevent the coil
being burnt.

3. Pull pinion to position of stopper by your

hand.

4. If pinion moves out, it is normal. If pinion

moves in, hold-in coil circuit is open, and
replace magnetic switch.

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Free Running Test

Ammeter
1. Connect starting motor to fully-charged
12V battery as shown in the figure.
Variable resistance 2. Connect ammeter and variable resis-
tance to battery positive terminal and
starting motor terminal.
Battery
Starting 3. Connect voltmeter across the starting
motor Voltmeter motor.

4. Rotate variable resistance to the full re-

sistance.

5. Connect battery negative terminal to

starting motor body.

6. Adjust variable resistance until voltage

shown on the voltmeter is 11 V.

7. Confirm if the maximum current is within

specified range and if the starting motor
rotates freely.
Current: Max. 90 Amps

Magnetic Switch Rotation Test

Switch
1. Disconnect field coil from M terminal of
magnetic switch.
Battery 2. Connect 12V battery between the body
and M terminal.
Starting
motor Line
NOTICE
The test must be conducted quickly (
less than 10 seconds) to prevent coil be-
ing burnt.

3. Push pinion to extend and release.

If pinion returns to its original position
quickly, it works normally; if it cannot, re-
place the field coil.

CAUTION
Be careful of your fingers when pushing
the pinion.

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Disassembly and Installation

Disassembly Procedure

1. Screw 2.Solenoid switch 3. Screw 4. Bolt 5.Rear bracket 6.Brush Holder

7. Rear bearing 8. Armature. 9. Magnetic assembly 10. Washer A 11. Washer B

12. Plate 13. Planet gear 14. Rod 15. Snap spring 16. Thrust ring 17.Overrunning Clutch

18. Internal gear 19. Planet gear shaft 20. Front bracket

Magnetic
S terminal <<1>> Solenoid Valve Disassemblyl
switch

B terminal
NOTICE
Do not clamp magnetic assembly with
pliers.
M terminal
Field coil head
Disassemble lead from M terminal of mag-
netic switch.

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<<2>> Snap spring & Thrust ring Disas-

semblyl

1). Disassemble Thrust ring with suitable

Socket wrench socket wrench which shall be turned to-
wards the pinion side.
Check ring Pinion

Overrunning Clutch

2). Disassemble the snap spring with snap

Snap spring
Snap spring pliers spring pliers and then Thrust ring and
Pinion
overrunning clutch.
Overrunning Clutch

Starting Motor Parts Cleaning

1. Do not immerse parts in cleaning sol- 2. Do not immerse drive parts in cleaning
vent to clean them, and the insulation of solvent. Overrunning clutch is lubricated
magnet yoke, field coil assembly or rotor before delivery and solvent will wash
will be damaged. off lubrication on the clutch when it is
cleaned in cleaning solvent.

<<1>> Thrust ring&Snap Spring Assembly

With suitable tool, pull Thrust ring towards the

direction of snap spring across Thrust ring
Check ring
Overrunning Clutch
Check ring

Snap spring

Rotor

1. Place rotor on a pair of V blocks and

check diameter runout by a dial indica-
tor.
Standard value: ≤ 0.05 mm

Limit value: 0.1 mm

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2. Measure rotor diameter.

Standard value: 29.4 mm

Limit value: 28.8 mm

3. Check immersion depth of mica between

rectiblock segments.
Depth
Rectiblock Mica Standard value e: 0.5 mm

Limit value t: 0.2 mm

Brush Holder

Push the brush into the brush holder and be

sure the spring on the brush is normal; other-
wise, replace the brush holder.

Overrunning Clutch

1. Confirm if pinion rotates smoothly to the

right but not to the left.

2. Check the pinion for wear or damage.

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 BYD S6, S6A, S6K Service Manual

Brush

1. Check roughness of contact surface

between brush and communtator as
well as the length of brush. If the brush
holder length is less than the limit value,
Length of the brush should be replaced.
brush
Limit value: 7.0 mm

2. In modifying the contact surface of brush

or replacing a new brush, wind a piece of
abrasive paper around the rotor.

Armature Coil

1. Check the rotor coil for short circuit.

2. Put the rotor on the growler.

NOTICE
Clean the rotor surface completely and
then check it.

3. Put the thin iron sheet on the rotor and

keep it in parallel with the central shaft
of rotor. Slowly rotate the rotor and ob-
serve the thin iron sheet.

If the iron sheet is not attracted and no

vibration, the rotor is normal.

4. Check the insulation between the recti-

block and the rotor iron core. If it is not
conductive, it is normal.

5. Check the rotor coil for open circuit.

Check conduction between rectiblocks,
if it is conductive, it is normal.

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Section 3 BYD TB10 Engine system, do not remove any parts or its
connectors from its mounting position
Management System Service so as to avoid unexpected damage
Manual and prevent foreign matters such as
moisture and greasy dirt from entering
1. EFI Service Notice the connector;

• Be sure to turn off the ignition switch

1.1 General Service Notice
before you connect or disconnect the
• You are only allowed to check the EFI connectors; otherwise, damage may be
system with a digital multimeter; caused to the electronic elements;

• Please use the quality parts for service; • Keep the ECU temperature lower than
otherwise, the EFI system may not work 80° C in simulating the hot condition of
normally; malfunction or other service operations
which may cause a temperature rise;
• Only unleaded gasoline can be used
during service; • Before servicing the fuel system or
electrical system, please disconnect
• Please comply with the service the battery, do not smoke, there is no
procedures; open flame, and have fire extinguishing
equipment;
• No one is allowed to disassemble the
parts of EFI system during service; • The EFI system has a much higher fuel
supply pressure (about 600kPa), so
• Handle the electronic elements (ECU,
high-pressure resistant fuel pipes are
sensor, etc.) very carefully during
used for all the fuel pipelines; Even if the
service, to avoid dropping to the ground;
engine is not running, the fuel pressure
• Build up an environmental awareness is much higher in the oil line. Therefore,
and treat the wastes produced during do not easily disassemble the fuel pipes
service effectively. during service; if the fuel system requires
service, please release the pressure of
1.2 Notice during Service the fuel system in the following method
before removing the fuel pipes: remove
• Before servicing in the engine
the fuel pump relay, start the engine and
compartment, shut down the engine, pull
let it idle, until the engine flames out
out the ignition key, pull up the brake
automatically. Only professional service
handle, shift to neutral position or turn
technicians are allowed to disassemble
the shift lever to P position, and keep
the pipeline and replace the fuel filter at
children away from the engine;
a well-ventilated place;
• Avoid short circuit of the electrical
• Do not power on the electric fuel pump
system, especially battery short circuit;
when you remove it from the fuel tank,
beware of battery explosion;
as it may cause electric spark or even
• If the service must be carried out when fire;
the engine is starting or running, the risk
• You are not allowed to conduct a running
will be greater; please be careful and
test to the fuel pump when it is dry or
avoid injury and even death caused by
in water; otherwise, its service life may
rotating parts such as transmission belt,
be shortened. In addition, its positive
generator and radiator fan, and high-
and negative poles shall be properly
voltage ignition system; do not touch the
connected;
wires of the ignition system;
• To check the ignition system, spark-over
• To ensure normal working of the EFI
test can be taken only when necessary.

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 BYD S6, S6A, S6K Service Manual

Such a test shall be completed in a 2. Tool name: EFI System Adapter

short time and the throttle valve cannot
be opened during test; otherwise, it Function: Check the electrical signal
may cause a lot of unburned gasoline of each pin of the ECU, check the line
entering the bleeding pipe and damage condition, etc.
the three-way catalyst;

• Just install the electronic throttle body in

place since the idle speed is adjusted by
the EFI system and doesn’t require any
manual adjustment;

• The positive and negative terminals of

battery shall be properly connected so
as to avoid any damage to electronic
components. Negative grounding is
adopted for this system;

• Do not ground the positive pole of the

battery, or else the fuse may be blown
out, 3. Tool name: Ignition Timing Lamp
• resulting in power failure of the electrical Function: Check engine ignition timing.
system or damage of electronic
components;

• Do not remove the battery when the

engine is running;

• Remove the positive and negative cable

of battery as well as the ECU before
electric welding on the car;

• Do not check the electric input/output

signals of parts by piercing the cable
sheath.
1.3 Recommended Service Tools

1. Tool name: BYD ED400 Diagnostic

Tester 4. Tool name: Digital Multimeter

Function: Read/clear EFI system DTC, Function: Check the voltage, current and
check data stream, part operation test, resistance of the EFI system.
etc.;

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 BYD S6, S6A, S6K Service Manual

5. Tool name: Vacuum Meter 8. Tool name: Exhaust Gas Analyzer

Function: Check the pressure in the Function: Check the exhaust emission,
intake manifold. to help EFI system troubleshooting.

6. Tool name: Cylinder Pressure Gauge

Function: Check the pressure of each 9. Tool name: Fuel Injector Cleaning
cylinder. Analyzer

Function: Analyze the cleaning of fuel

injector.

7. Tool name: Fuel Pressure Gauge

Function: Check the pressure of fuel

system, and judge the working condition
of fuel pump in the fuel system.

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2. TB10 System Overview (temperature, pressure, etc.), and convert

into corresponding electrical signals; ECU
2.1 Basic Principles is used to receive input signals from the
sensor, calculate and process according
2.1.1 System Overview
to set procedure, generate corresponding
TB10 Engine Management System control signal and output to the power
drive circuit, which will run the engine in
EMS mainly consists of the sensor, controller accordance with the established control
(ECU), and actuator, which will control the strategy by driving the respective actuators to
air intake amount, fuel injection quantity and perform different actions; meanwhile, the fault
ignition advance angle when the engine is diagnostic system for the ECU monitors every
running. The basic structure is shown in Fig. component or control function in the system;
2.1. once the fault is detected and confirmed, the
fault code is stored, and the “limp home”
function is called; when the fault has been
Sensor
Diagnosis
ECU Diagnosis
eliminated, the normal value is restored.

TB10 engine electronic control management

system features direct injection, exhaust
Engine
turbocharger control, and torque-based
control strategy. The main purpose of the
torque-based control strategy is to link a
Fig. 2.1 Components of Engine Electronic large number of different control objectives
Control System to achieve perfect power allocation and
application, making the car have excellent
In the engine electronic control system, driving performance and energy efficiency.
the sensor is used as the input part
to measure various physical signals The structure of TB10 engine electronic
control system is shown in Fig. 2.2.

Air filter Turbocharger - roller Intake air Camshaft OCV

Electronic Ignition coil Oxygen sensor
throttle body temperature/pres phase electromagnetic
sure sensor sensor valve

Turbocharger air
circulating valve

Three-way catalyst
Carbon canister
electromagnetic valve

Turbocharger - turbine

Carbon
canister
Supercharging limit
electromagnetic valve

Crankshaft Knock sensor Water

Low pressure High pressure High pressure Fuel pressure High pressure position temperature
fuel pump and fuel pump fuel rail sensor fuel injector sensor sensor
control module

Fig. 2.2 Structure of TB10 Engine Electronic Control System

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 BYD S6, S6A, S6K Service Manual

TB10 engine electronic control system mainly 7. variable intake valve timing control;
consists of:
8. Exhaust gas turbocharger regulation and
Electronic Control Unit (ECU) control;
Electronic Throttle Body
9. Cycle control of intake boost limit;
OCV electromagnetic valve
High Pressure Fuel Injector 10. High pressure oil pump mechanical
supercharger and conditioning system
Intake Pressure / Temperature Sensor ensures high pressure common rail
Low Pressure Fuel Pump and Module hydraulic;

Coolant Temperature Sensor 11. Electronic control pump cooling system;

High Pressure Oil Pressure Sensor
12. Emission control;
High Pressure Oil Pump
High Pressure Fuel Rail 13. Cold three-way catalyst heats up rapidly;

Camshaft Phase Sensor 14. Carbon canister purge control;

Knock Sensor 15. Idle speed adaptive control and speed
Speed Sensor limit protection;
Carbon Canister Electromagnetic Valve 16. Limp home;
Oxygen Sensor 17. CAN line self-diagnosis;
Ignition Coil
18. Support CAN communication of the car;
2.1.1.1 Turbocharger Air Circulation Valve
Boost Pressure Limiting Valve 19. Exhaust temperature control;
TB10 EMS is an electronically-operated 20. Cruise control;
gasoline engine control system, which
provides many control characteristics related 21. Mileage accumulation and memory;
to operator and vehicle or equipment. This 22. Engine temperature protection;
system combines the open-loop and closed-
loop (feedback) control modes to provide 23. Torque / speed compensation
various control signals for running the engine.
2.1.1.2 Additional functions
Main features:
Theft protection function features
Basic management functions physical model collaboration with the engine, and cooperates
applied engine with KEYLESS system.
1. Torque-based system structure; 2.1.1.3 On-board diagnosis (OBD II)

2. Cylinder load is determined by the intake Complete a series of OBD II functions, used
air pressure sensor; for diagnostic functions of management
system.
3. Improved air-mix control function in both
static and dynamic state; 2.1.2 Torque structure

4. λ closed-loop Control; TB10 system based on torque control:

5. Direct fuel injection in the cylinder in In the torque-controlled TB10 system, all
sequence; the internal and external demands for the
engine are defined as the torque or efficiency
6. Ignition timing, including knock control in requirements of the engine, as shown in
cylinder order; Fig. 2.3. The requirements of engine are

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 BYD S6, S6A, S6K Service Manual

converted to torque or efficiency control During engine matching, due to the variable
variables, which then will be processed in the independence of torque-controlled system,
central torque demand coordinator module. only the engine data are used to match
TB10 system can sort these conflicting the engine characteristic curve and pulse
requirements by priority, carry out the most spectrum, and won’t interfere with other
important one and obtain such parameters functions and variables, which will avoid
as the required fuel injection time and ignition repeated calibration, simplify the matching
timing by the torque converting module. The process and reduce the cost of matching.
execution of this control variable has no
effect to other variables, which is the main
advantage of torque based control system.

Efficiency
requirements
● Engine startup
● Catalytic heating
● Idle speed control

Efficiency

External torque requests

Torque Torque Injection time
● Cruise control
requirements conversion
● Vehicle speed limit
coordinator Individual
● Vehicle dynamic control
To realize cylinder fuel
● Drivability
To coordinate the Torque ideal torque cut-off
torque and
Internal torque requests efficiency
● Engine startup Torque requirements
● Idle speed control Ignition timing
● Engine speed limit
● Engine protection

Fig. 2.3 Torque-based TB10 System Structure

Comparing with previous engine EFI 4. Phase sensor and sequential fuel
management system based on engine load, injection help to improve the emissions;
TB10 system mainly features:
5. The system supports high-pressure fuel
1. The new engine functional structure of rail and gasoline direct injection;
variable torque has strong expandability
and is easily compatible with other 6. Support exhaust gas turbocharger
systems; control;

2. New modular software structure and 7. Support VVT variable intake control;
hardware structure ensures high 8. Preset exhaust temperature model and
portability; air-fuel ratio model maximize the system
3. Model based basic characteristic efficiency;
diagrams of the engine are mutually 9. The system integrates theft protection
independent, which will simplify the feature, and supports push-to-start
calibration process; function;

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10. Coordinate various torque requirements (1) Electronic throttle opening

intensively to improve drivability;
(2) Fuel injection timing and duration of high
11. 32-bit central processing unit, 80-MHz pressure injector
clock frequency, 768k cache;
(3) High pressure fuel pump control signal
12. Support higher emission regulations (CN
IV or above), OBDII, electronic throttle, (4) Low pressure fuel pump control signal
cruise control, etc. (5) Carbon canister control valve opening
2.2 TB10 System I/O Signal (6) Ignition coil dwell angle and ignition
Input signals for major ECU sensors in TB10 advance angle
system include: (7) A/C permission signal
1) Pressurized temperature and pressure (8) Stepless fan control signal
signal
(9) Electronic water pump relay
2) Intake air temperature/pressure signal
(10) Boost pressure limit magnetic valve
3) Electronic throttle angle signal
(11) Air circulation valve
4) Engine coolant temperature signal
(12) Fuel pressure regulator valve
5) Radiator outlet coolant temperature
signal (13) OCV electromagnetic valve
6) Engine speed signal (14) B r a k e v a c u u m p u m p r e l a y ( o n l y
applicable to the TID models)
7) Camshaft phase signal
2.3 System Functions
8) High-pressure fuel rail hydraulic signal
2.3.1 Start Control
9) Knock signal
In the starting process, intake-stroke injection
10) Generator feedback signal is used.
11) Accelerator pedal position signal Fuel injection amount varies according to
12) Clutch switch signal (only applicable to the temperature of the engine; a specific
the MT models) “injection timing” is designated as the initial
injection pulse; before the engine reaches a
13) Oxygen sensor signal certain speed, the gas mixture is enriched.

14) A/C pressure signal Once the engine is running, the system
immediately begins to reduce the start
15) Brake booster pressure signal enrichment, and cancels start enrichment
16) Cruise switch signal (only applicable to until the end of the starting condition; when
the TID models) the engine speed exceeds a certain limit
(1200rpm), the injection timing changes to
17) Brake switch signal inject near the compression TDC.

Signals above enter the ECU where they Ignition angle is also constantly adjusted
are processed to produce the required under starting condition. Ignition angle is also
actuator control signals. These signals constantly adjusted under starting condition,
will be amplified in the output drive circuit and changes with the engine temperature,
and transmitted to relevant actuator, as intake air temperature and engine speed.
shown below:

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2.3.2 H e a t e r a n d T h r e e - w a y C a t a l y s t maintain the balance between the generated

Heating Control torque and “power consumption” of the
engine. During idling, certain amount of
After the engine starts at a low temperature, power must be generated to meet the load
the cylinder charge, fuel injection and requirements. During idling, certain amount
electronic ignition are all adjusted to of power must be generated to meet the load
compensate for higher torque requirements; requirements, including engine crankshaft,
such process will be lasted until the valve gear and accessories, e.g. the internal
temperature rises up to an appropriate friction of the water pump.
threshold.
On the basis of the closed-loop idle speed
In this stage, the most important is to heat control, the torque-based control strategy
the three-way catalyst rapidly, as it may for TB10 system determines the engine
greatly reduce the exhaust emission after it output torque which is necessary to maintain
starts working. In this condition, the ignition the required idle speed in any operating
advance angle is moderately delayed to“heat conditions. This output torque increases/
three-way catalyst” with exhaust gas. decreases with the decrease/increase of
2.3.3 A c c e l e r a t i o n / D e c e l e r a t i o n a n d engine speed. System responds to new
R e v e r s e - To w i n g F u e l C u t - o f f “interference factor” by requiring greater
Control torque, such as turn on/off of the air-
conditioning compressor or enable power
Acceleration/deceleration: in the steering. When the engine temperature is
implementation of the acceleration and much lower, the increase of torque is also
deceleration, adjust the fuel injection quantity required to compensate larger internal
and injection timing in real time based on the friction loss and/or maintain a higher idle
torque model, and implement controls such speed. The sum of all these output torque
as acceleration enrichment, deceleration requirements will be transferred to the torque
dilution, and deceleration fuel cut-off to coordinator which deals with and computes
ensure sensitive power response. the requirements and obtains the relevant
charging density, mixture ingredient and
If the deceleration fuel cut-off occurs during ignition timing.
towing or reverse towing, it refers to the
conditions where the power provided for the 2.3.5 λ closed-loop Control
flywheel by the engine is negative. In this
case, engine friction and pumping loss can be Exhaust aftertreatment is an effective way
used to reduce the vehicle speed. In such a to reduce the concentration of harmful
state, the fuel may be cut off so as to reduce substances in the waste gas. The three-way
the fuel consumption and exhaust emission, catalytic converter can effectively reduce
what’s more, to protect the three-way hydrocarbon (HC), carbon monoxide (CO)
catalyst. and nitrogen oxides (NOx) by 98% or more
where they are converted into water (H2O),
Once the engine speed is reduced to a carbon dioxide (CO2) and nitrogen (N2).
specific one over the idle speed, fuel supply Such high efficiency can only be achieved
may be restored by the fuel injection system. when the engine is operated within a narrow
Meanwhile, the torque-based control system range around the excess air factor λ=1. The
will get the engine torque increased slowly goal of λ closed-loop control is to ensure the
and smoothly (smooth transition). mixture density is within this range.
2.3.4 Idle Speed Control λ closed-loop control system can work only
when the oxygen sensor is equipped, which
Engine running idle will not provide torque for monitors the oxygen content in the waste
the flywheel. To ensure stable operation of the gas at the side of three-way catalyst. Lean
engine at the lowest possible idle speed, the mixture (λ>1) produces about 100mV sensor
closed loop idle speed control system must voltage while the rich mixture (λ<1) produces

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about 800mV sensor voltage. In case of λ=1, current torque demand.

an abrupt change appears in the sensor
voltage. closed-loop control responds to the 2.3.9 Supercharging Air Circulation
input signal (λ>1 indicating too lean mixture Control
and λ<1 indicating too rich mixture) to modify When the supercharging pressure rises
the control variable and produces a modifying sharply caused by the significant engine
factor which serves as the multiplier to modify condition change or other factors, TB10
the fuel injection duration. system controls the electromagnetic valve
2.3.6 Evaporative Emission Control of the air circulation, so as to conduct the air
before and after supercharged and maintain
For the reason of external radiant heat and the pressure balance.
oil return heat transfer, the fuel in the fuel
tank is heated and becomes a fuel vapor The control can effectively avoid the air noise
which contains a lot of HC ingredients and and impeller damage, and prevent high back
thus cannot be directly discharged into the pressure in the pressure cavity, or else it may
atmosphere according to the Evaporative cause reverse towing of the brake or device
Emission Standards. In the system, the fuel damage.
vapor travels through a duct, then enters the 2.3.10 Variable Intake Valve Timing Control
carbon canister and at last is cleaned and
blown into the engine for combustion when The system is based on the torque model,
appropriate. Vapor flow is controlled by ECU. controls OCV electromagnetic valve in
accordance with current engine speed and
2.3.7 High Pressure Fuel Pump Control load, so that the current intake air phase
As for high pressure fuel pressure closed- matches with the optimal intake air phase
loop control, TB10 system adjusts the fuel map; meanwhile, the intake air phase control
pressure regulating valve according to and the camshaft signal form a closed-loop
default MAP, correct the closed loop through control to ensure that the system control is in
high-pressure fuel rail hydraulic pressure progress.
sensor, so that the current hydraulic pressure The intake phase variable system can
matches the engine load. effectively balance the fuel efficiency and
The high pressure fuel pump is a mechanical output performance of the engine, thereby
pump, which is driven by camshaft and maximizing the car performance.
controls the fuel quantity entering into the 2.3.11 Turbocharger Cooling System
high pressure fuel pump through the fuel Control
pressure regulator valve, in order to achieve
stable fuel pressure in the high-pressure fuel The turbocharger works in a hot environment
rail; pressure limiting valve is integrated in for a long time, and too much heat is
the high pressure fuel pump; when the fuel accumulated; after the engine stopped
pressure exceeds the default value (200bar), working, the mechanical water pump stops
the pressure is relieved, and the fuel is working, and the turbocharger should be
returned to low pressure fuel rail. cooled down to ensure effective protection.
2.3.8 Boost Pressure Limit Control The system features shut-off delay of the
electronic water pump, that is, the electronic
TB10 system is based on a torque model, water pump continues running for a period of
controls the pulse width of the supercharging time (8min) after the engine stopped working,
pressure limiting valve in accordance with in order to dissipate heat and protect the
current engine speed and load requirement, turbocharger.
and adjusts the amount of exhaust gas
flowing through the turbine, thereby effectively 2.4 Introduction to System Malfunction
controlling the supercharging pressure of Diagnosis
the intake air, and making it match with the

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Onboard diagnostic system (OBD system) is OBD technology, which will help you have a
a diagnostic system integrated in the engine better understanding of the follow-up content.
control system, and is capable of monitoring
the faulty parts that affect the exhaust 2.4.1 Malfunction Information Records
emission and the status of main engine The engine ECU constantly monitors the
functions. It has the function to identify, store sensors, the actuators, the relevant circuits,
and display fault information through self- the malfunction indicators, the battery voltage
diagnosis malfunction indicator light (MIL). as well as the engine ECU itself and also
To ensure the durability of the emission detects the reliability of the sensor output
control performance in the process of using signals, the actuator drive signals and the
the car, the state explicitly requires in “Light internal signals (such as λ closed-loop
Vehicle Pollutant Emissions Limits and control,
Methods of Measurement (CN IV stage)” coolant temperature, idle speed control and
that all cars must be equipped with the battery voltage control). In case certain faulty
onboard diagnostic (OBD) system, which can part or unreliable signal value is detected, a
identify the deterioration or malfunction of the malfunction information record will be made
parts throughout the life of the car. ¡± immediately by ECU, stored on the RAM
In the service of cars with OBD system, the memory in the form of DTC and displayed in
service personnel can find the faulty parts order of appearance.
quickly and accurately through the diagnostic The faults can be divided into “steady
tester, greatly improving the efficiency and fault” and “occasional fault” according to
quality of service. the frequency (for example, due to the short-
OBD technology involves a lot of brand new term wiring harness breaking or poor contact
concepts. Below is some basic knowledge of of connectors).

Function diagnosis
Function diagnosis ECU

Data acquisition Control command

Sensor Actuator

Engine

Fig. 2.4 Schematic Diagram of Troubleshooting EFI System

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2.4.2 MIL Description and the Control Turn the ignition switch to the ON state, and
Strategy SVS lamp is lit constantly. After started, if the
fault in the memory requires that SVS lamp is
Malfunction indicator light (MIL): the indication lit in failure mode, SVS lamp will be lit in the
required by the regulation for the failure of subsequent driving cycle; if the fault in the
emission-related components or system; MI memory does not require SVS lamp to be lit
is generally an indicator that can be displayed in failure mode, SVS lamp turns off after the
on the instrument panel and the shape engine speed is found.
conforms to the requirements of regulations.
2.4.3 Four Malfunction Types
MIL activation has the following principles:
Type A: signal exceeds the upper limit of
1. Turn on the ignition switch (do not start), normal range.
and MIL is lit continuously.
Type B: signal exceeds the lower limit of
2. In three seconds after the engine is normal range.
started, if the memory doesn’t have the
request to light up the MIL, the MIL will Type C: no signal.
be off.
Type D: has a signal, but the signal is
3. If the memory has the request to light up unreasonable.
the MIL, or ECU has external request to
light up the MIL, MIL will be lit. 2.4.4 Troubleshooting Steps

4. When the ECU has external MIL flashing For vehicles with OBD function, the service
request, or the cause of misfire has MIL generally follows the steps below:
flashing request, or the memory has MIL 1. Connect the diagnostic tester to the
flashing request, MIL will flash at 1Hz diagnostic interface, and turn on the
frequency. diagnostic tester.
SVS light: this is the MIL set by the car
manufacturer for the purpose of vehicle
services; EOBD regulations do not have
clear definition on the shape and activation
principle.

SVS lamp control strategy is based on the

definition of the car manufacturer. Turn the
ignition key to the ON state, and SVS lamp
has the following working conditions in
different modes:

(1) In normal mode, and the fault memory is

free
2. Turn on the “ignition switch” or push to
Turn the ignition switch to the ON state, the start.
ECU immediately initializes, SVS lamp is lit
for four seconds starting from the initialization
and then turns off. If start within 4 seconds,
SVS turns off immediately when the engine
speed is found.

(2) In normal mode, and the fault memory

has fault

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3. Read the fault information (DTC, frozen 2.4.5 Connect the Diagnostic Tester
frame, etc.); refer to the service manual
to confirm the faulty part and type; The system uses “CAN” line communication
develop the service method according protocol and ISO 9141-2 standard diagnostic
to the fault-related information and connector, as shown in Fig. 2.5. This standard
experience. diagnostic connector is fixedly connected on
the engine wiring harness. For the standard
diagnostic connector, 4#, 6#, 14# and
16# pin are used to diagnose the engine
management system (EMS). Pin 4 of the
standard diagnostic connector is connected
to the ground wire of the car; pin 6 and 14 are
connected to pin 101 and 109 of ECU, i.e.“CAN”
line of engine data; pin 16 is connected to
positive terminal of the battery.

4. Eliminate the fault.

Fig. 2.5 ISO9141-2 Standard Diagnostic

Connector

Communication between the engine ECU

and the external diagnostic tester can be
established with the cable “CAN” and the
following operations can be performed:

( S e e “ B Y D E D 4 0 0 D i a g n o s t i c Te s t e r
Introduction” for the details of function and
operation)
5. Clear the memory; properly run
(1) Engine parameter display
the vehicle under the conditions
of troubleshooting; read the fault 1. Rotational speed, coolant temperature,
information, and confirm that the fault throttle position, ignition advance angle,
has been eliminated. injection pulse width, intake air pressure,
intake air temperature, speed, system

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voltage, fuel injection correction, erosion Use 60-2 tooth signal plate to identify speed
rate of the canister, oxygen sensor signal (speed sensor);
waveform;
Electronic throttle control;
2. Target speed, intake air flow, fuel
consumption; Achieve idle torque closed-loop control;

3 Signal voltage of the electronic throttle Feature catalytic converter heating and
position sensor, signal voltage of the protection;
coolant temperature sensor, signal Integrate limp home function;
voltage of the intake temperature sensor,
and signal voltage of the intake pressure Supercharged protection function;
sensor.
Turbocharger cooling delay off function.
(2) EFI system status display

State of the theft protection system, security,

programming, cooling system, steady working
condition, dynamic working condition,
emission control, oxygen sensor, malfunction
indicator, emergency working condition, air-
conditioning system, automatic transmission /
torque request.

(3) Actuator test function

M a l f u n c t i o n i n d i c a t o r, f u e l p u m p , a i r
conditioning relay, fan, ignition, fuel injection
(single-cylinder oil cut-off)

(4) Odometer display

Running mileage, running time

(5) Version information display

Chassis frame number (VIN), ECU hardware

number, ECU software number

(6) Malfunction display

Intake air pressure sensor, intake air

t e m p e r a t u r e s e n s o r, e n g i n e c o o l a n t
temperature sensor, electronic throttle position
sensor, oxygen sensor, oxygen sensor
heating circuit, injector of each cylinder, fuel
pump, speed sensor, phase sensor, carbon
canister control valve, speed signal, idle
speed, system voltage, malfunction indicator.
2.5 System Features

Multi-point sequential direct injection system;

Engine functional structure of variable torque;

Use cylinder detection signal (phase sensor);

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3. TB10 System Component Structure, Principle and Troubleshooting

3.1 Intake Air Pressure/Temperature Sensor

TB10 system uses two intake air pressure/temperature sensors, which are intake air main pipe
pressure/temperature sensor and intake air manifold pressure/temperature sensor.
1) Sensor schematic drawings and electrical schematic diagrams:

Fig. 3-1 Intake Air Pressure/Temperature Sensor Diagram

Theft protection input

Fig. 3-2 Electrical Schematic Diagram of Intake Air Fig. 3-3 Electrical Schematic Diagram of Intake Air
Main Pipe Pressure/Temperature Sensor Manifold Pressure/Temperature Sensor

2) Pin definition:

1- ground;
2- output temperature signal;
3- connected to 5V;
4- output pressure signal

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3.1.1 Installation Position

Temperature
sensor
The intake air main pipe pressure/
temperature sensor is mounted in the intake Pressure cap

pipe in the rear side of the supercharger and Terminal O-ring

in front of the electronic throttle.

The intake air manifold pressure/temperature

sensor is mounted in the intake pipe in the
rear of the intercooler.
3.1.2 Principle Housing with EMI capacitor
connector
The intake air pressure/temperature sensor
consists of the absolute pressure sensor Fig. 3-4 Intake Air Pressure/Temperature
element and temperature sensor element. Sensor Section
The absolute pressure sensor element
consists of one silicon chip. A pressure 3.1.3 Technical Characteristics Parameters
diaphragm is etched in the silicon chip. (1) Limit data
The pressure diaphragm has four piezo
resistors, which form a Wheatstone bridge as Numerical
Parameters Unit
a strain element. In addition to this pressure value
diaphragm, the silicon chip also integrates Power voltage 16 V
signal processing circuit. The silicon chip
and a metal housing form a closed space, in Pressure 500 kPa
which the absolute pressure of the air within
Operating
the reference space is close to zero. Thus a temperature
-40/+130 ºC
microelectronic mechanical system is formed.
The active surface of the silicon chip is (2) Pressure sensor characteristic data
subject to a pressure near zero, and the back
is subject to the intake air absolute pressure
Numerical value
introduced through a pipe. The thickness of Parameters Unit
the silicon chip is only a few micrometers (μm), Minimum Typical Maximum
so that the change of intake air absolute
Range of
pressure will cause mechanical deformation
pressure 10 250 kPa
of the silicon chip, four piezo resistors deform, test
and the resistance value also changes. After Operating
processed by the signal processing circuit -40 130 ºC
temperature
of the silicon chip, the voltage signal which Power
4.75 5.0 5.25 V
has a linear relationship with the pressure voltage
is formed. Intake air temperature sensor Current at
12.5 mA
element is a negative temperature coefficient US = 5.0V
(NTC) resistor, which changes with the intake
(3) Limit data of temperature sensor
air temperature; this sensor feeds a voltage
that represents the intake air temperature Storage temperature: -40/+130ºC
changes to the controller.
(4) Characteristic data of temperature sensor

Operating temperature: -40/+130ºC

Rated resistance at 20° C: 2.5 kΩ±5%

(5) Temperature sensor characteristic curves

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the diameter of the screw head.

Resistance (Ω)

• The maximum installation tightening

force for fixing screws is 4.5kN.
3.1.5 Malfunction and Identification

• Malfunction: flameout, poor idling.

• General reasons: 1. Unusual high

voltage or reverse current in the process
Temperature T (°C)
of using; 2. Vacuum components are
damaged in the process of service.
Fig. 3-5 Temperature Sensor Characteristic
Curve R=f (T) • Service notice: in the process of service,
it is prohibited to impact the vacuum
3.1.4 Installation Considerations components with high-pressure gas;
if any malfunction is discovered and
• The sensor must be installed in the
the sensor should be replaced, check
plane of the intake air pipe of the
whether the generator output voltage
automobile engine. Pressure pipe and
and current are normal.
the temperature sensor extend into the
intake pipe together, and is isolated with • Simple measuring method:
the atmosphere by O-ring.
—— Te m p e r a t u r e s e n s o r : ( r e m o v e t h e
• Install properly (for example, extract connector) switch the digital multimeter
pressure from the intake manifold, and to Ohm, connect the two meters to 1#
incline the pressure pipe), in order to pin and 2# pin sensor respectively, the
ensure that condensed water won’t be rated resistance at 20 ° C is 2.5kΩ±5%,
accumulated in the pressure-sensitive and other relevant resistance values can
element. be measured with above characteristic
curve. Simulation method can also be
• The drilling and fixing of the intake
used for measurements, that is, supply
manifold must be designed in
air to the sensor with a hair dryer (do not
accordance with the supplier drawings,
get too close), and observe the change
to ensure long-term leak-proof and
in the sensor resistance, which should
erosion resistance of the interface base.
be decreased.
• Backpressure may lead to measurement
——Pressure sensor: (attach the connector)
e r r o r, a n d t h e r e f o r e t h e s e n s o r
switch the digital multimeter to DC
shouldn’t be installed directly behind
voltage, connect the black tip to the
the throttle.
ground and connect the red tip to 3# pin
• In addition to the impact of part and 4# pin respectively. In idling state,
joints, the reliable contact of electrical #3 pin should have a reference voltage
connection also depends on the material of 5V, 4# pin is about 1.3V (specific value
quality and dimensional accuracy of the depends on model); in no-load state,
connector. Therefore, it is necessary to slowly open the throttle, the voltage of
use the plugs conforming to the product #4 pin doesn’t change significantly;
technical specifications provided by the quickly open the throttle, the voltage of
manufacturer. #4 pin can reach 4V instantaneously
(specific value depends on model) and
• The maximum diameter of the fixing then decrease to about 1.5V (specific
screw in the hole: 6mm. value depends on model).
• Use the gasket with the minimum
diameter of 10mm or a diameter equal to

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3.2 Coolant Temperature Sensor

In TB10 system, the engine outlet and radiator outlet are installed with a coolant temperature
sensor respectively, and the two sensors the same model.
1) Sensor schematic drawings and electrical schematic diagrams

Fig. 3-6 Coolant Temperature Sensor Diagram

Fig. 3-7 Electrical Diagram of Engine Coolant Fig. 3-8 Electrical Diagram of Radiator Outlet
Temperature Sensor Coolant Temperature Sensor

2) Pin definition:

1- 5V power supply

2- Ground

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3.2.1 Installation Position

Engine coolant temperature sensor is

installed in the engine coolant outlet, and the Bottom
surface
radiator outlet coolant temperature sensor is
installed in the radiator outlet.
3.2.2 Principle
Level line

The coolant temperature sensor is a negative

temperature coefficient (NTC) thermistor,
the resistance of which decreases with the
rise in coolant temperature, but not a linear
Fig. 3-10 Liquid Level Position Diagram
relationship.
(2) Insert the sensor into the mounting
3.3.3 Sensor Characteristic Curve
hole and fix with dedicated snap. The
maximum allowable torque of the plastic
and copper shells of the sensor is 2N.m;
therefore, do not twist the plastic parts of
the sensor forcibly while installing.

(3) In the circuit with 5V voltage as the

power supply, both sides of the sensor
should be connected with a pull-
up resistor (R ≥ 1 kΩ) to avoid self-
heating of the thermistor affecting the
measurement results. If there is no pull-
up resistor or the resistance is too low,
Fig. 3-9 Coolant Temperature Sensor it will cause measurement errors, and
Characteristic Curve even damage the sensor.

3.2.4 Specifications 3.2.6 Malfunction and Identification

1. Power: allowable power on both ends is • Malfunction: difficult to start

0.075W (25° C).
• General reason: man-made.
2. Operating temperature: -40~+130° C
• Simple measuring method: (remove the
3.2.5 Installation Considerations connector) switch the digital multimeter
to Ohm, connect the two meters to 1#
(1) The sensor should be installed in the pin and 2# pin of the sensor respectively,
position that the flow rate of the cooling the rated resistance at 25 ° C is 1.825-
water is higher and can correctly reflect 2.155kΩ, and other values can be
the water temperature, and ensure that measured with above characteristic
the liquid level exceeds the bottom curve. Simulation method can also be
surface shown in Fig. 3-10 at least used for measurements, that is, put
10mm, so that the sensor detects the the working area of the sensor into
accurate cooling water temperature in a boiling water (soak for sufficient time),
shorter time. and observe the change in the sensor
resistance, which should decrease to
300Ω-400Ω (specific values depending
on water temperature).

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3.3 Oxygen Sensor

The upstream oxygen sensor and the downstream oxygen sensor used by the system are the
same model.
1) Sensor diagram

Fig. 3-11 Oxygen Sensor Diagram

2) Electrical diagram

Main relay Main relay

Fig. 3-12 Upstream Oxygen Sensor Electrical Fig. 3-13 Downstream Oxygen Sensor Electrical
Diagram Diagram

3) Pin definition:

1- heating power
2- ECU heating signal
3- oxygen sensor grounding
4- oxygen sensor signal

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3.3.1 Installation Position If the concentration of the mixed gas is low,

the difference in the concentration of oxygen
The upstream oxygen sensor is installed in ion inside and outside the ceramic tube will
the front of the exhaust pipe catalyst. be low, the potential difference is low, only
The downstream oxygen sensor is installed in small amount of oxygen ions move from the
the rear side of the exhaust pipe catalyst. inside to the outside, and the output voltage is
low (close to 100mV); The signal voltage has
3.3.2 Principle sudden change at the theoretical equivalent
air-fuel ratio (λ = 1), as shown in the figure
The oxygen sensor LSF used in this system below.
is flat type oxygen sensor, which is developed
from LSH. LSF stacks the functional
layers (inner and outer electrodes, heating
elements, etc.) in screen printing technology
and forms a sheet. The core element of the

Sensor voltage
oxygen sensor is ZrO2 electrolyte, which
causes oxygen ionization at high temperature
and generates oxygen ions. The structure
is shown in Fig. 3-14. One side of the
ceramic tube connects to the exhaust from
the manifold, and the other side connects
to the atmosphere. Since both sides have Λ<1: mixed gas concentration is high (oxygen
significantly different oxygen concentration, is insufficient)
potential difference is generated between
the inside and outside of the tube wall when Λ>1: mixed gas concentration is low (oxygen
ionization occurs, i.e., the signal voltage. is excessive)

Fig. 3-15 Oxygen Sensor Characteristic

Curves at 600° C
3.3.3 Communication with ECU

Parameters Conditions Min. Max. Unit

Operating
Input voltage 0 1 V
voltage
1. Cable, 2. Protective cover, 3. Plane Reference
Open circuit 420 480 mV
sensing element, 4. Cable voltage

5. Sensor block, 6. Seal ring, 7. Double layer

protective pipe

Fig. 3-14 Oxygen Sensor Structure

If the concentration of the mixed gas is high,

the difference in the concentration of oxygen
ion inside and outside the ceramic tube will
be high, the potential difference is high, a
large amount of oxygen ions move from the
inside to the outside, and the output voltage
is high (close to 800mV-1000mV);

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3.3.4 Technical Characteristics Parameters

(1) Electric data of sensor

Characteristic Measurement Value Unit

At room temperature, for new
sensors, including rated heater cold
Rated resistance 9 Ω
resistance value of the cables and
connectors
Rated voltage 12 V

Heater power supply Uninterrupted working voltage 12~14 V

Maximum supply voltage of the
16.5 V
system

(2) Conditions of use

Value
Measurement Unit
Minimum Maximum

Storage temperature -40 100 ºC

Exhaust temperature 150 (recommended) 930 ºC

Hexagon head for housing 570 ºC

Operating
temperature
Cable and protective cover 250

Connector plug 120 ºC

Permissible fuel additive Unleaded gasoline or low lead gasoline

Engine oil consumption and combustion Standard: ≤ 0.7L/1000km

(3) Service life of leaded gasoline sensor

Lead content in gasoline (g/L) Service life (km)

≤ 0.6 20000

≤ 0.4 30000

≤ 0.15 60000

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3.3.5 Installation Considerations • Recommended material for exhaust

pipe thread: high temperature resistant
(1) Selection criteria of installation point stainless steel, such as: X 5 CrNi 18 9
On the premise that the working temperature DIN 17,440 1.4301 or 1.4303 SAE30304,
of the sensor is ensured, the selection of or SAE 30305 (U.S. standard). Please
sensor installation point should follow the note that the sensor thread must be
principles below: completely covered.

• As close as possible to the engine • The sensor protection tube should

be inserted into the exhaust, but the
• Incline the exhaust pipe as much as connection curling part of the protection
possible, so that the condensed water tube shouldn’t face to the hot exhaust
won’t be accumulated in the upstream directly. Make sure that the sensor
of the installation point, and the exhaust protection tube can not contact with
pipe in front of the installation point the opposite side of the exhaust pipe,
shouldn’t have dimple, bump or sharp especially when it is installed in the
edge. connection of the exhaust manifold
and the twin-tube, materials with
• Do not select the installation point below the minimum deformation to high
the exhaust pipe, which is the first to be temperature should be selected.
wetted.
• The tightening torque for the oxygen
• Independent guide tube is generally sensor is 40~50Nm. Use specified
considered installation lubricant: BOSCH material
• to be the ideal point of installation; in N o . 5 9 6 4 0 8 0 11 2 ( 1 2 0 g / c a n ) o r
case of doubt, carry out contrast test for 5964080145 (450g/can). Using other
pipeline heating rising characteristic to lubricants will cause oxygen sensor
confirm this fact. poisoning.

• For the installation points that can not • For mass production, the exhaust pipe
meet the requirements, the system system should be designed to meet the
application engineer shall conduct more geometric accuracy and airtightness
tests on ceramic thermal shock and requirements.
select appropriate protection measures. • Disassembly required tool: M22 wrench.
(2) Recommended installation program and After disassembly, the surface of the
requirements installation position should be cleaned to
ensure that there is no oil spill.
• The oxygen sensor should be mounted
3.3.6 Malfunction and Identification
with the horizontal angle greater than
or equal to 10 ° (electronic connectors • Malfunction: poor idling, poor
upwards), which can prevent the acceleration, excessive exhaust, fuel
accumulation of condensate water consumption is too high, etc.
between the sensor housing and the
sensor ceramic, as shown in Fig. 3-16. • General reason: 1. moisture enters the
sensor, temperature changes suddenly,
and the probe fractures; 2. Oxygen
sensor “poisoned” (Pb, S, Br, Si)

• Failure judgment:

(1) Check by diagnostic tester

Engine MIL is lit, indicating that the

Fig. 3-16 Oxygen Sensor Mounting engine system has malfunction, and

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diagnostic tester should be used for Fig. 3-17 Diagram of Crankshaft Position
diagnosis; Sensor and Seal Ring

Communicate with the EFI system ECU 2) Sensor and signal wheel
through the diagnostic tester specified
by the car manufacturer, read the Flange oil seal -
malfunction data in ECU, and thus judge encoder assembly

the failure of the oxygen sensor.

Seal ring

(2) Simple electrical performance inspection Crankshaft position

sensor

methods:

- (Remove the plug) turn the digital

multimeter to ohm, connect the two
meters to heat (+) and heat (-) pin of the
sensor respectively, and the resistance
at room temperature is 9Ω. Signal wheel

- (Connect to the connector) in idle state,

switch the digital multimeter to DC
voltage when the oxygen sensor reaches
its working temperature of 350ºC, Fig. 3-18 Crankshaft Position Sensor, Seal
connect two meters to grounding signal Ring and Signal Wheel
and positive signal pin of the sensor
respectively, and the voltage should 3) Electrical diagram
fluctuate between 0.1 and 0.9V quickly
at this time.

- Press the oxygen sensor close to your

ear and shake gently; if there is any
abnormal sound, the internal ceramic
probe may be ruptured.
3.4 Crankshaft Position Sensor

The crankshaft position sensor is integrated

with the seal ring, as shown in Fig. 3-17. The
assembly relationship among the crankshaft
position sensor, seal ring and signal wheel is
shown in Fig. 3-18.
1) Sensor and seal ring diagrams
Fig. 3-19 Crankshaft Position Sensor
Electrical Diagram
Seal ring

4) Pin definition:

1- Power
2- Signal
3- Ground

Crankshaft position sensor

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3.4.1 Installation Position signal, ECU can identify the top dead center
of each cylinder, calculate the crank angle,
On the plane of the signal wheel of the and obtain the engine speed.
crankshaft back cover
3.4.3 External Circuit Diagram of Sensor
3.4.2 Principle

The crankshaft position sensor is a Hall-effect

sensor. The signal wheel is mounted on the
crankshaft, and rotates with a crankshaft. The
signal wheel has totally 60 teeth, of which two
are missing teeth. When each tooth on the
signal wheel passes through the Hall sensor,
the internal magnetic field of the Hall sensor
changes, and the output signal voltage
changes accordingly. According to the pulse
signal of each tooth and the tooth missing
signal, ECU can identify the top dead center
of each cylinder, calculate the crank angle,
and obtain the engine speed. Fig. 3-20 External Electrical Diagram of
3.4.3 External Circuit Diagram of Sensor Crankshaft Position Sensor
3.4.4 Electrical Parameters of Sensor

Parameter Minimum Typical Maximum Unit

Supply
4.2 5 17 V
voltage
Output
voltage 4.2 5 V
(high)
Rotation
30 8000 rpm
speed

3.4.5 Sensor Limit Temperature

100h limit temperature: 160℃

Fig. 3-20 External Electrical Diagram of
Crankshaft Position Sensor Temperature range: -40~150℃

3.4.1 Installation Position Pulse signal

On the plane of the signal wheel of the Crankshaft angle (°)

crankshaft back cover

3.4.2 Principle Fig. 3-21 Crankshaft Tooth Position Pulse
The crankshaft position sensor is a Hall-effect Signal Diagram
sensor. The signal wheel is mounted on the 3.4.6 Malfunction and Identification
crankshaft, and rotates with a crankshaft. The
signal wheel has totally 60 teeth, of which two • Malfunction: engine can’t be started
are missing teeth. When each tooth on the
signal wheel passes through the Hall sensor, • General reason: man-made.
the internal magnetic field of the Hall sensor Simple measuring method: (Connect the
changes, and the output signal voltage connector) turn on the ignition switch but
changes accordingly. According to the pulse do not start the engine; switch the digital
signal of each tooth and the tooth missing

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multimeter to DC voltage, and connect the 3.5.1 Installation Position Camshaft

two meters to 3# and 1# pin of the sensor
respectively; ensure that the reference 3.5.2 Principle
voltage is 5V. Start the engine, and check The phase sensor is a Hall-effect sensor. The
whether the 2# pin signal is normal with the signal wheel is mounted on the camshaft, and
car oscilloscope rotates with a camshaft. The signal wheel has
3.5 Phase Sensor four teeth, of which two are small teeth and
the other two are big teeth, as shown in Fig.
1) Sensor diagram 3-24. When each tooth on the signal wheel
passes through the Hall sensor, the internal
magnetic field of the Hall sensor changes,
and the output signal voltage changes
accordingly.

The phase sensor signal is combined with the

crankshaft position sensor signal to obtain the
position of 1st cylinder compression top dead
center. In addition, the phase sensor signal
is also used for the feedback regulation of
variable valve timing (VVT), which makes the
intake phase control more accurate.

Fig. 3-22 Phase Sensor Diagram

Fig. 3-24 Phase Sensor Signal Wheel

Fig. 3-23 Phase Sensor Electrical Diagram

2) Pin definition:

3) Sensor electrical diagram

1- Power
2- Signal
3- Ground

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3.5.3 Sensor Circuit Diagram and Electrical Parameters

Sensor

Parameter Mark State Minimum Typical Maximum Unit

Supply voltage Vcc 4.5 5 12 V

Supply Current Icc OFF 3 15 mA

Output voltage Vout ON 0.5 V

3.5.4 Signal Diagram

Tooth 1 Tooth 4 Tooth 3 Tooth 2

Tooth space Tooth space Tooth space Tooth space

Tooth 4

Phase sensor
Direction of rotation

Tooth 1
Tooth 3
Tooth 2

In the figure, OP (Operating Point) refers to the falling edge of the electrical signal; RP (Release
Point) refers to the rising edge of the electrical signal.

Fig. 3-25 Signal Diagram

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3.5.5 Malfunction and Identification

• Malfunction: excessive emissions,

increased fuel consumption, can’t
adjust VVT normally, etc.

• General reason: man-made.

• Simple measuring method:

(Connect the connector) turn on the ignition

switch but do not start the engine; switch the
digital multimeter to DC voltage, and connect
the two meters to 3# and 1# pin of the sensor
respectively; ensure that the reference
voltage is 5V. Start the engine, and check Fig. 3-27 Knock Sensor Electrical Diagram
whether the 2# pin signal is normal with the
car oscilloscop. 3) Pin definition
3.6 Knock Sensor

1) Sensor diagram

Kuock sen sor teminal A

Kuock sen sor teminal B

3.6.1 Installation Position

On the body between second and third

cylinder of the engine.
3.6.2 Principle

The working principle of the knock sensor is

Fig. 3-26 Knock Sensor Diagram to encapsulate a piezoelectric ceramic (Fig.
3-28) which has piezoelectric effect, and
2) Sensor electrical diagram the engine enters closed-loop knock control
when the engine load, speed and water
temperature exceed the threshold values
respectively and the knock sensor doesn’t
have malfunction records. When engine
knock occurs, the sensor generates output
voltage with higher amplitude and frequency
than the voltage when there is no knock, and
output to ECU after appropriate filtering and
amplification.

ECU integrates knock signal. When the

integral value within a certain crank angle

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exceeds the threshold, the ECU determines • The machining of the mounting plane and
that the engine is in a knock condition, and the mounting hole must ensure a certain
the ignition advance angle at this moment degree of flatness, perpendicularity and
is reduced by a specific angle; if the knock surface finish, in order to ensure that the
appears again in next cycle, the ignition output signal of the sensor complies with
advance angle is reduced by another specific the requirements.
angle, until the engine won’t have knock
any longer, and then gradually restore ignition • The mounting point should prevent the
advance angle to normal. sensor from prolonged exposure to
liquids such as gasoline, antifreeze, oil,
and brake fluid.
Spring washer
Cable
• Mounting screw dimensions: M8
Vibration mass
• Tightening torque: 20 ± 5 Nm.
Piezoelectric
ceramic • The mounting position of knock
Housing sensor should first meet the following
Pressure sleeve
requirements:

Fig. 3-28 Knock Sensor Structure Diagram • The knock sensor should be installed
at the bottom of the cylinder head
3.6.3 Technical Characteristics Parameters gasket (about 2/3 stroke), close to the
combustion chamber. In fewer case, the
1) Characteristic curve knock sensor also can be installed in
a lower position of the engine cylinder
wall, close to the engine suspension,
to ensure that the vibration of the
combustion chamber is preferably
transmitted to the knock sensor.
Sensitivity

• Considering the temperature resistance

of the wiring harness, knock sensor
should be installed on the cold side of
the engine (the intake side for cross
flowing engines, and the free side for
U-shaped flowing engines).

Frequency • In order to ensure that the distance

from the knock sensor to each cylinder
is same, the knock sensor should be
Fig. 3-29 Characteristic Cure installed symmetrically.
2) Limit data 3.6.5 Malfunction and Identification

Value • Acceleration is poor when the engine is

Parameter Unit running.
Minimum Typical Maximum
• When the engine is running, the engine
Operating MIL is lit, indicating that the engine
-40 +130 ºC
temperature
system has a fault.
3.6.4 Installation Considerations • Eliminate the short circuit or line break
• The mounting points on the engine problem of the wiring harness system.
should comply with the provisions on the • Simple judging method: disconnect
temperature range and vibration levels.

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the wiring harness, switch the digital 3) Pin definition

multimeter to Ohm, connect the two
meters to pin 1# and pin 2# of the
sensor, and the resistance at room
temperature should be greater than 1-Ground
1MΩ. Switch the digital multimeter to
millivolts, tap in the vicinity of the sensor 2-Signal
with a hammer, and the sensor should 3-Power
have voltage signal output at this time.
3.7 High Pressure Fuel Pressure Sensor

1) Sensor diagram 3.7.1 Installation Position

Fuel rail
3.7.2 Principle

The high-pressure fuel pressure sensor has

a steel diaphragm inside, on which the strain
measuring element forms a Wheatstone
bridge. When the fuel rail has hydraulic
pressure, the diaphragm is deformed. The
deformation amount is measured by the
Wheatstone bridge, and the measured
deformation signal is proportional fuel
pressure. The signals are processed by an
integrated signal processing circuit to output
Fig. 3-30 High Pressure Fuel Pressure fuel pressure signal to the ECU.
Sensor Diagram
3.7.3 Characteristic Parameters

(1) Operating characteristics

Value
Parameter Mark Unit
Minimum Typical Maximum

14
Oil pressure
pn 0 20 MPa
range
26
Temperature
T -40 130 ºC
range
Supply
Us 4.75 5.00 5.25 V
voltage

(2) Sensor storage condition

Storage temperature: -30~+60ºC;

Storage humidity: 0~80% RH;

Fig. 3-31 High Pressure Fuel Pressure Maximum storage time of new sensor: 5
Sensor Electrical Diagram years

2) Sensor electrical diagram

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(3) Characteristic curve as the fuel pressure measurement port;

1) 5V characteristic curve • Only use the hex head on the sensor

to tighten the fuel pressure sensor; the
The output voltage value Uout of 5V installation tools (such as pipe pliers)
characteristic curve is shown in Fig. 3-32: should be applied on the hexagonal
Output voltage of 5V characteristic curve Uout
head only;

Upper limit of signal range check (SRC) • The gap between the hexagon head of
the fuel pressure sensor and fuel rail has
the following requirements:

Thread Minimum gap*, unit: mm Interface

M10×1 1.05 Cone

Lower limit of signal range check (SRC)

*The distance between the bottom surface of
Oil pressure p the hex head and top surface of the fuel rail

• It is necessary to ensure that no

Fig. 3-32 Output Voltage of Fuel Pressure
pollutants enter into or remain in the fuel
Function (5V Characteristic Curve)
pressure measurement port during the
2) 3.3V characteristic curve installation process;

The output voltage value Uout of 3.3V Prevent the bolts from contamination of
characteristic curve is shown in Fig. 3-33: liquids or other substances in the process of
installation and transportation.
Output voltage of 3.3V characteristic curve Uout
Upper limit of signal range check (SRC) 3.8 Accelerator Pedal Position Sensor
Signal

1) Sensor diagram

Lower limit of signal range check (SRC)

Oil pressure p

Fig. 3-33 Output Voltage of Fuel Pressure

Function (3.3V Characteristic Curve)
3.7.4 Installation Considerations

• Maximum permissible tightening torque:

35 N.m; Fig. 3-34 Accelerator Pedal Position Sensor
• Follow the instructions on the provided Diagram
accessories drawing to install, and
ensure that no water is gathered on the
diaphragm;

• While installing, the direction of rotation

of the sensor housing must be the same

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the position of the accelerator pedal and

send the signal to ECU. The accelerator
pedal position sensor is a non-contact
dual potentiometer sensor, of which the
circuit diagram is shown in Fig. 3-36. The
ECU supplies 5V voltage. Since the two
potentiometers are installed on the same
phase, when the position of the electronic
accelerator pedal changes, its resistance
value also increases or decreases linearly.
Accelerator pedal Accelerator pedal The two accelerator pedal position sensors
position sensor 2 position sensor 1 send two voltage signals that reflect the
position of the accelerator pedal to the
ECU. The voltage signal of the sensor 1 is
Fig. 3-35 Accelerator Pedal Position Sensor two times of the voltage signal of sensor 2.
Electrical Diagram ECU calculates the torque demand desired
2) Sensor electrical diagram by the driver according to this signal, and
controls the electronic throttle after internal
3) Pin definition coordination.

ECU manages idle speed, acceleration,

deceleration, and injection interruption after
receiving signal from the accelerator pedal
position sensor.

Sensor 1

1) Accelerator pedal position sensor 2

signal

2) Accelerator pedal position sensor 2

power Sensor 2

3) Accelerator pedal position sensor 1

power Fig. 3-36 Accelerator Pedal Position Sensor
Potentiometer Circuit Diagram
4) Accelerator pedal position sensor 1
signal 3.8.3 Characteristic Parameters

5) Accelerator pedal position sensor 1 Supply voltage: UBi=5V±10%; i=1, 2

ground
Supply current: IBi ≤ 10mA; i=1, 2
6) Accelerator pedal position sensor 2
ground Signal current: ISi, max ≤ 50μA; i=1, 2

3.8.1 Installation Position Short circuit protection: U=16V; t=60min

Mounted on the bearing block of the

accelerator pedal
3.8.2 Principle

The accelerator pedal position sensor detects

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Rated resistance: accelerator pedal position sensor wire

connector and ECU wire connector, i.e.
Sensor 1 Sensor 2 1 and 97, 2 and 87, 3 and 8, 4 and 72, 5
and 48, 6 and 27, all of which should be
Sensor
Rp1=1200Ω±40% Rp2=1700Ω±40% no greater than 1.5Ω (connected), and
resistance
Contact
the resistance between wires should be
resistance 1000Ω±400Ω ≤ RSi+RUi ≤ 5000Ω ∞ Ω (disconnected).
and step
down (t>5ms under working condition)
resistance

Sensor signal limit:

Sensor 1 Sensor 2
Minimum
voltage UAi/ 16.5 8.25
UBi*100/[%]
Maximum
voltage UAi/ <87.5 <43.75
UBi*100/[%]

Sensor electrical signal characteristic curve:

3.8.4 Malfunction and Identification

1. Malfunction: hard to start, unstable idle,

poor acceleration.

2. Service method:

1) Turn on the ignition switch, step on the

accelerator pedal slowly to the bottom,
do not unplug the wire connector,
measure the voltage between pin 3
and pin 4 of the sensor, as well as the
voltage between pin 5 and pin 6, both of
which should gradually increase, and the
voltage of sensor 1 should be one time
higher than sensor 2; if not, the sensor
has malfunction and should be replaced.

2) Check the power supply. Unplug the wire

connector from the accelerator pedal
position sensor, turn on the ignition
switch, measure the voltages between
pin 2 and pin 3, pin 2 and ground, pin 1
and pin 5, pin 1 and ground of the wire
connector, all of which should be greater
than 4.5V, or else the circuit or ECU has
malfunction.

3) Check the wiring harness. Turn off

the ignition switch, unplug the wire
connector from the ECU, the measure
the resistance between the pins of the

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3.9 Electronic Control Unit

Electrical schematic diagram and outline drawing of ECU

• ECU electrical schematic diagram

Main relay CAN line

Operating voltage Fuel injection 1

Front oxygen sensor signal Fuel injection 2

Rear oxygen sensor signal Fuel injection 3

Engine coolant temperature Fuel injection 4

Intake manifold
Ignition 1
pressure/temperature

Intake main pipe Ignition 2

pressure/temperature

Throttle position sensor 1 Ignition 4

Throttle position sensor 2 Ignition 4

Knock sensor
Electronic throttle control 1
High pressure fuel
pressure sensor
Electronic throttle control 2
Accelerator pedal

ECU
position sensor 1

Accelerator pedal Electronic cooling water pump

position sensor 2

Brake booster pressure

Fuel pressure regulating valve
sensor

Coolant temperature A/C control

sensor at radiator outlet
Fuel pump relay
Supercharging pressure
sensor
Carbon canister regulating valve
Generator feedback signal
Front oxygen sensor heating
Cruise switch
Rear oxygen sensor heating
Atmospheric pressure sensor
Supercharging pressure limit
electromagnetic valve
Vehicle speed signal input
OCV electromagnetic valve
A/C permission signal
Turbocharger bypass valve
Crankshaft position sensor
Low pressure fuel pump
Camshaft phase sensor
Coolant circulating pump relay
Theft protection input

Fig. 3-38 ECU Electrical Schematic Diagram

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• Outline drawing

Fig. 3-39 ECU Outline Drawing

3.9.1 Installation Position 6) Supercharging control

Engine compartment 7) Intake cam phase control

3.9.2 Principle 8) Supercharging pressure protects and

controls carbon canister control valve
(1) Functions and engine MIL
1) Multi-point sequential direct injection 9) Fuel rationing correction
2) Control ignition 10) Engine speed signal output
3) Idle speed control 11) Vehicle speed signal input
4) Provide sensor power supply: 5V/100mA 12) Malfunction self-diagnosis
5) λ closed-loop control, adaptive 13) Accept engine load signal

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(2) ECU pin definitions:

Pin Connection point Type Pin Connection point Type

1 Fuel pressure regulator valve Output 62 Upstream oxygen sensor heating signal Input

2 Power grounding 1 Ground 63 Engine speed sensor Input

3 Unsustained power supply 1 Input 64 Vehicle speed signal input Input

4 Electronic throttle motor control - Output 65 Theft protection input Input

Intake main pipe pressure/temperature
5 Electronic throttle motor control + Output 66 Ground
sensor grounding
6 67

7 68 Coolant temperature sensor grounding Ground

Accelerator pedal position sensor Radiator outlet coolant temperature
8 Input 69 Ground
signal 1 signal grounding
High pressure fuel pressure sensor
9 Intake air pipe pressure sensor signal Input 70 Ground
grounding
Throttle position sensor signal
10 71 Ground
grounding
Accelerator pedal position sensor signal
11 Intake manifold temperature sensor Input 72 Ground
1 grounding
Radiator outlet coolant temperature
12 Input 73
sensor
13 Upstream oxygen sensor Input 74 Coolant circulating pump relay Output
Downstream oxygen sensor heating
14 Throttle position sensor 1 Input 75 Input
signal
15 76 Engine speed output Output

16 77

17 78 Carbon canister valve Output

18 Brake switch 2 Input 79 Stepless fan control Output

Electronic load 2 (rear windshield
19 Input 80
heating switch)
20 81 OCV electromagnetic valve Output

21 Supercharger air circulating valve Output 82

Boost pressure limit electromagnetic
22 Output 83
valve
23 84

24 85

25 86 Crankshaft sensor power supply Input

Accelerator pedal position sensor 1
26 87 Input
power supply
Accelerator pedal position sensor Electronic throttle sensor power supply
27 Input 88 Input
signal 2 +5V

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Intake manifold pressure/temperature

28 Intake manifold pressure sensor Input 89 Input
sensor
29 High pressure fuel pressure sensor Input 90

30 91

31 Engine coolant temperature sensor Input 92

Intake main pipe air temperature
32 Input 93
sensor
Intake main pipe pressure/temperature
33 Downstream oxygen sensor Input 94 Input
sensor power supply
34 95 Sensor power supply 1 Input

35 Input 96 Sensor power supply 2 Input

Accelerator pedal position sensor 2
36 Brake switch 1 Input 97 Input
power supply
37 Power steering switch Input 98 Ignition signal 3 Input

38 Engine feedback signal Input 99 Ignition signal 1 Input

39 100 Power grounding 2

Output/
40 101 CAN bus interface CAN-L
input
41 Vehicle speed output Output 102 Main relay Output

42 103 Power grounding 3 Ground

43 Fuel pump relay Output 104 Power grounding 4 Ground

44 Camshaft phase sensor Input 105 LIN wire

45 Knock sensor side B Input 106 Ignition signal 4 Input

46 Knock sensor side A Input 107 Ignition signal 2 Input

47 Crankshaft sensor grounding Ground 108 Power grounding 5 Ground

Accelerator pedal position sensor Output/
48 Ground 109 CAN bus interface CAN-H
signal 2 grounding input
49 110

50 111

51 Electronic grounding 1 Ground 112 Ignition switch Input

52 Throttle position sensor 2 Input 113 Continuous power supply Input

53 Intake manifold pressure sensor signal Ground 114 Fuel injector 4 (4# cylinder) Output

54 A/C request signal Input 115 Injector high side 1 Output

55 Upstream oxygen sensor grounding Ground 116 Injector high side 2 Output

56 Downstream oxygen sensor grounding Ground 117 Fuel injector 1 (1# cylinder) Output

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57 Camshaft phase sensor grounding Ground 118 Fuel injector 3 (3# cylinder) Output

58 Electronic grounding 2 Ground 119 Unsustained power supply 2 Input

59 Electronic throttle motor control + Input 120 Unsustained power supply 3 Input

60 Electronic throttle motor control - Input 121 Fuel injector 2 (2# cylinder) Output

61 A/C permission signal Input

Note: Space is defined as NC.

3.9.3 Technical Characteristics Parameters

Limit data

Value
Parameter Unit
Minimum Typical Maximum

Battery voltage 9.0 12 16.0 V

Operating temperature -40 +105 ºC

Storage temperature -40 +65 ºC

Product mass 700 g

3.9.4 Installation Considerations 2. Before removing ECU, remove the

battery terminal and wait at least 5
• Note the ESD protection during minutes;
installation
3. Keep the removed ECU properly;
• Pay attention to the protection of plug
pins 4. Do not install any line to the ECU cable.
3.9.5 Malfunction and Identification • Simple measuring method:

• Malfunction: unstable idle, poor 1. (Connect to the connector) read the

acceleration, can not start, idle speed engine malfunction record with engine
too high, excessive exhaust, difficult to data CAN line;
start, A/C failure, fuel injector control
failure, flame out. 2. (Remove the connector) check whether
ECU cable is intact, especially whether
• General reason: ECU power supply and grounding line
are normal;
1. ECU internal parts are burned and lead
to failure due to electrical overload of 3. Check whether the external sensor
external devices; works normally, whether the output
signal is credible, and whether the line is
2. Circuit board is corroded because water intact;
enters into ECU.
4. Check whether the actuator works
• Service notice: properly, and whether the line is intact;
1. Do not disassemble ECU without 5. Finally, replace ECU and test.
permission in the servicing process;

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3.10 Low Pressure Fuel Pump on the same shaft and sealed in the same
enclosure. Pump and motor in the enclosure
Diagrams and pins are full of gasoline around, which is used for
cooling and lubrication. The battery supplies
power to the electric fuel pump through the
fuel pump relay, which connects the circuit
of the electric fuel pump only when the
engine is started and running. According
to the needs of the engine, the electric fuel
pump may have different flow rates. To
facilitate production, electric fuel pump of the
same structure adjusts the motor speed by
adjusting the coil turns, thereby adjusting the
flow rate. Therefore, the electric fuel pump of
a model can not be used in another model.
Fig. 3-40 Electric Fuel Pump

Pin: the electric fuel pump has two pins

connected to the fuel pump relay. The fuel
pump housing next to the two pins is marked
with “+” and “-”, which represent 1- Oil pump cap
positive and negative respectively.
2- Motor

3- Oil duct

4- Vane machine

Fig. 3-42 Electric Fuel Pump Section

Fuel pump relay Fuel pump

230 battery 201 main relay

Fig. 3-41 Electric Fuel Pump Electrical

3.10.1 Installation Position

In the fuel tank

3.10.2 Principle

The electric fuel pump consists of DC motor,

vane pump and cover (integrated with
check valve, pressure relief valve and anti-
electromagnetic interference components),
as shown below. Pump and motor mounted

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3.10.3 Technical Characteristics Parameters

(1) Limit data

Value
Parameter Unit
Minimum Typical Maximum

Operating voltage 12 V (DC)

System pressure 6 Bar

Ambient temperature
-40 +80 ºC
(for storage and transportation)
Permissible fuel temperature -30 +70 ºC

3.10.4 Installation Considerations manufacturer’s recommended method.

The electric fuel pump should be stored in Do not grip the fuel pump at the fuel pipe or
sealed original packing box. After mounted on inlet strainer.
the car, the maximum allowable storage time
is six months; as accessories, the maximum To prevent fuel pump damage, do not run the
storage time is four years. Over this time, fuel pump in dry state. Do not use a damaged
manufacturers should re-test the performance fuel pump and the fuel pumps that have been
data of the fuel pump. Considering that the dropped to the ground. If the fuel tank falls to
dust in the atmospheric will enter into the oil the ground, replace the fuel pump in the tank.
pump pipeline from the inlet and outlet, the
fuel pumps on storage site must be protected Do not apply pressure onto the fuel inlet
from the effects of the atmosphere. During board. The caulking can not have mechanical
storage, the original packaging must not be stress. The clamping of fuel pump must be
damaged. within the specified range.
The electric fuel pump should be used in the In case of goods return, please send back
fuel tank only. When installing the fuel pump, the fuel pump together with the supply order,
install an inlet strainer with mesh size not inspection sheet and packaging label. The
greater than 60μm or mutually agreed with returned fuel pumps must be packaged in
the client. Do not eject the fuel beam from accordance with the provisions. If the fuel
the vent to inlet strainer, fuel pump holder pump has been used, rinse with the test
or fuel tank walls. Be careful when handling solution and dry in the air. To dry the channel
the fuel pump. First, it is necessary to protect in the fuel pump quickly after the pump
the fuel inlet strainer from load and impact. is soaked in test oil, the high-pressure air
Take out the fuel pump from the plastic source may be used to blow the oil return
packaging carefully. The protective cover is joints of the pump. However, this will damage
removed only when the fuel pump is soon the pressure regulator (also known as
to be installed. Never take out the fuel filter regulating valve), and affect the tightness or
strainer. The foreign matters entering into the firmness, and thus it isn’t allowed to blow
fuel pump inlet or strainer will damage the dry the fuel pump. For safety reasons, we do
fuel pump. not accept pumps that contain fuel.
Keep it clean when install the fuel pipe. The 3.10.5 Malfunction and Identification
inside of the fuel pipe must be clean. Only
use new pipe clip. Make sure that the pipe 1. Malfunction: big noise during running,
clip is in the correct position and follow the poor acceleration, can not start (difficult
to start), etc.

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2. General reasons: poor quality fuel

resulting in: 1. Colloid stacked to form an
insulating layer; 2. Pump bushing and
armature are locked; 3. Fuel level sensor
component is corroded.

3. Service notice:

• According to the needs of the engine,

the electric fuel pump may have

• different flows; the fuel pumps that have

the same shape and can be fitted may
not be appropriate; the part number of
the fuel pump must be consistent with Pressure limiting valve
the original;

• In order to prevent accidental damage of Fig. 3-44 High Pressure Fuel Pump Section
the fuel pump, do not run for a long time
in the dry state; 3.11.1 Installation Position

• If the fuel pump needs to be replaced, Side of the cylinder cover

please clean the fuel tank and piping
3.11.2 Principle
and replace the fuel filter.
The high pressure fuel pump is driven through
4. Simple measuring method:
a 4-point cam on the intake camshaft, and
Connect the fuel pressure gauge to the inlet each lift is 3.5 mm. The latest application also
pipe, start the engine, and observe if the fuel includes that the fuel pump is delivered to the
pump is working. If not working, check if pin high-pressure fuel system in non-injection
“+” has voltage; if working, check if the fuel state.
pressure in idle condition is about 600kpa.
The pressure limiting valve is integrated in the
3.11 High Pressure Fuel Pump high-pressure fuel pump, which can protect
parts from the high pressure of the fuel under
Diagram thermal expansion or malfunction.
3 . 1 1 . 3 Te c h n i c a l C h a r a c t e r i s t i c s
Parameters

Characteristic data

Value
Parameter Unit
Minimum Typical Maximum
System
2 15 MPa
pressure
Fuel supply
pressure 0.65 0.9 MPa
(absolute)
Storage
-40 +70 ºC
temperature
Storage
0 80 %
humidity
Fig. 3-43 High Pressure Fuel Pump Diagram Ambient
-40 +100 ºC
temperature

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Inlet fuel Diagrams and pins

-40 +80 ºC
temperature
Dry running 0 10 Min

Resistance 0.5 Ω
Flow control
valve Insulation
10 MΩ
resistance

3.11.4 Installation Considerations

3.5 Before installing the fuel pump, the

35mm diameter hole in the fuel pump Fig. 3-45 Injector Nozzle
flange must be lubricated with clean,
silicone-free engine oil;

• The sealing area shouldn’t have

parting surface;

• The pump bearing surface must be fully

supported at the flange side;

• All the fallen parts must be scrapped;

• Fuel pump installation provisions:

• The cam is positioned on the bottom

dead center;

• Press the fuel pump to the dead center

(the maximum required force is 1kN);

• Tighten with specified torque; violating Fig. 3-46 Electromagnetic Injector Circuit
installation provisions may cause the Diagram
piston breaking.
Pin:
3.11.5 Malfunction and Identification
Each fuel injector has two pins. The diagram
3.6 Malfunction: poor acceleration, can not is shown in Fig. 3-46
start (difficult to start), jitter in idle state,
etc.

3.7 General reason: caused by poor quality

fuel

1- Service notice:

• Use qualified fuel, and add fuel additives

regularly;

• Refuel before the fuel level indicator is lit,

to reduce the impact of the oil sediments
on the entire engine system;
Fig. 3-47 Fuel Injector on the Fuel Distribution
• Before replacing the fuel pump, please
Pipe
relieve the fuel pressure.
3.12 Injector Nozzle

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3.12.1 Installation Position

Electronic connector

Bushing adapter
At the side near the intake valve
3.12.2 Principle

Drying coil ECU sends electric pulses to the injector

coil to produce magnetic force. When the
magnetic force raises enough to overcome
the resultant force of return spring pressure,
needle valve gravity and frictional force,
the needle valve begins to rise and the fuel
Pinhead injection process begins. When the fuel
Air seal ring injection pulse ends, the pressure of the
Air seal ring One-piece valve
body
return spring makes the needle valve close
again.

Fig. 3-48 Electromagnetic Injector Section

3.12.3 Technical Characteristics Parameters

(1) Limit data

Value
Parameter Unit
Minimum Typical Maximum
Storage temperature (original
-40 +70 ºC
package)
Storage humidity 20 70 %

Fuel injector working temperature -40 +140 ºC

Permissible fuel temperature at
-30 +80 ºC
the fuel injector inlet
Fuel pressure 2 12 MPa

Supply voltage 6 16 V

(2) Allowable fuel even damage.

The fuel injector can only use the fuel in line 3.12.4 Installation Considerations
with the national standard GB 17930-1999
“Unleaded Gasoline for Motor Vehicles” • Do not mix the plug for the fuel injector.
and national environmental protection • For easy installation, it is recommended
standards GWKB 1-1999 “Hazardous to paint silicon-free clean engine oil on
Materials Control Standard for Motor Vehicle the surface of upper O-ring connected to
Gasoline”, and detergent must be added to the fuel distribution pipe. Be careful not
the gasoline. It should be pointed out that the to let the engine oil contaminate inside
gasoline will degenerate if the storage time is and orifice of the fuel injector.
too long. The fuel pump runs for a long time,
and the tank temperature is very high. If the • Load the fuel injector into the seat
gasoline is stored in the fuel tank of such car, vertically, and then fix the fuel injector in
it is easy to be oxidized and deteriorated, the seat with a clip.
which may cause clogging of the injector and

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Notice: 3.12.5 Malfunction and Identification

① The fuel injector clips may be axial or • Malfunction: poor idling, poor
radial; do not misuse. acceleration, can not start (difficult to
start), etc.
② To mount the fuel injector of axial
positioning, ensure that the bayonet • General reason: due to lack of
in the center of the clip is completely maintenance, colloid is accumulated in
clamped into the slot of the fuel the fuel injector and result in failure.
injector, and the slots on both sides
of the clip are completely clamped • Service notice: (refer to Installation
into the outer edge of the fuel injector Considerations)
seat. It is recommended to clean the fuel injector
③ To m o u n t t h e f u e l i n j e c t o r w i t h regularly with dedicated cleaning and
both axial and radial positioning analytical instruments.
requirements, use the radial
positioning clip, and make the
positioning block of the fuel injector
and the positioning pins of the
fuel injector seat locate in the
corresponding slot in the positioning
clip respectively.

④ If the fuel injector has two slots, be

careful to clamp properly; refer to the
original installation location.

• The fuel injector should be installed by

hands; do not knock at the fuel injector
with a hammer or other tools.

• O-ring must be replaced when

disassemble and re-install the fuel
injector. Do not damage the sealing
surface of the fuel injector.

• Do not pull out the support washer of

the O-ring from the fuel injector. While
installing, avoid damaging the inlet,
O-ring, support ring, orifice plate and
electrical plug of the fuel injector. Do not
use if there is any damage.

• After installing the fuel injector, test

the tightness of the distribution pipe
assembly. It is qualified if there is no
leakage.

• The failure parts shall be disassembled

by hands. Remove the clip of the fuel
injector first, and then pull out the injector
from the seat. After disassembling,
ensure that the fuel injector seat is clean
and avoid contamination.

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3.13 OCV Electromagnetic Valve

Diagrams and pins

Power

OCV electromagnetic
valve

Fig. 3-49 OCVOCV Electromagnetic Valve Fig. 3-50 Electrical Diagram

3.13.1 Installation Position

On the valve chamber cover, facing to the intake camshaft

3.13.2 Principle

The engine ECU calculates the optimal intake valve timing according to the crankshaft position
sensor, intake pressure signal, throttle position sensor, camshaft position sensor, water
temperature sensor and vehicle speed signal, to control the location of the engine oil control
valve, make VVT controller generate advance, lag or holding operation, thus changing the valve
timing.

Furthermore, the engine ECU detects the actual valve timing according to the signals from the
camshaft position sensor and the crankshaft position sensor, and thus controls the feedback as
far as possible to obtain predetermined valve timing.

3.13.3 Technical parameters

1) Limit data

Value Unit
Parameter
Minimum Typical Maximum

Operating voltage 11 15.5 V

Maximum axial force 200 N

1) Limit data

Parameter Value Unit

Coil resistance (20° C) 8 Ω

Insulation resistance 25 MΩ

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3.13.4 Installation Considerations Diagrams and pins

• The engine running may be abnormal

when the VVT valve has been removed
and repaired. The valve assembly must
be replaced if there is any malfunction.

• When using engine oil with a higher

viscosity (>15W40), the VVT may not
work in a low temperature state. You are
recommended to use the engine oil with
viscosity below 10W30.

• VVT valve body and OCV

electromagnetic valve have high
precision, and non-genuine engine oil
and filter may cause engine VVT system
working abnormally. Fig. 3-51 Electronic Throttle
3.13.5 Malfunction and Identification
Pin Definition
• Failure: 1. Engines shuddering; 2. Timing
1 Throttle position
over-advance; 3. Timing over-lag sensor power
2 Throttle position
• General reason:
sensor signal 2
• If the movement of the electromagnetic 3 Throttle position
sensor ground
valve is blocked by aluminum scrap, the
4 Throttle position
oil pressure can not be controlled and sensor signal 1
the engine oil flows directly into the oil 5 Electronic throttle
chamber of the camshaft, causing the motor control
camshaft being dislocated for long time. 6 Electronic throttle
At this moment, since the ignition lag of motor control
low speed is different from high speed,
the air pressure flows away from the
Fig. 3-52 Pin Definition (the terminal number
subtle slot, leading to insufficient inlet
in this manual shall prevail)
pressure;
3.14.1 Installation Position
• OCV slide valve is stuck in the advance
position; variable valve timing actuator is The electronic throttle valve is installed on the
stuck in the advance position; timing belt intake pipe of the engine
is too loose, or improper valve timing is
caused by timing belt slipping; 3.14.2 Principle

• Engine oil pressure is too low; OCV slide The position throttle butterfly valve is
valve is stuck in the lagging position; controlled by the motor, positioning control
variable valve timing actuator is stuck module in the ECU controls the motor to
in the lagging position; the oil channel rotate. The product is equipped with two
between the engine oil switch and non-contacting position sensors, which can
OCV, or OCV and variable valve timing monitor the position of the butterfly valve in
actuator may be blocked or leak; timing
real time. The system determines the real-
belt is too loose or improper valve timing
time load and dynamic changes of the engine
is caused by timing belt slipping.
according to the output signal value and its
3.14 Electronic Throttle Assembly rate of change. In the case of power failure,
the butterfly valve is maintained in the initial

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position by the joint action of the return spring

and the torque spring. Composition: throttle
valve, gear drive and return structure, DC
motor, and sensor plugs.
3.14.3 Technical parameters

Characteristic parameters

Value
Parameter Unit
Minimum Typical Maximum
Operating
-40 +140 ºC
temperature
Operating
6 16 V
voltage
Fig. 3-53 Supercharger Air Circulating Valve
3.14.4 Installation Considerations

Ch e ck th e ti g h tn e s s o f j u n c ti o n w hen
installing in accordance with the specification.
3.14.5 Malfunction and Identification

• Failure: hard to start, unstable idle, poor

acceleration or “backfire”, exhaust Power
emission abnormal

• General reason: due to lack of

maintenance, the throttle body is dirty
and causes malfunction

• Checking:

• Check accelerator pedal position sensor

signal

• Check the line connection

• Clean the throttle body, and check the

throttle shaft and throttle motor Fig. 3-54 Electrical Diagram
• Check the throttle body for leaks 3.15.1Installation Position
• Check the ignition and working of the In the intake pipe on the compressor’s side
fuel injector. The abnormal working
of engine also will lead to disorder of 3.15.2 Principle
the electronic throttle body control and
cause a malfunction illusion. Since the turbine is driven with the exhaust
power, the throttle is closed, but the turbine
3.15 Supercharger Air Circulating Valve blades (the compressor impeller) still
continue to rotate under the effect of inertia
Diagrams and pins when throttle back in the driving process
(such as shift, a sudden stop). At this time,
since the throttle valve is truncated and the
impeller continues to boost, the air pressure
in the intake manifold (between the throttle

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valve and the turbine) will increase rapidly. In

order to protect the supercharging system,
when the pressure reaches a certain limit, the
intake bypass valve opens, leads the excess
air (pressure) back between the filter and the
turbine to reduce the pressure.
3.15.3 Technical Parameters

Value
Parameter Unit
Minimum Typical Maximum
Fuel
205 °C
temperature Fig. 3-54Supercharging Pressure Limit
Ambient Magnetic Valve
-40 +160 °C
temperature
Operating
8 12 16 V
voltage

3.15.4 Installation Considerations

While installing, check all pipes, which should

be linked firmly, and shouldn’t have leaks or
Power
aging.
3.15.5 Malfunction and Identification

• Failure: the engine makes crisp“giggle”

sound

• General reason: damage of

supercharging air circulating valve

• Simple measurement: use a multimeter

to test the resistance value of the wire
connections, which shall comply with the
technical requirements. If not, replace
the valve. If yes, check the supply
voltage of the wire connections. Fig. 3-55Electrical Diagram
3.16 S u p e r c h a r g i n g P r e s s u r e L i m i t 3.16.1Installation Position
Magnetic Valve
Next to the turbocharger, at the bottom of the
Diagrams and pins intake pipe

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idle state; it is strictly prohibited to step

on the accelerator pedal immediately
after installed;

• Ensure that the intake air is clean, and

replace the air filter regularly;

• Check the level of engine oil regularly, to

avoid bearing failure and rotating parts
stuck due to lack of engine oil;

• Replace the engine oil and oil filter

regularly;

• Regularly check the flexibility of the

regulator lever of the bypass valve.
3.16.5 Malfunction and Identification

1. Failure: no sense of pushing back

in acceleration, fuel consumption
increased, exhaust temperature risen

Fig. 3-56 Electrical Diagram 2. General reason: actuator opening

pressure is too low due to jamming of
3.16.2 Principle the exhaust bypass valve
The supercharging pressure limit magnetic 3. Service method: the preset opening
valve is controlled by the engine controller pressure should be set up and adjusted
rhythmically, which also manipulates the properly, and install the supercharger
control pressure of the pressure sensor of strictly in accordance with the
exhaust gas turbocharger as well as the requirements.
waste gate valve, and part of exhaust gas
is guided into the exhaust device through 3.17 Ignition Coil
the turbine; the turbine power and the
Diagram and circuit diagram
supercharging pressure also can be adjusted
through it.
3.16.3 Technical Parameters

Value
Parameter Unit
Minimum Typical Maximum
Fuel
205 °C
temperature
Ambient
-40 +140 °C Fig. 3-57 Single Spark Ignition Coil
temperature
Operating
8 12 16 V
voltage

3.16.4 Installation Considerations

• Install in strict accordance with the

requirements;

• After installed, run for 5-10 minutes in

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3# coil is connected to the ignition switch;

Engine ground
primary winding pin of 4# coil is connected
PIN 3 to ECU 106# pin; high pressure side: two
secondary winding terminals are connected to
ECU control signal the spark plug of 4# engine cylinder through
PIN2
ignition wire.
3.17.1 Installation Position

Positive electrode of On the engine valve chamber cover

battery High voltage
PIN1 side
3.17.2 Principle

The ignition coil consists of the primary coil,

Fig. 3-58 Single Spark Ignition Coil Circuit secondary coil, core, and housing. When
Diagram the ground channel of a primary winding is
Note: This system has four ignition coils, connected, the primary winding is charged.
and the secondary of each ignition coil is Once the ECU cuts off the circuit of primary
connected to a cylinder respectively; the winding, the charging is suspended, and
ignition sequence is 1-3-4-2. a high voltage is induced in the secondary
winding, resulting in discharging of the spark
Pin definition: plug. Each cylinder is equipped with an
ignition coil, and installed above the spark
1# cylinder ignition coil plug. The separate ignition doesn’t require
Low pressure side: primary winding pin of high voltage wire, so that the ignition energy
1# coil is connected to the ignition switch; loss is further reduced.
primary winding pin of 1# coil is connected 3.17.3 T e c h n i c a l C h a r a c t e r i s t i c s
to ECU 99# pin; high pressure side: two Parameters
secondary winding terminals are connected to
the spark plug of 1# engine cylinder through 1. Characteristic data
ignition wire;
Basic parameters Value Unit
2# cylinder ignition coil
Rated voltage 14 V
Low pressure side: primary winding pin of
2# coil is connected to the ignition switch; Wire resistance 150±50 mΩ
primary winding pin of 2# coil is connected
to ECU 107# pin; high pressure side: two
secondary winding terminals are connected to 2. Limit data
the spark plug of 2# engine cylinder through
ignition wire; Value
Parameter Unit
3# cylinder ignition coil Minimum Typical Maximum

Low pressure side: primary winding pin of Operating

6 16 V
voltage
3# coil is connected to the ignition switch;
Permissible
primary winding pin of 3# coil is connected working -30 +120 °C
to ECU 98# pin; high pressure side: two temperature
secondary winding terminals are connected to
the spark plug of 3# engine cylinder through 3.17.4 Installation Considerations
ignition wire;
1 The ignition coils are installed on the
4# cylinder ignition coil engine. The recommended installation
torque is 8Nm±2Nm to avoid plastic
Low pressure side: primary winding pin of housing collapse caused by excessive

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torque;

2 Sharp metal edge structure shouldn’t

appear around the ignition coil, and at
least 2mm gap should be kept between
the high-voltage output area and the
surrounding metal surface;

3 In the process of installation, the high

voltage extension bar and spark plug
connection should be connected reliably,
or else it will cause high voltage leakage
and misfire.
3.17.5 Malfunction and Identification Coolant circulating Coolant circulating
pump relay pump
4 Malfunction: can’t start
Battery Main relay
5 General reason: the current is too large,
resulting in burning, damage by external
force, etc. Fig. 3-60 Electric Water Pump Electrical
Diagram
6 Service notice: it is prohibited to test the
ignition in “short-circuit method” in 3.18.1 Installation Position
the servicing process, in order to avoid
damage to the electronic controller. On the coolant circulating pipeline of the
engine
3.18 Electric Water Pump
3.18.2 Principle
Diagrams and pins
After the water pump is opened, the impeller
rotate at high speed in the pump (the
pump body must be filled with liquid before
opening), the liquid in the pump rotates with
the impeller and is thrown out from the outlet
by the impeller under the effect of centrifugal
force; the liquid thrown out gradually slows
down in the pump body diffusion chamber, a
vacuum area of low pressure is formed at the
center of the impeller, the liquid in the pool
flows into the pump through the suction pipe
under the effect of the external atmospheric
pressure. The volume of the pump diffusion
chamber is fixed; with the increase of the
liquid being thrown out, the pressure is
gradually increased, and finally is discharged
from the outlet of the pump. The liquid is
Fig. 3-59 Electric Water Pump sucked up continuously from the pool and
then discharged from the pump outlet.
3.18.3 T e c h n i c a l C h a r a c t e r i s t i c s
Parameters

1) Characteristic data

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Basic parameters Value Unit

Rated Power 24 W

Rated voltage 12 V

Operating current 2 A

2) Limit data

Value
Fig. 3-61 Carbon Canister Control Valve
Parameter Unit
Minimum Typical Maximum
Operating
9 16 V
voltage

3.18.4 Installation Considerations Main relay

7 Appearance: the surface of injection
molded parts should be flat and smooth,
doesn’t have obvious injection flaws,
and the metal pieces are not rusted;

8 Al l co mp o n e n ts s h a l l b e i n s t a l l ed
properly; missing or reverse installation
isn’t allowed;

9 Applicable media: automotive antifreeze

and water;

10 There is no impurity in the pump body,

and the inlet and the outlet are protected
with dust cover.
Fig. 3-62 Carbon Canister Control Valve
3.18.5 Malfunction and Identification Circuit Diagram
11 Failure: the water temperature is too Pin:
high or rises too fast
Carbon canister control valve only has two
12 Service: pins, of which one connects to 201# pin of
the main relay output terminal, and the other
a) Check if the pump water pressure can connects to 78# pin of ECU.
meet the requirements;
3.19.1 Installation Position
b) Check if the water pump is leaking;
On the vacuum pipeline of the carbon canister
c) Check if the driving end of the water - intake manifold
pump is securely connected;
3.19.2 Principle
d) Check if the water pump is blocked
The carbon canister in the evaporative
3.19 Carbon Canister Electromagnetic
emission control system absorbs oil vapor
Valve
from the tank until the oil vapor is saturated.
Diagrams and pins The electronic controller controls the carbon
canister electromagnetic valve to open,
the fresh air and the saturated oil vapors

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in the carbon canister form regeneration

Value
air flow, and re-introduce into the engine Parameter Unit
in ta ke ma ni fo l d . Th e v a l v e i n te g r at es Minimum Typical Maximum
electromagnetic coil, and the electronic
Operating
controller changes the duty cycle of the pulse 9 16 V
voltage
signal supplied to the electromagnetic coil
Permissible
according to the different working conditions working -30 +120 ºC
of the engine, thereby changing the degree temperature
of opening of the valve. Furthermore, the Permissible
degree of valve opening is also subject to the storage -40 +130 ºC
influence of the pressure differential across temperature
the valve. Tolerable inlet
and outlet
800 mbar
The activated carbon filter in the carbon pressure
difference
canister collects the oil vapor, and the
Permissible
air flow delivered into the engine intake 108
switching time
manifold is measured by the carbon canister
electromagnetic valve. It is controlled by the (2) Characteristic data
pulses emitted by the electronic controller,
and the opening duration and frequency must
Value
adapt to the engine operating conditions. Parameter Unit
Minimum Typical Maximum

Rated voltage 13.5 V

Resistance at
26 Ω
+20ºC
Current at the
0.5 A
rated voltage

3.19.4 Installation Considerations

1. The connection of carbon canister

electromagnetic valve, the carbon
1. From the fuel tank, 2. Carbon canister, 3. canister and the intake manifold is
Atmosphere, 4. Carbon canister control valve, shown in Fig. 3-63.
5. To the intake manifold, 6. Throttle
2. To avoid transfer of solid sound, it is
∆ P is the difference between environmental recommended to mount the carbon
pressure Pu and intake manifold pressure Ps canister control valve on the hose.
Fig. 3-63 Installation Diagram of Evaporative 3. The air flow direction while installing
Emission Control System and Carbon must meet the requirements.
Canister Control Valve.
4. Appropriate measures such as filtration
3.19.3 T e c h n i c a l C h a r a c t e r i s t i c s and purification are required to prevent
Parameters particulates and other foreign matters
entering into the carbon canister
(1) Limit data
electromagnetic valve from the carbon
canister or hose.

5. It is recommended to install a protective

filter (mesh size < 50μm) in the outlet of
the carbon canister.
3.19.5 Malfunction and Identification

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• Malfunction: function unavailable vacuum pressure is capable of driving the

brake booster according to the voltage signal
• General reason: foreign objects enter from the pressure sensor.
into the valve, resulting in corrosion or
poor sealing. Principle

• Service notice: In order to get the full braking pressure

as quickly as possible, the brake booster
1. The air flow direction while installing needs to have a certain degree of vacuum.
must meet the requirements; In the homogeneous air inflation mode, the
2. If control valve failure is caused by black degree of throttle opening is large, so that the
particles in the valve and the control vacuum inside the intake manifold is small. If
valve should be replaced, check the the brake pedal is stepped on consecutively
condition of the carbon canister; for several times, the vacuum strength
accumulated in the brake booster can not
3. In the service process, avoid water, oil, brake effectively.
or other liquids entering into the valve;
3.20.3 Technical parameters
4. To avoid transfer of solid sound, it is
recommended to mount the carbon Value
canister electromagnetic valve on the Parameter Unit
hose or add a rubber cover. Minimum Typical Maximum

3.20 Brake Vacuum Pump Rated voltage 12 V

Diagram Operating
6 16 V
voltage
Operating
5 8 A
current
Start current >10 A
Operating
-30 90 ºC
temperature
Storage
-40 120 ºC
temperature
Weight 1100 g

3.20.4 Installation Considerations

After replacement, check if the vacuum tube

leaks; start the engine, run for 5 minutes and
check the braking.
3.20.5 Malfunction and Identification
Fig. 3-64 Brake Vacuum Pump • Failure: engine jitter or sporadic unstable
3.20.1 Installation Position idle occurs after stepping on the brake
continuously
This sensor is mounted on the pipe between
the intake manifold and the brake booster. • Service:
It measures the pressure in the pipe or the 1. The vacuum pipe is aged and leaks;
brake booster. replace the vacuum pipe.
3.20.2 Principle
2. Vacuum pump is damaged; replace the
The engine control unit determines if the vacuum pump.

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4. Diagnostic Procedures of Servicing TB10 System as per DTC

Note:

1. The multimeter mentioned below is the digital multimeter; it is prohibited to check the EFI
system line with pointer multimeter.

2. For servicing of vehicles with anti-theft system, if the “Follow-up Steps” column indicates to
replace ECU, please program the ECU after replacement.

3. ECM mentioned in DTC refers to ECU

Diagnosis help:

1. Do not neglect the effect of vehicle maintenance, cylinder pressure, and mechanical ignition
timing on the system during servicing;

If the DTC still exists after checking the wiring harness and sensor as prompted, replace the ECU
and test again.

If the DTC is cleared, the ECU is in trouble; if it still exists, replace with the original ECU and
repeat the steps to service it.

Scanning tool or diagnostic tester mode description:

Below is the meaning, corresponding diagnostic strategies and possible reasons of the DTC in
current TB10 system, as well as the failure processing strategies, which can be used as reference
in the service process.

Each ECU pin mentioned below is subject to the actual wiring harness diagram.

DTC: P0010: open circuit of camshaft regulating valve control circuit

Step 1: Read DTC with the diagnostic tester

Result: P0010: open circuit of camshaft regulating valve control circuit

Prompt:

Following problem might exist

1) OCV electromagnetic valve (camshaft regulating valve) signal circuit is open; use a
multimeter to measure the resistance between the ECU and pin 2# of regulating valve signal
wire.

DTC: P0016: intake phase deviation is large

Step 1: Read DTC with the diagnostic tester

Result: P0016: intake phase deviation is large

Prompt:

Following problems might exist

1. Camshaft regulating valve failure or blockage; check camshaft regulating valve.

2. Camshaft valve timing is not correct; check if the valve timing is correct, and if the timing
chain has “tooth-leap”.

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DTC: P0030: open circuit of front oxygen heating control circuit

Step 1: Read DTC with the diagnostic tester

Result: P0030: open circuit of front oxygen heating control circuit

Prompt:

Following problems might exist

1) The circuit connecting pin 2# of the front oxygen sensor and ECU pin is open; use a
multimeter to measure the resistance between the ECU and pin 2# of the front oxygen
sensor.

2) The circuit connecting pin 1# of the front oxygen sensor and the main relay is open; use a
multimeter to measure the resistance between pin 1# of the front oxygen sensor and the
main relay.

3) The circuit between pin 1# and pin 2# of the oxygen sensor is open; with a multimeter to
measure the resistance between pin 1# and pin 2# of the front oxygen sensor.

DTC: P0031: voltage of front oxygen heating control circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0030: voltage of front oxygen heating control circuit is too low
Prompt:

Following problem might exist

1) The circuit between the front oxygen sensor and ECU pin is short to ground; use a
multimeter to measure the resistance of ECU pin to ground.

DTC: P0032: voltage of front oxygen heating control circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P0032: voltage of front oxygen heating control circuit is too high

Prompt:

Following problems might exist

1) The circuit connecting ECU pin and pin 1# of upstream oxygen sensor is shorted; measure
the resistance between the ECU pin and pin 1# of upstream oxygen sensor.

2) The circuit connecting ECU pin and other circuits of the power supply is shorted; use a
multimeter to measure the voltage of pin 2# of the oxygen sensor connector.

DTC: P0033: open circuit of supercharging bypass valve control circuit

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Step 1: Read DTC with the diagnostic tester

Result: P0033: open circuit of supercharging bypass valve control circuit

Prompt:

Following problem might exist

1) The circuit connecting the bypass valve signal and ECU pin is open; use a multimeter to
measure the resistance between ECU and the bypass valve signal line.

DTC: P0034: voltage of supercharging bypass valve control circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0034: voltage of supercharging bypass valve control circuit is too low

Prompt:

Following problem might exist

1) The bypass valve signal circuit is shorted to ground; use a multimeter to measure the
resistance between the ECU pin and ground.

DTC: P0035: voltage of supercharging bypass valve control circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P0035: voltage of supercharging bypass valve control circuit is too high

Prompt:

Following problem might exist

1) The bypass valve signal circuit is shorted to power supply; use a multimeter to measure the
voltage of ECU pin.

DTC: P0036: open circuit of rear oxygen heating control circuit

Step 1: Read DTC with the diagnostic tester

Result: P0036: open circuit of rear oxygen heating control circuit

Prompt:

Following problems might exist

1) The circuit between ECU pin and pin 2# of rear oxygen sensor is open; measure the
resistance between ECU and pin 2# of the rear oxygen sensor.

2) The circuit connecting pin 1# of the rear oxygen sensor and the main relay is open; measure
the resistance between pin 1# of the rear oxygen sensor and the main relay.

3) The circuit between pin 1# and pin 2# of the rear oxygen sensor is open; measure the
resistance between pin 1# and pin 2# of the rear oxygen sensor.

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DTC: P0037: voltage of rear oxygen heating control circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0037: voltage of rear oxygen heating control circuit is too low
Prompt:

Following problem might exist

1) The circuit between pin 2# of the rear oxygen sensor and ECU pin is shorted to ground; use
a multimeter to measure the resistance of ECU pin to ground.

DTC: P0038: voltage of rear oxygen heating control circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P0038: voltage of rear oxygen heating control circuit is too high
Prompt:

Following problems might exist

1) The circuit between ECU pin and pin 1# of rear oxygen sensor is shorted; use a multimeter
to measure the resistance between ECU pin and pin 1# of the rear oxygen sensor.

2) The circuit between ECU pin and other circuits of the power supply is shorted; use a
multimeter to measure if the voltage of ECU pin is normal.

DTC: P0089: control circuit malfunction of fuel pressure regulating valve

Step 1: Read DTC with the diagnostic tester

Result: P0089: control circuit malfunction of fuel pressure regulating valve

Prompt:

Following problems might exist

1) The circuit connecting regulating valve signal and ECU pin is open; use a multimeter to
measure the resistance between ECU pin and pin 2# of the fuel pressure regulator valve.

2) The circuit connecting the regulating valve signal and ECU is shorted to ground; use a
multimeter to measure the resistance between the ECU pin and ground.

3) The circuit connecting the regulating valve signal and ECU is shorted to power supply; use
a multimeter to measure the voltage of ECU pin.

DTC: P0097: voltage of supercharged air temperature sensor circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0097: voltage of supercharged air temperature sensor circuit is too low

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Prompt:

Following problem might exist

1) The sensor signal connecting to ECU pin is shorted to ground; use a multimeter to measure
the resistance between the sensor signal circuit of ECU pin and the ground.

DTC: P0098: voltage of supercharged air temperature sensor circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P0098: voltage of supercharged air temperature sensor circuit is too high
Prompt:

Following problem might exist

1) The sensor signal connecting to ECU pin is shorted to power supply; use a multimeter to
measure if the voltage of the sensor signal circuit of ECU pin is normal.

DTC: P0107: voltage of intake air pressure sensor circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0107: voltage of intake air pressure sensor circuit is too low
Prompt:

Following problem might exist

1) The sensor signal connecting to ECU pin is shorted to ground; use a multimeter to measure
the resistance between the sensor signal circuit of ECU pin and the ground.

DTC: P0108: voltage of intake air pressure sensor circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P0108: voltage of intake air pressure sensor circuit is too high
Prompt:

Following problem might exist

1) The sensor signal connecting to ECU pin is shorted to power supply; use a multimeter to
measure if the voltage of the sensor signal circuit of ECU pin is normal.

DTC: P0112: voltage of intake air temperature sensor circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0112: voltage of intake air temperature sensor circuit is too low

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Prompt:

Following problem might exist

1) The sensor signal connecting to ECU pin is shorted to ground; use a multimeter to measure
the resistance between the sensor signal circuit of ECU pin and the ground.

DTC: P0113: voltage of intake air temperature sensor circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P0113: voltage of intake air temperature sensor circuit is too high
Prompt:

Following problem might exist

1) The sensor signal connecting to ECU pin is shorted to power supply; use a multimeter to
measure if the voltage of the sensor signal circuit of ECU pin is normal.

DTC: P0117: voltage of coolant temperature sensor circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0117: voltage of coolant temperature sensor circuit is too low

Prompt:

Following problem might exist

1) The sensor signal connecting to ECU pin is shorted to ground; use a multimeter to measure
the resistance between the sensor signal circuit of ECU pin and the ground.

DTC: P0118: voltage of coolant temperature sensor circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P0118: voltage of coolant temperature sensor circuit is too high

Prompt:

Following problem might exist

1) The sensor signal connecting to ECU pin is shorted to power supply; use a multimeter to
measure if the voltage of the sensor signal circuit of ECU pin is normal.

DTC: P0121: throttle position sensor unreasonable

Step 1: Read DTC with the diagnostic tester

Result: P0121: throttle position sensor unreasonable

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Prompt:

Following problem might exist

1) The electronic throttle position sensor malfunctions; replace the throttle assembly.

DTC: P0122: voltage of throttle position sensor line A is too low

Step 1: Read DTC with the diagnostic tester

Result: P0122: voltage of throttle position sensor line A is too low

Prompt:

Following problem might exist

1) The sensor 1 signal circuit connecting to ECU pin is shorted to ground; use a multimeter to
measure the resistance between the sensor 1 signal circuit of ECU pin and the ground.

DTC: P0123: voltage of throttle position sensor line A is too high

Step 1: Read DTC with the diagnostic tester

Result: P0123: voltage of throttle position sensor line A is too high

Prompt:

Following problem might exist

1) The sensor 1 signal connecting to ECU pin is shorted to power supply; use a multimeter to
measure if the voltage of the sensor 1 signal circuit of ECU pin is normal.

DTC: P0131: voltage of front oxygen sensor circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0131: voltage of front oxygen sensor circuit is too low

Prompt:

Following problem might exist

1) The sensor signal connecting to ECU pin is shorted to ground; use a multimeter to measure
the resistance between the sensor signal circuit of ECU pin and the ground.

DTC: P0132: voltage of front oxygen sensor circuit is too high

Failure cause description: after starting the engine, ECU measures the voltage of upstream
oxygen sensor circuit; if the signal voltage is higher than 1.5V for a long period of time, it is
confirmed that the voltage of the front oxygen sensor circuit is too high.

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Step 1: Read DTC with the diagnostic tester

Result: P0132: voltage of front oxygen sensor circuit is too high

Prompt:

Following problems might exist

1) The signal circuit connecting ECU pin and pin 1# of the oxygen sensor is shorted; use a
multimeter to measure the resistance between the signal circuit of ECU pin and pin 1# of
the oxygen sensor connector.

2) The signal circuit connecting ECU pin and other circuits of the power supply are shorted;
measure the voltage of the signal circuit connecting to ECU pin.

DTC: P0134: open circuit of front oxygen sensor circuit

Failure cause description: after starting the engine, ECU measures the voltage of upstream
oxygen sensor circuit; if the signal voltage always changes between 0.4V and 0.6V, it is confirmed
that the front oxygen sensor circuit is open.

Step 1: Read DTC with the diagnostic tester

Result: P0134: open circuit of front oxygen sensor circuit

Prompt:

Following problems might exist

1) The circuit connecting oxygen sensor to ECU pin is open; use a multimeter to measure the
resistance between ECU connector and 4# connector of the oxygen sensor.

2) Oxygen sensor connectors aren’t connected properly; check the connectors.

DTC: P0137: voltage of rear oxygen sensor circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0137: voltage of rear oxygen sensor circuit is too low

Prompt:

Following problem might exist

1) The signal circuit connecting to ECU pin is shorted to ground; use a multimeter to measure
the resistance between the signal circuit of ECU pin and the ground.

DTC: P0138: voltage of rear oxygen sensor circuit is too high

Failure cause description: after starting the engine, ECU measures the voltage of downstream
oxygen sensor circuit; if the signal voltage is higher than 1.5V for a long period of time, it is
confirmed that the voltage of the rear oxygen sensor circuit is too high.

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Step 1: Read DTC with the diagnostic tester

Result: P0138: voltage of rear oxygen sensor circuit is too high

Prompt:

Following problems might exist

1) The signal circuit connecting ECU pin and pin 1# of the oxygen sensor is shorted; use a
multimeter to measure the resistance between the signal circuit of ECU pin and pin 1# of
the oxygen sensor connector.

2) The signal circuit connecting ECU pin and other circuits of the power supply are shorted;
use a multimeter to measure the voltage of the signal circuit connecting to ECU pin.

DTC: P0140: open circuit of rear oxygen sensor circuit

Failure cause description: after starting the engine, ECU measures the voltage of downstream
oxygen sensor circuit; if the signal voltage always changes between 0.4V and 0.6V, it is confirmed
that the downstream oxygen sensor circuit is open.

Step 1: Read DTC with the diagnostic tester

Result: P0140: open circuit of rear oxygen sensor circuit

Prompt:

Following problems might exist

1) The circuit connecting oxygen sensor to ECU pin is open; use a multimeter to measure the
resistance between ECU connector and 4# connector of the oxygen sensor.

2) ECU or oxygen sensor connectors aren’t connected properly; check the connectors.

DTC: P0192: voltage of fuel pressure sensor circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0192: voltage of fuel pressure sensor circuit is too low

Prompt:

Following problem might exist

1) The signal circuit connecting to ECU pin is shorted to ground; use a multimeter to measure
the resistance between the signal circuit of ECU pin and the ground.

DTC: P0193: voltage of fuel pressure sensor circuit is too high

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Step 1: Read DTC with the diagnostic tester

Result: P0193: voltage of fuel pressure sensor circuit is too high

Prompt:

Following problem might exist

1) The sensor signal connecting to ECU pin is shorted to power supply; use a multimeter to
measure the voltage of the signal circuit of ECU pin.

DTC: P0201: open circuit of 1# fuel injector control circuit

DTC: P0202: open circuit of 2# fuel injector control circuit

DTC: P0203: open circuit of 3# fuel injector control circuit

DTC: P0204: open circuit of 4# fuel injector control circuit

Step 1: Read DTC with the diagnostic tester

The results are:

P0201: open circuit of 1# fuel injector control circuit

P0202: open circuit of 2# fuel injector control circuit

P0203: open circuit of 3# fuel injector control circuit

P0204: open circuit of 4# fuel injector control circuit

Prompt:

Following problems might exist

1) The circuit between pin 2# of fuel injector connector and ECU pin is open; use a multimeter
to measure the resistance between ECU connector and pin 2# of the fuel injector connector.

2) ECU or fuel injector connectors aren’t connected properly; check the connectors.

DTC: P0221: throttle position sensor signal unreasonable

Step 1: Read DTC with the diagnostic tester

Result: P0221: throttle position sensor signal unreasonable

Prompt:

Following problem might exist

1) The electronic throttle position sensor malfunctions; replace the throttle assembly.

DTC: P0222: voltage of throttle position sensor line B is too low

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Step 1: Read DTC with the diagnostic tester

Result: P0222: voltage of throttle position sensor line B is too low

Prompt:

Following problem might exist

1) The sensor 2 signal circuit connecting to ECU pin is shorted to ground; use a multimeter to
measure the resistance between the sensor 2 signal circuit of ECU pin and the ground.

DTC: P0223: voltage of throttle position sensor line B is too high

Step 1: Read DTC with the diagnostic tester

Result: P0223: voltage of throttle position sensor line B is too high

Prompt:

Following problem might exist

1) The sensor 2 signal connecting to ECU pin is shorted to power supply; use a multimeter to
measure if the voltage of the sensor 2 signal circuit of ECU pin is normal.

DTC: P0226: pedal position sensor signal unreasonable

Step 1: Read DTC with the diagnostic tester

Result: P0226: pedal position sensor signal unreasonable

Prompt:

Following problem might exist

1) The sensor malfunctions; replace the sensor.

DTC: P0227: voltage of pedal position sensor line 1 is too low

Step 1: Read DTC with the diagnostic tester

Result: P0227: voltage of pedal position sensor line 1 is too low

Prompt:

Following problem might exist

1) The sensor 1 signal circuit connecting to ECU pin is shorted to ground; use a multimeter to
measure the resistance between the sensor 1 signal circuit of ECU pin and the ground.

DTC: P0228: voltage of pedal position sensor line 1 is too high

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Step 1: Read DTC with the diagnostic tester

Result: P0228: voltage of pedal position sensor line 1 is too high

Prompt:

Following problem might exist

1) The sensor 1 signal circuit connecting to ECU pin is shorted to power supply; use a
multimeter to measure the voltage of the signal circuit of ECU pin.

DTC: P0236: supercharging pressure sensor signal unreasonable

Step 1: Read DTC with the diagnostic tester

Result: P0236: supercharging pressure sensor signal unreasonable

Prompt:

Following problem might exist

1) In the supercharging pressure sensor, the sensing element leaks, the pressure sensor is
damaged, the installation location of the pressure sensor leaks, the characteristics of the
pressure sensor shift.

DTC: P0237: voltage of supercharging pressure sensor circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0237: voltage of supercharging pressure sensor circuit is too low

Prompt:

Following problem might exist

1) The sensor signal connecting to ECU pin is shorted to ground; use a multimeter to measure
the resistance between the sensor signal circuit of ECU pin and the ground.

DTC: P0238: voltage of supercharging pressure sensor circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P0238: voltage of supercharging pressure sensor circuit is too high

Prompt:

Following problem might exist

1) The sensor signal connecting to ECU pin is shorted to power supply; use a multimeter to
measure the voltage of the signal circuit of ECU pin.

DTC: P0261: voltage of low side of 1# fuel injector is too low

DTC: P0264: voltage of low side of 2# fuel injector is too low

DTC: P0267: voltage of low side of 3# fuel injector is too low

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DTC: P0270: voltage of low side of 4# fuel injector is too low

Step 1: Read DTC with the diagnostic tester

The results are:

P0261: voltage of low side of 1# fuel injector is too low

P0264: voltage of low side of 2# fuel injector is too low

P0267: voltage of low side of 3# fuel injector is too low

P0270: voltage of low side of 4# fuel injector is too low

Prompt:

Following problem might exist

1) The low side circuit connecting to ECU pin is shorted to ground; use a multimeter to
measure the resistance between the circuit of ECU pin and the ground.

DTC: P0262: voltage of low side of 1# fuel injector is too high

DTC: P0265: voltage of low side of 2# fuel injector is too high

DTC: P0268: voltage of low side of 3# fuel injector is too high

DTC: P0271: voltage of low side of 4# fuel injector is too high

Step 1: Read DTC with the diagnostic tester

The results are:

P0262: voltage of low side of 1# fuel injector is too high

P0265: voltage of low side of 2# fuel injector is too high

P0268: voltage of low side of 3# fuel injector is too high

P0271: voltage of low side of 4# fuel injector is too high

Prompt:

Following problem might exist

1) The low side circuit connecting to ECU pin is shorted to power supply; use a multimeter to
measure the voltage of the circuit of ECU pin.

DTC: P0263: short circuit between low side and high side of 1# fuel injector

DTC: P0266: short circuit between low side and high side of 2# fuel injector

DTC: P0269: short circuit between low side and high side of 3# fuel injector

DTC: P0272: short circuit between low side and high side of 4# fuel injector

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Step 1: Read DTC with the diagnostic tester

The results are:

P0263: short circuit between low side and high side of 1# fuel injector

P0266: short circuit between low side and high side of 2# fuel injector

P0269: short circuit between low side and high side of 3# fuel injector

P0272: short circuit between low side and high side of 4# fuel injector
Prompt:

Following problem might exist

1) The circuit between pin 1# and pin 2# of the fuel injector is shorted; use a multimeter to
measure the resistance between pin 1# and pin 2# of the fuel injector.

DTC: P0300: single-cylinder or multi-cylinder misfire

DTC: P0301: 1# cylinder misfire

DTC: P0302: 2# cylinder misfire

DTC: P0303: 3# cylinder misfire

DTC: P0304: 4# cylinder misfire

Failure cause description: misfire refers that the combustion process within the cylinder is
interrupted or can not burn because the ignition system can not effectively release the ignition
energy (ignition failure), the fuel injection quantity has deviation (in the concentration of the gas
mixture), the cylinder compression pressure is too low, or any other reason; misfire will result in
excessive emissions, or damage the three-way catalyst due to overheating. For OBD diagnostic
test, the system determines that the misfire malfunction occurs if the misfire times exceed a set
value.

Step 1: Read DTC with the diagnostic tester

The results are:

P0300: single cylinder or multi-cylinder misfire

P0301: 1# cylinder misfire

P0302: 2# cylinder misfire

P0303: 3# cylinder misfire

P0304: 4# cylinder misfire

Prompt:

Following problems might exist

1) The fuel injector needs cleaning.

2) The air inlet line needs cleaning.

3) Ignition system failure; check and replace the corresponding spark plug and ignition coil of
the cylinder with misfire, and check if the circuit of ignition coil is open.

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DTC: P0335: crankshaft position sensor signal malfunction

Failure cause description: after the engine is started, ECU monitors the crankshaft position
sensor signal and the phase sensor signal at the same time. If the signals from phase sensor are
received continuously, but signals from crankshaft position sensor can’t be received, the system
determines that the crankshaft sensor line doesn’t have signal.

Step 1: Read DTC with the diagnostic tester

Result: P0335: crankshaft position sensor signal malfunction

Prompt:

Following problems might exist

1) The circuit connecting crankshaft position sensor to the ECU is open; use a multimeter to
measure the resistance between the crankshaft position sensor and the ECU.

2) Open circuit of the crankshaft position sensor; use a multimeter to measure the internal
resistance of the crankshaft position sensor.

3) ECU or sensor connectors aren’t connected properly; check the connectors.

DTC: P0336: crankshaft position sensor signal unreasonable

Step 1: Read DTC with the diagnostic tester

Result: P0336: crankshaft position sensor signal unreasonable

Prompt:

Following problem might exist

1) Crankshaft position sensor is damaged; replace the sensor.

DTC: P0340: camshaft position sensor signal malfunction

Step 1: Read DTC with the diagnostic tester

DTC: P0340: camshaft position sensor signal malfunction

Prompt:

Following problems might exist

1) The circuit connecting camshaft sensor to the ECU is open; use a multimeter to measure
the resistance between the camshaft sensor and the ECU.

2) Open circuit of the camshaft position sensor; use a multimeter to measure the internal
resistance of the camshaft sensor.

3) Connectors aren’t connected properly; check the connectors.

DTC: P0341: camshaft position sensor signal unreasonable malfunction

Failure cause description: camshaft sensor (phase sensor) uses Hall element to sense a trigger
wheel rotating with the camshaft, and thus monitors the position of the camshaft. The phase
signals received by the ECU should change alternately between the high level and low level

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regularly; if the ECU only detects slow change between high level and low level or irregular
change, it is confirmed as camshaft sensor signal malfunction.

Step 1: Read DTC with the diagnostic tester

Result: P0341: camshaft position sensor signal unreasonable

Prompt:

Following problem might exist

1) Camshaft sensor is damaged; replace the sensor.

DTC: P0351: open circuit of 1# ignition coil control circuit

DTC: P0352: open circuit of 2# ignition coil control circuit

DTC: P0353: open circuit of 3# ignition coil control circuit

DTC: P0354: open circuit of 4# ignition coil control circuit

Step 1: Read DTC with the diagnostic tester

The results are:

P0351: open circuit of 1# ignition coil control circuit

P0352: open circuit of 2# ignition coil control circuit

P0353: open circuit of 3# ignition coil control circuit

P0354: open circuit of 4# ignition coil control circuit

Prompt:

Following problems might exist

1) The circuit between pin 2# of ignition coil connector and ECU pin is open; use a multimeter
to measure the resistance between ECU connector and pin 2# of the ignition coil connector.

2) The circuit connecting the ignition coil to the main relay is open; use a multimeter to
measure the resistance between pin 3# of ignition coil connector and the main relay.

3) ECU or ignition coil connectors aren’t connected properly; check the connectors.

DTC: P0444: open circuit of carbon canister electromagnetic valve control circuit

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Step 1: Read DTC with the diagnostic tester

Result: P0444: open circuit of carbon canister electromagnetic valve control circuit
Prompt:

Following problems might exist

1) The circuit between pin 2# of carbon canister electromagnetic valve connector and ECU pin
is open; use a multimeter to measure the resistance between ECU connector and pin 2# of
the carbon canister electromagnetic valve connector.

2) The circuit connecting the carbon canister electromagnetic valve to the main relay is
open; use a multimeter to measure the resistance between pin 1# of carbon canister
electromagnetic valve connector and the main relay.

3) ECU or carbon canister electromagnetic valve connectors aren’t connected properly;

check the connectors.

4) Internal open circuit between pin 1# and pin 2# of the carbon canister electromagnetic
valve; use a multimeter to measure the resistance between pin 1# and pin 2# of the carbon
canister electromagnetic valve.

DTC: P0458: voltage of carbon canister electromagnetic valve control circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0458: voltage of carbon canister electromagnetic valve control circuit is too low
Prompt:

Following problem might exist

1) The circuit between pin 2# of the carbon canister electromagnetic valve connector and ECU
is shorted to ground; use a multimeter to measure the resistance between ECU pin and the
ground.

DTC: P0459: voltage of carbon canister electromagnetic valve control circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P0459: voltage of carbon canister electromagnetic valve control circuit is too high
Prompt:

Following problems might exist

1) The circuit between ECU pin and pin 1# of the carbon canister electromagnetic valve is
shorted; use a multimeter to measure the resistance between ECU pin and pin 1# of the
carbon canister electromagnetic valve.

2) The circuit between ECU pin and other circuits of the power supply is shorted; use a
multimeter to measure if the voltage of ECU pin is normal.

DTC: P0476: open circuit of supercharging pressure limit valve control circuit

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Step 1: Read DTC with the diagnostic tester

Result: P0476: open circuit of supercharging pressure limit valve control circuit
Prompt:

Following problems might exist

1) The circuit between pin 2# of supercharging pressure limit valve connector and ECU pin is
open; use a multimeter to measure the resistance between ECU connector and pin 2# of
the supercharging pressure limit valve connector.

2) The circuit connecting the supercharging pressure limit valve to the main relay is open; use
a multimeter to measure the resistance between pin 1# of the supercharging pressure limit
valve connector and the main relay.

3) ECU or supercharging pressure limit valve connectors aren’t connected properly; check
the connectors.

4) Internal open circuit between pin 1# and pin 2# of the supercharging pressure limit valve;
use a multimeter to measure the resistance between pin 1# and pin 2# of the supercharging
pressure limit valve.

DTC: P0477: voltage of supercharging pressure limit valve control circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P0477: voltage of supercharging pressure limit valve control circuit is too low
Prompt:

Following problem might exist

1) The circuit between pin 2# of the supercharging pressure limit valve and ECU is shorted to
ground; use a multimeter to measure the resistance between ECU pin and the ground.

DTC: P0478: voltage of supercharging pressure limit valve control circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P0478: voltage of supercharging pressure limit valve control circuit is too high
Prompt:

Following problems might exist

1) The circuit between ECU and pin 1# of the supercharging pressure limit valve is
shorted; use a multimeter to measure the resistance between ECU pin and pin 1# of the
supercharging pressure limit valve.

2) The circuit between ECU pin and other circuits of the power supply is shorted; use a
multimeter to measure if the voltage of ECU pin is normal.

DTC: P0480: open circuit of stepless fan control circuit

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Step 1: Read DTC with the diagnostic tester

Result: P0480: open circuit of stepless fan control circuit

Prompt:

Following problems might exist

1) The circuit between stepless fan and ECU pin is open; use a multimeter to measure the
resistance between ECU connector and stepless fan.

2) ECU or supercharging pressure limit valve connectors aren’t connected properly; check
the connectors.

DTC: P0562: system voltage is too low

DTC: P0563: system voltage is too high

Step 1: Read DTC with the diagnostic tester

The results are:

P0562: system voltage is too low

P0563: system voltage is too high

Prompt:

Following problems might exist if the system voltage is too low

1) The generator has been damaged and can not generate electricity or the battery electricity
leaks.

2) Generator excitation circuit is open.

Following problem might exist if the system voltage is too high

1) Generator regulator has been damaged and can’t control the generating capacity, resulting
in high voltage of power generation.

DTC: P0620: AC generator load malfunction

Step 1: Read DTC with the diagnostic tester

Result: P0620: AC generator load malfunction

Prompt:

Following problems might exist

1) The circuit connecting the generator to the ECU line malfunctions (open circuit or low
voltage); check the circuit.

2) The generator malfunctions; replace the generator.

DTC: P0627: open circuit of fuel pump control circuit

DTC: P0628: voltage of fuel pump control circuit is too low

DTC: P0629: voltage of fuel pump control circuit is too high

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Step 1: Read DTC with the diagnostic tester

The results are:

P0627: open circuit of fuel pump control circuit

P0628: voltage of fuel pump control circuit is too low

P0629: voltage of fuel pump control circuit is too high

Prompt:

Following problems might exist if the circuit is open

1) The circuit connecting the fuel pump relay of the ECU and the fuel pump relay is open; use
a multimeter to measure the resistance to the control circuit of the fuel pump relay of the
ECU.

2) The circuit between the relay and the main relay is open; use a multimeter to measure the
resistance between the relay and the main relay.

3) The circuit of the electromagnetic coil of the relay is open; use a multimeter to measure the
internal resistance of the relay.

Following problem might exist if the voltage is too low

1) The circuit connecting the fuel pump relay of the ECU and the fuel pump relay is shorted to
ground; use a multimeter to measure the resistance of the control circuit of the fuel pump
relay of the ECU to ground.

Following problem might exist if the voltage is too high

1) The circuit connecting the fuel pump relay of the ECU and the fuel pump relay is shorted to
power supply; use a multimeter to measure the voltage of the control circuit of the fuel pump
relay of the ECU.

DTC: P0633: ECM and theft protection system authentication fails

Step 1: Read DTC with the diagnostic tester

Result: P0633: ECM and theft protection system authentication fails

Prompt:

Following problems might exist

1) Intelligence key authentication fails; the intelligence key may have internal failure; check the
intelligence key.

2) ECM malfunction; replace the ECM.

DTC: P0645: open circuit of A/C permission control circuit

DTC: P0646: voltage of A/C permission control circuit is too low

DTC: P0647: voltage of A/C permission control circuit is too high

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Step 1: Read DTC with the diagnostic tester

The results are:

P0645: open circuit of A/C permission control circuit

P0646: voltage of A/C permission control circuit is too low

P0647: voltage of A/C permission control circuit is too high

Prompt:

Following problem might exist if the circuit is open

1) The A/C permission control circuit connecting to the ECU is open; use a multimeter to
measure the resistance of A/C permission control circuit connecting to the ECU.

Following problem might exist if the voltage is too low

1) The A/C permission control circuit connecting to the ECU is shorted to ground; use a
multimeter to measure the resistance to ground of A/C permission control circuit connecting
to the ECU.

Following problem might exist if the voltage is too high

1) The A/C permission control circuit connecting to the ECU is shorted to ground; use a
multimeter to measure the voltage of A/C permission control circuit connecting to the ECU.

DTC: P0691: voltage of stepless fan control circuit is too low

DTC: P0692: voltage of stepless fan control circuit is too high

Step 1: Read DTC with the diagnostic tester

The results are:

P0691: voltage of stepless fan control circuit is too low

P0692: voltage of stepless fan control circuit is too high

Prompt:

Following problem might exist if the voltage is too low

1) The stepless fan control circuit connecting to the ECU is shorted to ground; use a multimeter
to measure the resistance to ground of the stepless fan control circuit connecting to the
ECU.

Following problem might exist if the voltage is too high

1) The stepless fan control circuit connecting to the ECU is shorted to power supply; use a
multimeter to measure the voltage of the stepless fan control circuit connecting to the ECU.

DTC: P1601: stepless fan motor stalled or short circuit

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Step 1: Read DTC with the diagnostic tester

Result: P1601: stepless fan motor stalled or short circuit

Prompt:

Following problems might exist

1) Stepless fan is stalled; check if the fan is blocked by foreign objects.

2) The fan motor is stalled; check if the motor is stuck.

3) Internal short circuit of the motor; check the internal resistance of the motor.

DTC: P1602: stepless fan overtemperature protection or electronic errors

Step 1: Read DTC with the diagnostic tester

Result: P1602: stepless fan overtemperature protection or electronic errors

Prompt:

Following problem might exist

1) The fan motor is damaged; replace the motor or fan.

DTC: P1611: ECM internal failure 1

DTC: P1612: ECM internal failure 2

DTC: P1613: ECM internal failure 3

DTC: P1614: ECM internal failure 4

DTC: P1615: ECM internal failure 5

DTC: P1616: ECM internal failure 6

DTC: P1617: ECM internal failure 7

DTC: P1618: ECM internal failure 8

Step 1: Read DTC with the diagnostic tester

The results are:

P1611: ECM internal failure 1

P1612: ECM internal failure 2

P1613: ECM internal failure 3

P1614: ECM internal failure 4

P1615: ECM internal failure 5

P1616: ECM internal failure 6

P1617: ECM internal failure 7

P1618: ECM internal failure 8

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Prompt:

Following problems might exist

1) ECM internal failure; replace the ECM.

DTC: P1621: intercooler system malfunction

Failure cause description: since the intercooler system does not work properly, the temperature of
the intake air through the intercooler is still very high; at this moment, the intake air temperature
of the intake manifold is close to the supercharged intake air temperature, resulting in decreased
engine performance; if the ECU detects that the temperature difference is small, it is confirmed
that the intercooler system malfunctions.

Step 1: Read DTC with the diagnostic tester

Result: P1621: intercooler system malfunction

Prompt:

Following problems might exist

1) The intercooler has foreign matters inside or dirt blocks up the flow of coolant.

2) Thermostat malfunction of the intercooler system causes the coolant in the intercooler can
not circulate normally; check the thermostat.

DTC: P2088: voltage of camshaft regulating valve control circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P2088: voltage of camshaft regulating valve control circuit is too low
Prompt:

Following problem might exist

1) The circuit between the control signal pin of the camshaft regulating valve and ECU is
shorted to ground; use a multimeter to measure the resistance between ECU pin and the
ground.

DTC: P2089: voltage of camshaft regulating valve control circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P2089: voltage of camshaft regulating valve control circuit is too high
Prompt:

Following problems might exist

1) The circuit connecting pin 2# of camshaft regulating valve to the ECU and pin 1# of the
camshaft regulating valve is shorted; use a multimeter to measure the resistance between
ECU pin and pin 1# of the camshaft regulating valve.

2) The circuit connecting pin 2# of camshaft regulating valve to the ECU is shorted to other
circuits of the power supply; use a multimeter to measure if the voltage of pin 2# of camshaft
regulating valve is normal.

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DTC: P2100: open circuit of throttle motor control circuit

Step 1: Read DTC with the diagnostic tester

Result: P2100: open circuit of throttle motor control circuit

Prompt:

Following problems might exist

1) The circuit between the throttle motor and ECU pin is open; use a multimeter to measure
the resistance between ECU connector and throttle motor control circuit.

2) ECU or connectors of the throttle motor control circuit aren’t connected properly; check the
connectors.

DTC: P2102: voltage of throttle motor control circuit is too low

Step 1: Read DTC with the diagnostic tester

Result: P2102: voltage of throttle motor control circuit is too low

Prompt:

Following problem might exist

1) The circuit between the throttle motor and ECU is shorted to ground; use a multimeter to
measure the resistance between ECU pin and the ground.

DTC: P2103: voltage of throttle motor control circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P2103: voltage of throttle motor control circuit is too high

Prompt:

Following problem might exist

1) The throttle motor control circuit is shorted power supply; use a multimeter to measure the
voltage of ECU pin.

DTC: P2118: throttle regulating malfunction or open circuit of control line

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Step 1: Read DTC with the diagnostic tester

Result: P2118: throttle regulating malfunction or open circuit of control line

Prompt:

Following problems might exist

1) The throttle body is damaged and should be replaced.

2) Short circuit between the positive pole and negative pole of the throttle motor control; use
a multimeter to measure the resistance between the positive pole and negative pole of the
throttle motor control.

3) The voltage of the positive pole of the throttle motor control is high; use a multimeter to
measure the voltage between the positive pole and negative pole of the throttle motor
control.

DTC: P2119: mechanical failure of the throttle body

Step 1: Read DTC with the diagnostic tester

Result: P2119: mechanical failure of the throttle body

Prompt:

Following problem might exist

1) The throttle body is damaged and should be replaced.

DTC: P2121: pedal position sensor signal unreasonable

Step 1: Read DTC with the diagnostic tester

Result: P2121: pedal position sensor signal unreasonable

Prompt:

Following problem might exist

1) Pedal position sensor is damaged and should be replaced.

DTC: P02122: voltage of pedal position sensor line 2 is too low

Step 1: Read DTC with the diagnostic tester

Result: P2122: voltage of pedal position sensor line 2 is too low

Prompt:

Following problem might exist

1) The circuit between pedal position sensor 2 signal and ECU is shorted to ground; use a
multimeter to measure the resistance of ECU pin to ground.

DTC: P02123: voltage of pedal position sensor line 2 is too high

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Step 1: Read DTC with the diagnostic tester

Result: P2123: voltage of pedal position sensor line 2 is too high

Prompt:

Following problem might exist

1) The circuit between pedal position sensor 2 signal circuit is shorted to power supply; use a
multimeter to measure the voltage of ECU pin.

DTC: P2147: voltage of high side of 1# fuel injector is too low

DTC: P2150: voltage of high side of 2# fuel injector is too low

Step 1: Read DTC with the diagnostic tester

The results are:

P2147: voltage of high side of 1# fuel injector is too low

P2150: voltage of high side of 2# fuel injector is too low

Prompt:

Following problem might exist

1) The high side circuit connecting to ECU pin is shorted to ground; use a multimeter to
measure the resistance between the circuit of ECU pin and the ground.

DTC: P2148: voltage of high side of 1# fuel injector is too high

DTC: P2151: voltage of high side of 2# fuel injector is too high

Step 1: Read DTC with the diagnostic tester

The results are:

P2148: voltage of high side of 1# fuel injector is too high

P2151: voltage of high side of 2# fuel injector is too high

Prompt:

Following problem might exist

1) The high side circuit connecting to ECU pin is shorted to power supply; use a multimeter to
measure the voltage of the circuit connecting to ECU pin.

DTC: P2184: voltage of cooling water temperature sensor circuit at the radiator outlet is too low

Step 1: Read DTC with the diagnostic tester

Result: P2184: voltage of cooling water temperature sensor circuit at the radiator outlet is too low
Prompt:

Following problem might exist

1) The circuit between cooling water temperature sensor circuit at the radiator outlet and ECU
is shorted to ground; use a multimeter to measure the resistance of ECU pin to ground.

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DTC: P2185: voltage of cooling water temperature sensor circuit at the radiator outlet is too high

Step 1: Read DTC with the diagnostic tester

Result: P2123: voltage of pedal position sensor line 2 is too high

Prompt:

Following problem might exist

1) The circuit between cooling water temperature sensor circuit at the radiator outlet and ECU
is shorted to power supply; use a multimeter to measure the voltage of ECU pin.

DTC: P2227: atmospheric pressure sensor signal unreasonable

Step 1: Read DTC with the diagnostic tester

Result: P2227: atmospheric pressure sensor signal unreasonable

Prompt:

Following problem might exist

1) The atmospheric pressure sensor integrated in ECU malfunctions; replace the ECU.

DTC: P2228: voltage of atmospheric pressure sensor circuit is too low

DTC: P2229: voltage of atmospheric pressure sensor circuit is too high

Step 1: Read DTC with the diagnostic tester

The results are:

P2228: voltage of atmospheric pressure sensor circuit is too low

P2229: voltage of atmospheric pressure sensor circuit is too high

Prompt:

Following problem might exist

1) The atmospheric pressure sensor integrated in ECU malfunctions; replace the ECU.

DTC: P2300: voltage of 1# ignition coil control circuit is too low

DTC: P2303: voltage of 2# ignition coil control circuit is too low

DTC: P2306: voltage of 3# ignition coil control circuit is too low

DTC: P2309: voltage of 4# ignition coil control circuit is too low

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Step 1: Read DTC with the diagnostic tester

The results are:

P2300: voltage of 1# ignition coil control circuit is too low

P2303: voltage of 2# ignition coil control circuit is too low

P2306: voltage of 3# ignition coil control circuit is too low

P2309: voltage of 4# ignition coil control circuit is too low

Prompt:

Following problem might exist

1) The circuit connecting to ECU pin is shorted to ground; use a multimeter to measure the
resistance to ground of ECU pin.

DTC: P2301: voltage of 1# ignition coil control circuit is too high

DTC: P2304: voltage of 2# ignition coil control circuit is too high

DTC: P2307: voltage of 3# ignition coil control circuit is too high

DTC: P2310: voltage of 4# ignition coil control circuit is too high

Step 1: Read DTC with the diagnostic tester

The results are:

P2301: voltage of 1# ignition coil control circuit is too high

P2304: voltage of 2# ignition coil control circuit is too high

P2307: voltage of 3# ignition coil control circuit is too high

P2310: voltage of 4# ignition coil control circuit is too high

Prompt:

Following problem might exist

1) The circuit connecting to ECU pin is shorted to power supply; use a multimeter to measure
the voltage of ECU pin.

DTC: P2600: open circuit of cooling pump control circuit

Step 1: Read DTC with the diagnostic tester

Result: P2600: open circuit of cooling pump control circuit

Prompt:

Following problem might exist

1) The cooling pump signal circuit connecting to ECU is open; use a multimeter to measure the
resistance between ECU pin and cooling pump signal wire.

DTC: P2602: voltage of cooling pump control circuit is too low

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Step 1: Read DTC with the diagnostic tester

Result: P2602: voltage of cooling pump control circuit is too low

Prompt:

Following problem might exist

1) The circuit of cooling pump signal connecting to ECU is shorted to ground; use a multimeter
to measure the resistance to ground of ECU pin.

DTC: P2603: voltage of cooling pump control circuit is too high

Step 1: Read DTC with the diagnostic tester

Result: P2603: voltage of cooling pump control circuit is too high

Prompt:

Following problem might exist

1) The circuit of cooling pump signal connecting to ECU is shorted to power supply; use a
multimeter to measure the voltage of ECU pin.

DTC: U0121: communication failure between ECM and ABS

DTC: U0164: communication failure between ECM and A/C controller

DTC: U0168: communication failure between ECM and keyless system

Step 1: Read DTC with the diagnostic tester

The results are:

U0121: communication failure between ECM and ABS

U0164: communication failure between ECM and A/C controller

U0168: communication failure between ECM and keyless system

Prompt:

Following problem might exist

1) Check if the system has problem, and if the communication line has short circuit or open
circuit.

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5. Diagnostic Procedures of affected.

Servicing TB10 System as per
Diagnosis help:
Symptoms of Malfunction
1. Confirm there is no engine malfunction
Preliminary check shall be made before record;
troubleshooting as per the symptoms of
malfunction: 2. Confirm the symptoms of complained
malfunction exist;
1. Ensure the engine malfunction indicator
works normally; 3. No abnormalities have been found after
check by following the steps mentioned
2. Check with the electric diagnostic tester above;
to ensure no malfunction record.
4. Do not neglect the effect of vehicle
3. Confirm the symptoms of malfunction maintenance, cylinder pressure, ignition
complained by the owner of car exist timing and fuel on the system during
and verify the conditions where such servicing;
malfunction occurs.
5. Replace the ECU and make a test.
Then, visual inspection shall be made:
f the malfunction disappears, the ECU is
(1) Check the fuel pipeline for leakage; in trouble; if it still exists, replace with the
original ECU and repeat the steps to service
(2) Check the vacuum pipeline for breakage,
it.
twist and improper connection;
This manual lists the following 14 common
(3) C h e c k t h e i n t a k e a i r p i p e l i n e f o r
malfunctions and the general flow of
blockage, leakage, compression or
diagnosis is provided for reference:
damage;
1. Engine running slowly or not running
(4) Check if the appearance of the ignition
when started
coil has bulge and if the ignition
sequence is correct; 2. Engine cannot be started with starter
running
(5) Check if the pipeline of cooling system is
clogged or leaks; 3. Hard to start when the engine is hot
(6) C h e c k i f t h e a p p e a r a n c e o f t h e 4. Hard to start when the engine is cold
supercharger is abraded, if the
components of the turbine shaft rotate 5. Hard to start at normal engine speed any
freely, and if the impeller is damaged by time
the impact;
6. Engine normally started, yet idling
(7) Check if the turbine housing and piping unstable any time
joints leak exhaust, and if the air intake
system leaks; 7. Engine normally started, idling unstable
during heating
(8) Check the ground point of wiring harness
for dirt and looseness; 8. Engine normally started, yet idling
unstable after heating
(9) Check the connectors of sensors and
actuators for looseness or poor contact. 9. Engine normally started, yet idling
unstable or stalling under partial load
Important Notice: If the symptoms mentioned (e.g. A/C turned on)
above exist, maintenance and repair shall be
made against such malfunction; otherwise, 10. Engine normally started, yet idling at a
the subsequent troubleshooting may be higher speed

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11. Engine running slowly or stalling during acceleration

12. Slow response in acceleration

13. Sluggish acceleration and poor performance

14. Jerk or jitter when the vehicle is accelerating or at constant speed

1. Engine running slowly or not running when started

General faulty parts: 1. Battery; 2. Start motor; 3. Wire harness or ignition switch; 4. Fuse or relay
in engine room fuse and relay box or instrument panel fuse and relay box; 5. Engine mechanical
part.

General diagnostic flow:

No. Operating Steps Test Result Follow-up Steps

Yes Next step

Check if the voltage between two terminals of battery is about 8~12V with a
1
multimeter when the engine is started.
No Replace battery

Yes Next step

Keep the ignition switch at the starting position and check if positive
2
terminal of start motor has an over 8V voltage with a multimeter. Repair or replace
No
the wire harness
Repair or replace
Yes
Remove the start motor and check its working condition. Check if it is the start motor
3
broken or stuck due to poor lubrication.
No Next step

Remove the positive wire and negative wire of the battery, and check Yes Replace the fuse
whether the fuses in the engine room fuse and relay box with a multimeter:
F1/5, F1/9, F1/18, F1/22-1, F1/23-2, and the fuses in instrument panel
4
fuse and relay box: F2/3, F2/14, F2/22, F2/23, F2/24, F2/25, F2/26 are
No Next step
turned on, and check if any fuse is blown out. (See Appendix 7.4 for the
description of distributor box fuse and relay)
When the engine is switched on, check whether the relays in the instrument Repair or replace
Yes
panel fuse and relay box: K2-1, K2-4, K2-6 are energized; when the engine the relay
5
is started, check whether the relay K2-7 in the instrument panel fuse and
No Next step
relay box is energized.
Replace with
If the malfunction only occurs in winter, check if excessive resistance is Yes lubricant of
6 caused to the start motor because improper engine lubricant and gear box proper class
oil are selected.
No Next step
Service
the internal
Yes
Check if the excessive mechanical resistance inside the engine causes the resistance of
7
start motor not to rotate or rotate slowly. engine
Repeat above
No
steps

2. Engine cannot be started with starter running

General faulty parts: 1. Fuel tank without fuel; 2. High pressure fuel pump; 3. Low pressure fuel
pump; 4. Speed sensor; 5. Ignition coil; 6. Fuse or relay in engine room fuse and relay box or
instrument panel fuse and relay box; 7. Engine mechanical part.

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No. Operating Steps Test Result Follow-up Steps

Connect the fuel pressure gauge (oil inlet of high pressure fuel rail as Yes Next step
1 connecting point), start the engine and check if the fuel pressure is about
Service the oil
600kPa in idle condition. No
supply system
Yes Next step
Connect the EFI diagnostic tester, and check if the pressure of the high Service or
2
pressure fuel pump is about 65bar. replace the high
No
pressure fuel
pump
Clean or replace
Yes
Remove the fuel injector and check it for leakage or blockage with a the fuel injector
3
dedicated cleaning analyzer.
No Next step

Yes Next step

Connect the diagnostic tester for EFI system, observe the data item“Engine Service the
4
Speed”, start the engine and observe if there is speed signal output. crankshaft
No
position sensor
line
Pull out an ignition coil from one cylinder and also pull out the
Yes Next step
corresponding injector nozzle plug, connect a spark plug and keep its
5
electrodes about 5mm away from the engine body, start the engine and Service the
No
check for blue high-pressure fire. ignition system
Remove the positive wire and negative wire of the battery, and check
Yes Replace the fuse
whether the fuses in the engine room fuse and relay box with a multimeter:
F1/9, F1/18, and the fuses in instrument panel fuse and relay box: F2/3,
6
F2/14, F2/23, F2/24, F2/25, F2/26 are turned on, and check if any fuse is
No Next step
blown out. (See Appendix 7.4 for the description of distributor box fuse and
relay)
Repair or replace
Yes
When the engine is switched on, check whether the relays in the instrument the relay
7
panel fuse and relay box: K2-1, K2-4, K2-6 are energized.
No Next step
Troubleshoot
the engine
Yes
Check the pressure of all engine cylinders and observe the engine cylinder mechanical
8
for insufficient pressure. malfunction
No Next step
Connect the EFI system connector, turn on the ignition switch, check
Yes Diagnosis help
whether uninterrupted power supply, ignition switch, non-persistent power
9 supply and the pin power supply of the non-continuous power supply are
Service the
normal; check whether the ignition grounding, electronic grounding, and No
relevant line
power grounding pin 1# are normal.

3. Hard to start when the engine is hot

General faulty parts: 1. Fuel with water; 2. High pressure fuel pump; 3. Low pressure fuel pump; 4.
Coolant temperature sensor; 5. Ignition coil.

General diagnostic flow:

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No. Operating Steps Test Result Follow-up Steps

Connect the fuel pressure gauge (oil inlet of high pressure fuel rail as Yes Next step
1 connecting point), start the engine and check if the fuel pressure is about
Service the oil
600kPa in idle condition. No
supply system
Pull out an ignition coil from one cylinder and also pull out the
Yes Next step
corresponding injector nozzle plug, connect a spark plug and keep its
2
electrodes about 5mm away from the engine body, start the engine and Service the
No
check for blue high-pressure fire. ignition system
Service the line
Unplug the connector of coolant temperature sensor, start the engine and
Yes or replace the
observe if it starts successfully. (Or replace the coolant temperature sensor
3 sensor
with a 300Ω resistor to be connected in series and then observe if the
engine starts successfully.) No Next step

No Next step
Check the fuel and observe if the malfunction is caused just after fueling
4 Yes Replace the fuel
up.
No Next step

Connect the adapter of EFI system, turn on the ignition switch and check if Yes Diagnosis help
5 the power supply for 113#, 112#, 3#, 119# and 120# pin is normal; check if
Service the
the 51#, 58#, 2#, 100#, 103#, 104# and 108# pin are normally grounded. No
relevant line

4. Hard to start when the engine is cold

General faulty parts: 1. Fuel with water; 2. High pressure fuel pump; 3. Low pressure fuel pump;
4. Coolant temperature sensor; 5. Fuel injector; 6. Ignition coil; 7. Electronic throttle; 8. Engine
mechanical parts.

General diagnostic flow:

No. Operating Steps Test Result Follow-up Steps

Connect the fuel pressure gauge (oil inlet of high pressure fuel rail as Yes Next step
1 connecting point), start the engine and check if the fuel pressure is about
Service the oil
600kPa in idle condition. No
supply system
Pull out an ignition coil from one cylinder and also pull out the
Yes Next step
corresponding injector nozzle plug, connect a spark plug and keep its
2
electrodes about 5mm away from the engine body, start the engine and Service the
No
check for blue high-pressure fire. ignition system
Service the line
Unplug the connector of coolant temperature sensor, start the engine and
Yes or replace the
observe if it starts successfully. (Or replace the coolant temperature sensor
3 sensor
with a 2500Ω resistor to be connected in series and then observe if the
engine starts successfully.) No Next step

Yes Clean the throttle

4 Press the accelerator pedal down gently and observe if it is easy to start.
No Next step
Replace the
Yes
Remove the fuel injector and check it for leakage or blockage with a faulty part
5
dedicated cleaning analyzer.
No Next step

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Yes Replace the fuel

Check the fuel and observe if the malfunction is caused just after fueling
6
up.
No Next step
Troubleshoot
the engine
Yes
Check the pressure of all engine cylinders and observe the engine cylinder mechanical
7
for insufficient pressure. malfunction
No Next step

Connect the adapter of EFI system, turn on the ignition switch and check if Yes Diagnosis help
8 the power supply for 113#, 112#, 3#, 119# and 120# pin is normal; check if
Service the
the 51#, 58#, 2#, 100#, 103#, 104# and 108# pin are normally grounded. No
relevant line

5. Hard to start at normal engine speed any time

General faulty parts: 1. Fuel with water; 2. High pressure fuel pump; 3. Low pressure fuel pump; 4.
Coolant temperature sensor; 5. Fuel injector; 6. Ignition coil; 7. Electronic throttle assembly; 8. Air
intake duct; 9. Ignition timing; 10. Spark plug; 11. Engine mechanical parts.

General diagnostic flow:

No. Operating Steps Test Result Follow-up Steps

Service the air
Yes
intake system
1 Check the air filter for blockage and the air intake duct for air leakage.
No Next step

Connect the fuel pressure gauge (oil inlet of high pressure fuel rail as Yes Next step
2 connecting point), start the engine and check if the fuel pressure is about
Service the oil
600kPa in idle condition. No
supply system
Pull out an ignition coil from one cylinder and also pull out the
Yes Next step
corresponding injector nozzle plug, connect a spark plug and keep its
3
electrodes about 5mm away from the engine body, start the engine and Service the
No
check for blue high-pressure fire. ignition system
Yes Next step
Check the spark plug for each cylinder and observe if its model and
4
clearance meet the specifications.
No Adjust or replace
Service the line
Yes or replace the
Unplug the connector of coolant temperature sensor, start the engine and
5 sensor
observe if it starts successfully.
No Next step

Yes Clean the throttle

6 Press the accelerator pedal down gently and observe if it is easy to start.
No Next step
Replace the
Yes
Remove the fuel injector and check it for leakage or blockage with a faulty part
7
dedicated cleaning analyzer.
No Next step

Yes Replace the fuel

Check the fuel and observe if the malfunction is caused just after fueling
8
up.
No Next step

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Troubleshoot
the engine
Yes
Check the pressure of all engine cylinders and observe the engine cylinder mechanical
9
for insufficient pressure. malfunction
No Next step

Yes Next step

Check if the ignition order and ignition timing of the engine meet the
10
specifications. Service the
No
ignition timing
Connect the adapter of EFI system, turn on the ignition switch and check if Yes Diagnosis help
11 the power supply for 113#, 112#, 3#, 119# and 120# pin is normal; check if
Service the
the 51#, 58#, 2#, 100#, 103#, 104# and 108# pin are normally grounded. No
relevant line

6. Engine normally started, yet idling unstable any time

General faulty parts: 1. Fuel with water; 2. Fuel injector; 3. Spark plug; 4. Electronic throttle valve
assembly; 5. Air intake duct; 6. Ignition timing; 7. Spark plug; 8. Engine mechanical part.

General diagnostic flow:

No. Operating Steps Test Result Follow-up Steps

Service the air
Yes
intake system
1 Check the air filter for blockage and the air intake duct for air leakage.
No Next step

Yes Next step

Check the spark plug for each cylinder and observe if its model and
2
clearance meet the specifications.
No Adjust or replace

Yes Clean
3 Check whether the electronic throttle body has carbon deposit.
No Next step
Replace the
Yes
Remove the fuel injector and check it for leakage, blockage or poor flow faulty part
4
with a dedicated cleaning analyzer.
No Next step

Yes Replace the fuel

Check the fuel and observe if the malfunction is caused just after fueling
5
up.
No Next step
Troubleshoot
the engine
Yes
mechanical
6 Check the pressure of all engine cylinders and observe if it varies greatly.
malfunction
No Next step

Yes Next step

Check if the ignition order and ignition timing of the engine meet the
7
specifications. Service the
No
ignition timing
Connect the adapter of EFI system, turn on the ignition switch and check if Yes Diagnosis help
8 the power supply for 113#, 112#, 3#, 119# and 120# pin is normal; check if
Service the
the 51#, 58#, 2#, 100#, 103#, 104# and 108# pin are normally grounded. No
relevant line

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7. Engine normally started, idling unstable during heating

General faulty parts: 1. Fuel with water; 2. Coolant temperature sensor; 3. Spark plug; 4.
Electronic throttle; 5. Air intake duct; 6. Engine mechanical part.

General diagnostic flow:

No. Operating Steps Test Result Follow-up Steps

Service the air
Yes
intake system
1 Check the air filter for blockage and the air intake duct for air leakage.
No Next step

Yes Next step

Check the spark plug for each cylinder and observe if its model and
2
clearance meet the specifications.
No Adjust or replace
Clean relevant
Yes
parts
3 Check whether the electronic throttle body has carbon deposit.
No Next step
Service the line
Yes or replace the
Unplug the connector of coolant temperature sensor, start the engine and
4 sensor
observe if unstable idling occurs when the engine is heated.
No Next step
Replace the
Yes
Remove the fuel injector and check it for leakage, blockage or poor flow faulty part
5
with a dedicated cleaning analyzer.
No Next step

Yes Replace the fuel

Check the fuel and observe if the malfunction is caused just after fueling
6
up.
No Next step
Troubleshoot
the engine
Yes
mechanical
7 Check the pressure of all engine cylinders and observe if it varies greatly.
malfunction
No Next step

Connect the adapter of EFI system, turn on the ignition switch and check if Yes Diagnosis help
8 the power supply for 113#, 112#, 3#, 119# and 120# pin is normal; check if
Service the
the 51#, 58#, 2#, 100#, 103#, 104# and 108# pin are normally grounded. No
relevant line

8. Engine normally started, yet idling unstable after heating

General faulty parts: 1. Fuel with water; 2. Coolant temperature sensor; 3. Spark plug; 4.
Electronic throttle; 5. Air intake duct; 8. Engine mechanical part.

General diagnostic flow:

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No. Operating Steps Test Result Follow-up Steps

Service the air
Yes
intake system
1 Check the air filter for blockage and the air intake duct for air leakage.
No Next step

Yes Next step

Check the spark plug for each cylinder and observe if its model and
2
clearance meet the specifications.
No Adjust or replace
Clean relevant
Yes
parts
3 Check whether the throttle body has carbon deposit.
No Next step
Service the line
Yes or replace the
Unplug the connector of coolant temperature sensor, start the engine and
4 sensor
observe if unstable idling occurs when the engine is heated.
No Next step
Replace the
Yes
Remove the fuel injector and check it for leakage, blockage or poor flow faulty part
5
with a dedicated cleaning analyzer.
No Next step

Yes Replace the fuel

Check the fuel and observe if the malfunction is caused just after fueling
6
up.
No Next step
Troubleshoot
the engine
Yes
mechanical
7 Check the pressure of all engine cylinders and observe if it varies greatly.
malfunction
No Next step

Connect the adapter of EFI system, turn on the ignition switch and check if Yes Diagnosis help
8 the power supply for 113#, 112#, 3#, 119# and 120# pin is normal; check if
Service the
the 51#, 58#, 2#, 100#, 103#, 104# and 108# pin are normally grounded. No
relevant line

9. Engine normally started, yet idling unstable or stalling under partial load (e.g. A/C turned
on)

General faulty parts: 1. A/C system; 2. Electronic throttle; 3. Fuel injector.

General diagnostic flow:

No. Operating Steps Test Result Follow-up Steps

Clean relevant
Yes
parts
1 Check whether the electronic throttle body has carbon deposit.
No Next step
Observe if the engine output power increases when the A/C system is
Yes To Step 4
started, that is, to observe the change in ignition advance angle, fuel
2
injection pulse width and air intake flow with the diagnostic tester for EFI
No Next step
system.

Connect the adapter of EFI system, disconnect the cable of 54# pin of ECU Yes Next step
3 and check if there is high level signal at the end of wire harness when the
Service the A/C
A/C system is turned on. No
system

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Yes Next step

Check if the A/C system pressure, the compressor electromagnetic clutch
4
and the A/C compressor pump are normal. Service the A/C
No
system
Replace the
Yes
Remove the fuel injector and check it for leakage, blockage or poor flow faulty part
5
with a dedicated cleaning analyzer.
No Next step

Connect the adapter of EFI system, turn on the ignition switch and check if Yes Diagnosis help
6 the power supply for 113#, 112#, 3#, 119# and 120# pin is normal; check if
Service the
the 51#, 58#, 2#, 100#, 103#, 104# and 108# pin are normally grounded. No
relevant line

10. Engine normally started, yet idling at a higher speed

General faulty parts: 1. Electronic throttle valve assembly; 2. Vacuum tube; 3. Coolant
temperature sensor; 4. Ignition timing.

General diagnostic flow:

No. Operating Steps Test Result Follow-up Steps

Replace the
Yes
accelerator pedal
1 Check whether the signal output of electronic accelerator pedal is normal
No Next step
Service the air
Yes
intake system
2 Check the air intake system and the connected vacuum line for leakage.
No Next step
Clean relevant
Yes
parts
3 Check whether the electronic throttle body has carbon deposit.
No Next step
Service the line
Yes or replace the
Unplug the connector of coolant temperature sensor, start the engine and
4 sensor
observe if it idles at a higher speed.
No Next step

Yes Next step

5 Check if the ignition timing of the engine meets the specifications.
Service the
No
ignition timing
Connect the adapter of EFI system, turn on the ignition switch and check if Yes Diagnosis help
6 the power supply for 113#, 112#, 3#, 119# and 120# pin is normal; check if
Service the
the 51#, 58#, 2#, 100#, 103#, 104# and 108# pin are normally grounded. No
relevant line

11. Engine running slowly or stalling during acceleration

General faulty parts: 1. Fuel with water; 2. Intake air pressure sensor; 3. Spark plug; 4. Electronic
throttle valve assembly; 5. Air intake duct; 6. Idle speed regulator; 7. Fuel injector; 8. Ignition
timing; 9. Exhaust pipe; 10. Turbocharger

General diagnostic flow:

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No. Operating Steps Test Result Follow-up Steps

Service the air
Yes
intake system
1 Check the air filter for blockage.
No Next step

Connect the fuel pressure gauge (oil inlet of high pressure fuel rail as Yes Next step
2 connecting point), start the engine and check if the fuel pressure is about
Service the oil
600kPa in idle condition. No
supply system
Yes Next step
Check the spark plug for each cylinder and observe if its model and
3
clearance meet the specifications.
No Adjust or replace
Clean relevant
Yes
parts
4 Check whether the electronic throttle body has carbon deposit.
No Next step

Yes Next step

Check if the intake air pressure sensor and the electronic throttle body as
5 Service the line
well as their lines are normal.
No or replace the
sensor
Replace the
Yes
Remove the fuel injector and check it for leakage or blockage with a faulty part
6
dedicated cleaning analyzer.
No Next step

Yes Replace the fuel

Check the fuel and observe if the malfunction is caused just after fueling
7
up.
No Next step

Yes Next step

Check if the ignition order and ignition timing of the engine meet the
8
specifications. Service the
No
ignition timing
Yes Next step
9 Check the bleeding pipe for smooth bleeding.
Repair or replace
No
the bleeding pipe
Connect the adapter of EFI system, turn on the ignition switch and check if Yes Next step
10 the power supply for 113#, 112#, 3#, 119# and 120# pin is normal; check if
Service the
the 51#, 58#, 2#, 100#, 103#, 104# and 108# pin are normally grounded. No
relevant line
Check the working condition of the turbocharger, whether the supercharging Yes Diagnosis help
Service
11 is insufficient or air leaks.
No turbocharger or
Yes replace the parts

12. Slow response in acceleration

General faulty parts: 1. Fuel with water; 2. Intake air pressure sensor; 3. Spark plug; 4. Electronic
throttle valve assembly; 5. Air intake duct; 6. Fuel injector; 7. Ignition timing; 8. Exhaust pipe; 9.
Turbocharger

General diagnostic flow:

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No. Operating Steps Test Result Follow-up Steps

Service the air
Yes
intake system
1 Check the air filter for blockage.
No Next step

Connect the fuel pressure gauge (oil inlet of high pressure fuel rail as Yes Next step
2 connecting point), start the engine and check if the fuel pressure is about
Service the oil
600kPa in idle condition. No
supply system
Yes Next step
Check the spark plug for each cylinder and observe if its model and
3
clearance meet the specifications.
No Adjust or replace
Clean relevant
Yes
parts
4 Check whether the throttle body has carbon deposit.
No Next step

Yes Next step

5 Check whether the line of the intake air pressure sensor is normal. Service the line
No or replace the
sensor
Replace the
Yes
Remove the fuel injector and check it for leakage or blockage with a faulty part
6
dedicated cleaning analyzer.
No Next step

Yes Replace the fuel

Check the fuel and observe if the malfunction is caused just after fueling
7
up.
No Next step

Yes Next step

Check if the ignition order and ignition timing of the engine meet the
8
specifications. Service the
No
ignition timing
Yes Next step
Check whether the exhaust pipe is smooth, and check whether the
9
turbocharger leaks air or the supercharging is insufficient.
No Repair or replace

Connect the adapter of EFI system, turn on the ignition switch and check if Yes Diagnosis help
10 the power supply for 113#, 112#, 3#, 119# and 120# pin is normal; check if
Service the
the 51#, 58#, 2#, 100#, 103#, 104# and 108# pin are normally grounded. No
relevant line

13. Sluggish acceleration and poor performance

General faulty parts: 1. Fuel with water; 2. Intake air pressure sensor; 3. Spark plug; 4. Ignition
coil; 5. Electronic throttle valve assembly; 6. Air intake duct; 7. Fuel injector; 8. Ignition timing; 9.
Exhaust pipe; 10. Turbocharger

General diagnostic flow:

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No. Operating Steps Test Result Follow-up Steps

Yes Repair
Check for slipping clutch, low tire pressure, braking drag, incorrect tire size,
1
improper four wheel alignment, etc.
No Next step
Service the air
Yes
intake system
2 Check the air filter for blockage.
No Next step

Connect the fuel pressure gauge (oil inlet of high pressure fuel rail as Yes Next step
3 connecting point), start the engine and check if the fuel pressure is about
Service the oil
600kPa in idle condition. No
supply system
Pull out an ignition coil from one cylinder and also pull out the
Yes Next step
corresponding injector nozzle plug, connect a spark plug and keep its
4
electrodes about 5mm away from the engine body, start the engine and Service the
No
check for blue high-pressure fire. ignition system
Yes Next step
Check the spark plug for each cylinder and observe if its model and
5
clearance meet the specifications.
No Adjust or replace
Clean relevant
Yes
parts
6 Check whether the electronic throttle has carbon deposit.
No Next step

Yes Next step

Check if the intake air pressure sensor and the throttle position sensor as
7 Service the line
well as their lines are normal;
No or replace the
sensor
Replace the
Yes
Remove the fuel injector and check it for leakage or blockage with a faulty part
8
dedicated cleaning analyzer.
No Next step

Yes Replace the fuel

Check the fuel and observe if the malfunction is caused just after fueling
9
up.
No Next step

Yes Next step

Check if the ignition order and ignition timing of the engine meet the
10
specifications. Service the
No
ignition timing
Yes Next step
11 Check the bleeding pipe for smooth bleeding.
Repair or replace
No
the bleeding pipe
Connect the adapter of EFI system, turn on the ignition switch and check if Yes Next step
12 the power supply for 113#, 112#, 3#, 119# and 120# pin is normal; check if
Service the
the 51#, 58#, 2#, 100#, 103#, 104# and 108# pin are normally grounded. No
relevant line
Yes Diagnosis help
Check the working condition of the turbocharger, whether the supercharging
13 Service the line
is insufficient or air leaks.
No or replace the
parts

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14. Jerk or jitter when the vehicle is accelerating or at constant speed

General faulty parts: 1. Fuel or tires do not meet the technical requirements; 2. Air filter and
inlet clogged; 3. Excessive carbon deposit in electronic throttle body; 4. Oil pressure too low
or no oil pressure; 5. Ignition coil; 6. Spark plug;7. Fuel injector; 8. Ignition timing; 9. Exhaust
pipe; 10. Supercharger; 11. Carbon canister is clogged or carbon canister electromagnetic valve
malfunctions; 12. Sensors and line malfunction.

General diagnostic flow:

Test
No. Operating Steps Follow-up Steps
Result
Replace or
Check if the fuel, tire pressure, tire size, and wheel alignment Yes
1 repair
comply with the technical requirements.
No Next step
Replace the air
filter, and clean
Check the air filter for blockage and the air intake duct for Yes
2 the air intake
excessive carbon deposit. duct
No Next step
Clean or replace
Yes
3 Check the electronic throttle for excessive carbon deposit. the throttle
No Next step

Connect the fuel pressure gauge (oil inlet of high pressure fuel Yes Next step
4 pump as connecting point), start the engine and check if the fuel Service the oil
pressure is about 600kPa in idle condition. No
supply system
Pull out an ignition coil from one cylinder and also pull out the Yes Next step
corresponding injector nozzle plug, connect a spark plug and
5 Service the
keep its electrodes about 5mm away from the engine body, start No
the engine and check for blue high-pressure fire. ignition system
Check the spark plug for each cylinder, observe if its model Replace the
Yes
6 and clearance meet the specifications, and if carbon deposit is spark plug
excessive. No Next step
Replace the
Remove the fuel injector and check it for leakage or blockage Yes
7 faulty part
with a dedicated cleaning analyzer.
No Next step

Check the fuel and observe if the malfunction is caused just after Yes Replace the fuel
8
fueling up. No Next step

Yes Next step

Check if the ignition order and ignition timing of the engine meet
9 Service the
the specifications. No
ignition timing
Yes Next step
10 Check the bleeding pipe for smooth bleeding. Repair or
No replace the
exhaust pipe

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Check the working condition of the turbocharger, whether the Yes Diagnosis help
11
supercharging is insufficient or air leaks. No Next step
Replace the
Yes
12 Check if the carbon canister is blocked and can’t work normally carbon canister
No Next step

Yes Next step

Turn on the ignition switch, control the carbon canister Repair or
electromagnetic valve in open or closed state with the diagnostic replace the
13
tester, and check if the carbon canister electromagnetic valve No carbon canister
operates properly according to the instruction. electromagnetic
valve
Yes Next step
Check if the intake air pressure sensor and the throttle position Service the line
14
sensor as well as their lines are normal; No or replace the
sensor
Connect the adapter of EFI system, turn on the ignition switch Yes Next step
and check if the power supply for 113#, 112#, 3#, 119# and 120#
15 Service the
pin is normal; check if the 51#, 58#, 2#, 100#, 103#, 104# and No
108# pin are normally grounded. relevant line

6. Self-learning and Operating Instructions

6.1 Idle Flow Self-learning

After ECU is replaced or program is refreshed, idle flow self-learning is required. If the self-
learning isn’t conducted, the following phenomena may occur:

1. The engine start-up speed has large fluctuation, and even high idle speed or flameout may
occur;

2. The engine speed fluctuation is large when A/C is switched on

Self-learning can be completed in accordance with the following methods:

1. Start the engine;

2. Turn off all electrical loads and air conditioner, and the engine runs about 10~15s stably;

3. After A/C is switched on and A/C clutch pulls in, A/C starts working, and switch off the A/C
after 10~15s;

4. Flameout 10s to complete the self-learning.

6.2 Electronic Throttle Self-learning

This self-learning has two objectives: first, learn the AD values of initial position and fully closed
position of the throttle, used to calculate the initial opening and current opening; secondly, test if
the return spring is invalid.

Self-learning includes brief mode and complete mode. Brief self-learning is only to test the
spring and learn the opening of initial position, but doesn’t learn the AD value of the fully
closed position. Complete self-learning not only tests the spring, but also learns the AD values

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of the initial position and the fully closed position. When replacing the electronic throttle, the new
electronic throttle requires complete self-learning.

At least one self-learning mode is enabled after each power on; if the conditions of complete
self-learning are met, the complete mode is enabled, or else the brief mode is enabled; the self-
learning is always executed when the ignition switch is turned on. When switching to “ON”,
ECU will read the throttle data in EEPROM, and determine the self-learning mode according to
these data. If the self-learning conditions are met, it will carry out the corresponding type of self-
learning, and will exit if any of the conditions are not met in the self-learning process. Brief self-
learning takes 3s, and complete self-learning takes 6s. After self-learning, turn off the power, and
do not turn on in 10s to ensure that the learned data will be stored in EEPROM normally.

The self-learning conditions are as follows:

1. No throttle position sensor malfunction

2. The engine does not run

3. The vehicle is stationary (no speed)

4. The battery voltage is greater than 6V

5. The water temperature is 5° C~95° C

6. The intake air temperature is 0° C~95° C

Self-learning stops if any of the conditions are not met.

Conditions of complete self-learning:

1. The electronic throttle data in EEPROM are unreasonable

2. Previous self-learning is interrupted

3. When turning on, the AD values of the initial position of the throttle valve sheet have larger
deviation with the calibration value.

After turning on, if any one of the conditions are met, complete self-learning mode will be enabled,
and the electronic throttle starts complete self-learning.

When replacing new electronic throttle, EEPROM may also store on the relevant data of previous
electronic throttle, and these data can not enable complete self-learning mode. In order to ensure
conditions of complete self-learning are met, the self-learning must be interrupted forcibly. Ensure
that:

1. Stepping on the brake or clutch, turn on the power and start the engine. After starting the
engine, turn off the power for over 10s (this step is to interrupt the self-learning, and ensure
that the complete self-learning conditions are met the next time).

2. Turn on the power, but do not to start the engine, let the throttle learn for 6s, and turn off the
power for over 10s.

The operation of the electronic throttle valve sheet can be used to determine if a completely self-
learning has been conducted. Valve operation condition in the complete self-learning process
of the electronic throttle: after power-on, the electronic throttle valve sheet moves to a certain
opening position toward the large opening and maintains about 1s, and then gradually moves to
the fully closed position and maintains about 1s, and finally returns to the natural opening. If the
complete self-learning isn’t conducted, the valve sheet won’t move to the fully closed position.

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7. Usage of Electric Diagnostic Tester

The independently developed BYD ED400 electric diagnostic tester for example, the fault
diagnostic analysis for TI EFI system is described below. With the launch of new models and
program update, the display content and function may vary.

The values and content in this chapter are for reference only. The actual diagnostic procedure
shall prevail.
7.1 Operation Panel of Electric Diagnostic Tester

• The left side of the panel is an LCD, which is used to display a variety of diagnostic
information.

• The right side of the panel are operation buttons, as shown below:

7.2 Key Functions

Number key 0-9: menu selection; digital input.

Direction keys ↑↓←→ : ↑ and ↓ for menu selection; ← and → for page flipping; in case of digital
input, press ↑ to add 1, ↓ to deduct 1 and ← to backspace and clear the previous digit; in case of
action test for components, press ← to shut down and → to enable or start.

Reset key RST: system reset. Notice: Use it with caution. Press and hold this key for 1~2 seconds
and then release it.

Return/Exit key ESC: return to parent directory; exit the current function page; exit current setting.

Confirmation key OK: enter subdirectory; confirm to perform a certain function.

Multifunction key F1 and F2: F1 is used to display help; F2 is used to print the current page; these
two keys can be used as auxiliary input keys in special conditions, like -/+. Refer to the relevant
prompts.

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7.3 Functions of the Electric Diagnostic

Tester Please select function
1. Diagnosis for specific model
I. Self diagnosis
2. Diagnostic card burning
Mainly include: read DTC and clear DTC; 3. Diagnostic tester version information
4. Diagnostic tester setting
II. System parameter display
5. Diagnostic tester operating guide
Mainly include: Main parameters, parameters
and sensor signal voltage;

III. System state

Mainly include: programming state, cooling

system, stable condition, dynamic condition,
emission control, oxygen sensor, idle speed,
malfunction indicator, emergency operation, Press [ ] to move up
and air conditioning; Press [ ] to move down
Press [OK] to enter the submenu
IV. Actuator test

Mainly include: malfunction indicator, fuel

pump, air conditioning relay, fan control, 4. Select model diagnostic;
ignition test, and single-cylinder fuel cut-off;
5. Enter the diagnostic model selection
V. Odometer interface;

Mainly include: vehicle mileage, and driving 6. Select the model for diagnosis (e.g. G6);
time;
7. Enter the diagnostic system selection
VI. Version information interface;

Mainly include: frame number (optional), ECU

hardware number, and ECU software number. Please select system

7.4 Usage of the Electric Diagnostic 1. EMS

Tester 2. AMT
3. ABS
1. Connect the diagnostic line;
4. SRS
2. Use the push-to-start button to turn
the power switch of the vehicle to ON
position;

3. Enter the diagnostic function selection

interface;

Press [ ] to move up
Press [ ] to move down
Press [OK] to enter the submenu
Press [ESC] to return to previous menu

8. Select Engine Management System;

9. Enter into the interface to select engine

management system;

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10. Select “TI Engine Management

System”; DTC

TI Engine Management System

No trouble with system

1. Read computer version

2. Read DTC
3. Clear DTC
4. Read data stream
5. Action test for components

Press any key to return

Press [ ] to move up
Press [ ] to move down
Press [OK] to enter the submenu
If trouble with system
Press [ESC] to return to previous menu
All the DTCs and relevant trouble information
10.1 Read PC version will be listed in the “Information Bar”, as
shown in the figure below.
The computer version information is a group
of numbers defined by the manufacturer to
identify some basic information, like Vehicle DTC
Identification Number.

10.2 Read DTC 1. P0106: intake air pressure sensor signal

malfunction
Malfunction detected by ECU can be 2. P0107: voltage of intake air pressure
displayed in the form of specific code (DTC). sensor circuit is too low
See relevant industry standards for the 3. P0108: voltage of intake air pressure
coding specifications of DTC. sensor circuit is too high
4. P0111: intake air temperature sensor
If no trouble with system
signal malfunction
You will be prompted with “No Trouble with 5. P0685: DTC not defined
System” by BYD-ED400, as shown in the
figure below.
Press [←] to page up
Press [→] to page down
Press [F2] to print
Press [ESC] to exit

Trouble information is divided into four parts.

The part in the front is just the serial number;
the second part is DTC in such a form as
“P0122”, wherein the first letter “P”
indicating the engine malfunction makes a
DTC with the last four digits “0122” and
the DTC is compiled as per relevant standard;

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the third part is enclosed by parentheses,

indicating the malfunction status, “Current”, Clear DTC
“Historical” or “Intermittent”; “Current”
means a current malfunction that cannot
be cleared by selecting “Clear DTC”;
“Historical” means a historical malfunction
that yet has been solved before this DTC cleared
diagnosis and can be cleared by selecting
“Clear DTC”; “Intermittent” means an
intermittent malfunction that may be caused
by poor contact and can also be cleared by
selecting “Clear DTC”; at last, the fourth
part gives a brief and complete introduction
to the malfunction; if some malfunction
information is not contained in BYD-ED400,
you will be prompted with “DTC Not
Defined”. In this case, please contact After-
service Department of BYD. Press any key to return

“Page:1/2” at the upper right corner of

screen means the received malfunction
information is shown on two pages and the 10.4 Read data stream
current page is the first one; to view other This function is used to show the data status
information, users can press [?] to turn to of the engine, including current engine speed
page 2, following the prompts shown in the and vehicle speed.
“Help Bar”. Also, users can press [ ← ] to
turn to page 1. The interface of successful communication
is shown in the figure below. The first page
10.3 Clear DTC is displayed now. To view other data content,
It is intended to clear some historical or users can turn to a specific page by pressing
intermittent malfunctions recorded in ECU. ← and → .
If DTC is successfully cleared, “DTC
Cleared” will be displayed as shown in the Data stream
figure on the right. You are recommended
to repeat the action twice or three times to
DTC number: 0
ensure DTC is cleared completely.
Power voltage: 12.6V
Engine speed: 0RPM
Target idle speed (without compensation): 0RPM
Target idle speed (with compensation): 0RPM
Vehicle speed: 0km/h
Coolant temperature SNS voltage: 2.50V
Coolant temperature: 45°C
Intake temperature SNS voltage: 1.38V
Intake temperature: 36°C

Press [1] to change view mode

Press [2] to change dot-drawing mode
Press [F2] to print the current page
Press [ESC] to exit

10.5 Component action test

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Component action tests include two control

modes, i.e. switching variable and control Component action test
variable, as shown in the figure below. The
action for each variable is carried out in Malfunction indicator: ON
different ways, which will be described below. Fuel pump relay:
Low-speed fan:
Component action test High-speed fan:
A/C relay:
Tooth signal self-learning:
BLM signal self-learning:
Fuel open-loop:
1. Switching variable Catalytic converter offline:
2. Control variable Oxygen sensor:

Press [↑] or [↓] to select a test item

Press [←] to shut down; press [→] to open
Press [F2] to print
Press [ESC] to exit

• Control variable
Press [ ] to move up
Press [ ] to move down It refers to some setting variables. By setting
Press [OK] to enter the submenu these variables, the internal variables of ECU
Press [ESC] to return to previous menu can be changed so as to change the working
conditions of engine.
• Switching variable
“★” indicates the item can be set now. To
It means only two states for these variables: select a variable to be set, users can press ↑
ON or OFF, so users just need to perform and ↓ .
simple operations to complete relevant action.
The user can press [OK] to enter and set an
“★” indicates the variable currently controlled. option.
At the same time, the user expected
operation state is displayed in the right: ON Component action test
or OFF (if there is no operation, the state is
“Unknown”). To select an item to be tested,
users can press ↑ and ↓ . Press ← and → 1. Carbon canister control valve
to control the current switching value, ← to 2. Idle speed control
turn it on and → to turn it off. 3. Stepless fan control
4. Throttle opening control
To give up the right of control of currently
selected item, just press ↑ and ↓ to select
other items to be tested or press [ESC] to exit
the current page.

Press [↑] to move up

Press [↓] to move down
Press [OK] to continue

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Take the setup of the first carbon canister This operation should be carried out by
control valve for example, the setup interface qualified service personnel, or else the
is shown in the figure below. engine can not be started.

The operation of fuel emptying control is as

Component action test follows:

1. Enter into TI Engine Management

System;

Engine Management System

Please enter the valve: 0
Range: 0-100
1. Read computer version

2. Read DTC

3. Clear DTC

4. Read data status

5. Optional data stream display

6. Action test for components

7. Fuel emptying control

Press [←] to back

Press [OK] to set
Press [Esc] to cancel

The first line in above information bar is the Press [↑] to move up

value entered by the user, and the second Press [↓] to move down

line is the value range. The entered value Press [OK] to enter the submenu
shouldn’t exceed the specified range, or else
the operation will fail.

Instructions: use “Component Action 2. Select “Fuel emptying control” and press
Test” with caution. Non-professional OK.
technicians or professional service man
Engine Management System
are not allowed to use this function, as
improper operation may damage the
engine system.
7.5 Description of Fuel Emptying Control

Prompt: Warning:

Please note that improper operation may cause

a) This operation is only for the models engine cylinder submerged
equipped with TI power system.

b) After replacing the fuel pump and

other components of the fuel supply
system or re-fueling after the fuel is
used up naturally, it is required to use
the diagnostic tester to control the fuel
emptying. Without this operation, it may Press [OK] to continue
cause startup failures, or need multiple Press [ESC] to exit
starts to start the car.

Notice:

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3. Press OK to enter into the fuel emptying Fuel Emptying Control

control interface.

Fuel Emptying Control

Fuel emptying control: OFF

Please enter the time:

[Note] The unit is second (s), and allows up to two

digits

Press [ESC] to exit

Press [←] to clear input

Press [OK] to continue

Press [ESC] to exit 7. Press ESC to exit, and check if the start
is normal.

4. Type the control time. Notice:

Prompt: If the car can’t be started after this

operation, please carry out fault diagnosis.
After replacing the fuel pump, it usually takes Do not repeat this operation.
10s~20s to empty the fuel.

5. Press OK to execute.

Fuel Emptying Control

Fuel emptying control: ON

Remaining time: 2s

Press [ESC] to exit

6. After executing, the prompt is as follow.

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8. Appendix
8.1 Regular Maintenance Procedures of EFI System

Note:

• The rules for maintenance are applicable for family cars;

• Interval of vehicle maintenance depends on the reading on the odometer or the time interval,
whichever comes earlier.

• The rules for maintenance must be strictly complied with, which are developed based on
normal use of vehicle as per design.

Mileage 10 15 20 25 30 35 40 45 50 55 60
Item
x1000km 12 18 24 30 36 42 48 54 60 66 72

Months I I I

Spark Plug I R I R I R

Ignition Timing I I I

Engine Idling Speed I I I

Fuel Tank I

Fuel Filter R R

Fuel Injector C* C* C*

Oil filter R R R R R R

Air Filter I R I R I R

Electronic throttle body C C C C C C

Emission Check I I I I I I

Check by Diagnostic Tool I I I

Oxygen Sensor Check I I I I I I

Three-way Catalyst Check I I I I I I

R-Replace

C-Clean

I - Inspect (Replace the spare parts when find out failure in inspection.)

C*- The maintenance of fuel injector had better clean by a special tool --- fuel injector cleaner.

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8.2 DTC List

TB10 DTC List

No. DTC Fault

1 P0010 Open circuit of camshaft regulating valve control circuit

2 P0016 Intake phase deviation is large

3 P0030 Open circuit of front oxygen heating control circuit

4 P0031 Voltage of front oxygen heating control circuit is too low

5 P0032 Voltage of front oxygen heating control circuit is too high

6 P0033 Open circuit of supercharging bypass valve control circuit

7 P0034 Voltage of supercharging bypass valve control circuit is too low

8 P0035 Voltage of supercharging bypass valve control circuit is too high

9 P0036 Open circuit of rear oxygen heating control circuit

10 P0037 Voltage of rear oxygen heating control circuit is too low

11 P0038 Voltage of rear oxygen heating control circuit is too high

12 P0089 Control circuit malfunction of fuel pressure regulating valve

13 P0097 Voltage of supercharged air temperature sensor circuit is too low

14 P0098 Voltage of supercharged air temperature sensor circuit is too high

15 P0107 Voltage of intake air pressure sensor circuit is too low

16 P0108 Voltage of intake air pressure sensor circuit is too high

17 P0112 Voltage of intake air temperature sensor circuit is too low

18 P0113 Voltage of intake air temperature sensor circuit is too high

19 P0117 Voltage of coolant temperature sensor circuit is too low

20 P0118 Voltage of coolant temperature sensor circuit is too high

21 P0121 Throttle position sensor unreasonable

22 P0122 Voltage of throttle position sensor line A is too low

23 P0123 Voltage of throttle position sensor line A is too high

24 P0131 Voltage of front oxygen sensor circuit is too low

25 P0132 Voltage of front oxygen sensor circuit is too high

26 P0134 Open circuit of front oxygen sensor circuit

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27 P0137 Voltage of rear oxygen sensor circuit is too low

28 P0138 Voltage of rear oxygen sensor circuit is too high

29 P0140 Open circuit of rear oxygen sensor circuit

30 P0192 Voltage of fuel pressure sensor circuit is too low

31 P0193 Voltage of fuel pressure sensor circuit is too high

32 P0201 Open circuit of 1# fuel injector control circuit

33 P0202 Open circuit of 2# fuel injector control circuit

34 P0203 Open circuit of 3# fuel injector control circuit

35 P0204 Open circuit of 4# fuel injector control circuit

36 P0221 Throttle position sensor signal unreasonable

37 P0222 Voltage of throttle position sensor line B is too low

38 P0223 Voltage of throttle position sensor line B is too high

39 P0226 Pedal position sensor signal unreasonable

40 P0227 Voltage of pedal position sensor line 1 is too low

41 P0228 Voltage of pedal position sensor line 1 is too high

42 P0236 Supercharging pressure sensor signal unreasonable

43 P0237 Voltage of supercharging pressure sensor circuit is too low

44 P0238 Voltage of supercharging pressure sensor circuit is too high

45 P0261 Voltage of low side of 1# fuel injector is too low

46 P0262 Voltage of low side of 1# fuel injector is too high

47 P0263 Short circuit between low side and high side of 1# fuel injector

48 P0264 Voltage of low side of 2# fuel injector is too low

49 P0265 Voltage of low side of 2# fuel injector is too high

50 P0266 Short circuit between low side and high side of 2# fuel injector

51 P0267 Voltage of low side of 3# fuel injector is too low

52 P0268 Voltage of low side of 3# fuel injector is too high

53 P0269 Short circuit between low side and high side of 3# fuel injector

54 P0270 Voltage of low side of 4# fuel injector is too low

55 P0271 Voltage of low side of 4# fuel injector is too high

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56 P0272 Short circuit between low side and high side of 4# fuel injector

57 P0300 Single cylinder or multi-cylinder misfire

58 P0301 1# cylinder misfire

59 P0302 2# cylinder misfire

60 P0303 3# cylinder misfire

61 P0304 4# cylinder misfire

62 P0335 Crankshaft position sensor signal malfunction

63 P0336 Crankshaft position sensor signal unreasonable

64 P0340 Camshaft position sensor signal malfunction

65 P0341 Camshaft position sensor signal unreasonable

66 P0351 Open circuit of 1# ignition coil control circuit

67 P0352 Open circuit of 2# ignition coil control circuit

68 P0353 Open circuit of 3# ignition coil control circuit

69 P0354 Open circuit of 4# ignition coil control circuit

70 P0444 Open circuit of carbon canister electromagnetic valve control circuit

71 P0458 Voltage of carbon canister electromagnetic valve control circuit is too low

72 P0459 Voltage of carbon canister electromagnetic valve control circuit is too high

73 P0476 Open circuit of supercharging pressure limit valve control circuit

74 P0477 Voltage of supercharging pressure limit valve control circuit is too low

75 P0478 Voltage of supercharging pressure limit valve control circuit is too high

76 P0480 Open circuit of stepless fan control circuit

77 P0562 System voltage is too low

78 P0563 System voltage is too high

79 P0620 AC generator load malfunction

80 P0627 Open circuit of fuel pump control circuit

81 P0628 Voltage of fuel pump control circuit is too low

82 P0629 Voltage of fuel pump control circuit is too high

83 P0633 ECM and theft protection system authentication fails

84 P0645 Open circuit of A/C permission control circuit

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85 P0646 Voltage of A/C permission control circuit is too low

86 P0647 Voltage of A/C permission control circuit is too high

87 P0691 Voltage of stepless fan control circuit is too low

88 P0692 Voltage of stepless fan control circuit is too high

89 P1601 Stepless fan motor stalled or short circuit

90 P1602 Stepless fan overtemperature protection or electronic errors

91 P1611 ECM internal failure 1

92 P1612 ECM internal failure 2

93 P1613 ECM internal failure 3

94 P1614 ECM internal failure 4

95 P1615 ECM internal failure 5

96 P1616 ECM internal failure 6

97 P1617 ECM internal failure 7

98 P1618 ECM internal failure 8

99 P1621 Intercooler system malfunction

100 P2088 Voltage of camshaft regulating valve control circuit is too low

101 P2089 Voltage of camshaft regulating valve control circuit is too high

102 P2100 Open circuit of throttle motor control circuit

103 P2102 Voltage of throttle motor control circuit is too low

104 P2103 Voltage of throttle motor control circuit is too high

105 P2118 Throttle regulating malfunction or open circuit of control line

106 P2119 Mechanical failure of the throttle body

107 P2121 Pedal position sensor signal unreasonable

108 P2122 Voltage of pedal position sensor line 2 is too low

109 P2123 Voltage of pedal position sensor line 2 is too high

110 P2147 Voltage of high side of 1# fuel injector is too low

111 P2148 Voltage of high side of 1# fuel injector is too high

112 P2150 Voltage of high side of 2# fuel injector is too low

113 P2151 Voltage of high side of 2# fuel injector is too high

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114 P2184 Voltage of cooling water temperature sensor circuit at the radiator outlet is too low

115 P2185 Voltage of cooling water temperature sensor circuit at the radiator outlet is too high

116 P2227 Atmospheric pressure sensor signal unreasonable

117 P2228 Voltage of atmospheric pressure sensor circuit is too low

118 P2229 Voltage of atmospheric pressure sensor circuit is too high

119 P2300 Voltage of 1# ignition coil control circuit is too low

120 P2301 Voltage of 1# ignition coil control circuit is too high

121 P2303 Voltage of 2# ignition coil control circuit is too low

122 P2304 Voltage of 2# ignition coil control circuit is too high

123 P2306 Voltage of 3# ignition coil control circuit is too low

124 P2307 Voltage of 3# ignition coil control circuit is too high

125 P2309 Voltage of 4# ignition coil control circuit is too low

126 P2310 Voltage of 4# ignition coil control circuit is too high

127 P2600 Open circuit of cooling pump control circuit

128 P2602 Voltage of cooling pump control circuit is too low

129 P2603 Voltage of cooling pump control circuit is too high

130 U0121 Communication failure between ECM and ABS

131 U0164 Communication failure between ECM and A/C controller

132 U0168 Communication failure between ECM and keyless system

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8.3

318
Electrical Diagram

Air blower

Window control system 50A

Rear defroster relay
Front air blower relay Compressor relay

Small lamp
Ignition switch 50A
Diagram of engine room fuse and relay box

2# ignition switch
Lighting, CAN module Compressor
Power seat Auxiliary power

Main fuse 125A

Right dipped headlight
refer to the diagrams to check failures and service.

Daytime running light

Definition of Distributor Box Fuses and Relays

Left dipped headlight

Reserved

Electric fan
Front fog lamp
Electric fan 50A
Left high beam
BYD S6, S6A, S6K Service Manual

Right high beam

Front fog lamp relay

Horn Warning signal lamp Daytime running light relay
Turn lamp Brake lamp
For different models, please refer to the corresponding wiring harness diagrams; please strictly
 BYD S6, S6A, S6K Service Manual

Relay specification and purpose of engine room fuse and relay box:

Position Definition Specification Position Definition Specification

K1-1 Front air blower relay 30A K1-4 Front fog lamp relay 20A

K1-2 Compressor relay 20A K1-5 Daytime running light relay 20A

K1-3 Rear defroster relay 30A

Fuse specification and purpose of engine room fuse and relay box:

No. Specification Purpose No. Specification Purpose

F1/1 10A Right high beam F1/14 20A Horn, brake lamp

F1/2 10A Left high beam F1/15 40A Rear defroster

F1/3 10A Left dipped headlight F1/16 40A Door lock, MICU constant power

F1/4 10A Right dipped headlight F1/17 25A ABS

F1/5 10A 2# ignition switch F1/18 40A EMS

F1/6 15A Small lamp F1/19 40A ABS

F1/7 7.5A MCU F1/20 40A Power seat

F1/8 20A Reserved F1/21 40A Air blower

F1/9 15A EMS F1/22-1 125A Main fuse

F1/10 20A Front fog lamp F1/22-2 50A Electric fan

F1/11 15A Daytime running light F1/23-1 50A Door & window motor

F1/12 7.5A Compressor F1/23-2 50A Ignition switch

F1/13 15A Turn lamp

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 Starter relay
Flash relay

Windshield Starter Reserved fuse

wiper system
BYD S6, S6A, S6K Service Manual

Cigar lighter relay Motor control Assistant driver’s

module power seat
Relay control Interior rearview Reserved fuse

Fuel pump relay

module mirror direction
display
Reserved fuse Rear left window Driver’s power seat
control
Exterior rearview Front right window Seat heating
mirror heating control

AT relay
Diagram of instrument panel fuse and relay box

Washer motor Rear right window Rear fog lamp

control

Power window relay

Reserved Front left window Cigar lighter
control
Engine ECU Sunroof motor Acoustics system

EFI main relay II

EFI main relay II Multi-channel
integrated
controller
Fuel pump motor Steering lock Roof lamp

EFI main relay I

EFI main relay I Oxygen sensor Door lock motor

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Relay specification and purpose of instrument panel fuse and relay box:

Position Definition Specification Position Definition Specification

K2-1 EFI main relay II 30A K2-5 Power window relay 30A

K2-2 A/T relay 30A K2-6 Fuel pump relay 20A

K2-3 Cigar lighter relay 20A K2-7 Starter relay 20A

K2-4 EFI main relay I 30A K2-8 Flash relay

Fuse specification and purpose of instrument panel fuse and relay box:

Position Definition Position Definition Position Definition

Door stopper
F2/1 F2/12 Oxygen sensor (7.5A) F2/23 EFI main relay I (15A)
(20A)
Door courtesy, Steering lock/unlock
F2/2 F2/13 F2/24 Oil pump motor (15A)
roof lamp (7.5A) (7.5A)
Control module
F2/3 constant power F2/14 IG2 power (10A) F2/25 EFI main relay II (15A)
(10A)
Acoustics system
F2/4 constant power F2/15 Electric sunroof (20A) F2/26 EMS (15A)
(15A)
Cigar lighter Front left window
F2/5 F2/16 F2/27 Reserved (10A)
(15A) motor (20A)
Rear fog lamp Rear right window
F2/6 F2/17 F2/28 Washer motor (15A)
(7.5A) motor (20A)
Seat heating Front right window Exterior rearview mirror
F2/7 F2/18 F2/29
(20A) motor (20A) defroster (7.5A)
Front left power Rear left window
F2/8 F2/19 F2/30 Reserved fuse (15A)
seat (25A) motor (20A)
Reserved fuse 2-position switch mode
F2/9 F2/20 Auxiliary power (7.5A) F2/31
(25A) power supply (7.5A)
Front right power Motor control module
F2/10 F2/21 F2/32 SRS (15A)
seat (25A) (15A)
Reserved fuse Front windshield wiper
F2/11 F2/22 Starter (20A) F2/33
(20A) power (30A)

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Section 4 BYD 483QA M7 Engine Management System

Preface
With the development of national economy, the car ownership is increasing, and the environ-
mental regulations are constantly stricter. From July 1, 2000, the Euro-I emission regulations had
been implemented for newly produced cars. Recently, the Ministry of Environmental Protection
informed that the cars and light vehicles with carburetor engines wouldn’t be allowed for licens-
ing from September 1, 2001. At the same time, the Euro-I emission regulations would also be
implemented for the trucks lower than 3.5t. In fact, many automobile manufacturers develop new
products basing on Euro-II instead of Euro-I. The successful organization of 2008 Beijing Olympic
Games had further promoted China’s automobile emission control.

Since the combination of closed-loop control of petrol rationing and three-way catalytic converter
may reduce emission of toxic substances by more than 92%, replacing the carburetor with elec-
tronically controlled gasoline injection technology has become an irreversible trend. This suggests
that, the carburetor engine era has ended in the Chinese automotive industry, and electronically
controlled gasoline injection engine era had begun.

As the No.1 supplier of auto engine electronic control fuel injection system in China, United Auto-
motive Electronic Systems Co., Ltd. started to supply MOTRONIC series electronic fuel injection
system introduced from Germany BOSCH in china from 1996. As a trademark, MOTRONIC does
not have specific meaning, but MOTRONIC system indeed has certain unique technology char-
acteristics, that is the two systems of fuel quantitative electronic control system and ignition timing
electronic control system are integrated to share a set of sensors, electronic control unit and pow-
er device. MOTRONIC systems all have the ignition timing electronic control function, obviously
improving the engine performance.

Like other electronic control fuel injection system, MOTRONIC system on the one hand can de-
crease the vehicle emission largely; on the other hand, it also presents difficulties to the repairer
who is only familiar with the engines equipped with a traditional carburetor. There are no familiar
mechanical components in electronic control fuel injection engine, which is replaced with a va-
riety of electronic components. Formerly, the repairer even driver can adjust the carburetor or
distributor; however, now with the data stored in the computer chips, the common repairer can
not eliminate malfunction through using electronic instrument to modify data. When the electronic
components have malfunction, it can not be identified from the external without using instruments
for test. So when repairing the electronic control fuel injection engine, the repairer often feels at
limit. In light of this realistic condition, we write this repair manual to offer help in two sides: help
the engineers of engine factory or whole vehicle factory to know more about the engine electronic
control system; and help the repairers in repairing the electronic control fuel injection engine.

The manual firstly introduces the composition and working principle of electronic control fuel injec-
tion system. And then introduce the structure and performance of every part in detail.

Generally speaking, fault diagnosis instrument, which can read the fault information record stored
in the ECU, is an essential tool in the process of repairing the electronic control fuel injection sys-
tem. To help reader understand real meaning of every kind of fault codes, this manual lists all fault
conditions for ECU to set a fault code. However, many faults can not be confirmed directly ac-
cording to fault information record, and it may sometimes take a series of analysis to find out the
real cause of a fault. So, this manual uses many pages to describe how to find out the real fault
according to fault information record.

Electronic control unit’s existence itself brings up many new fault causes of engines. In other
word, the same kind of engine fault may be caused by mechanical reason, also may be by elec-
tronic reason. And use of fault diagnosis instrument may not always be able to pinpoint the fault.
So, this manual combines engine symptom with the electronic control system to locate fault.

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1. Maintenance Notice of Electronic Fuel Injection System

1.1 General Maintenance Precautions

1) Only allow using digital multimeter to check the electronic fuel injection system.

2) Only use genuine product parts when repairing, or it can not ensure the electronic fuel injec-
tion system to work normally.

3) In the maintenance process, can only use unleaded gasoline.

4) Please abide by normative maintenance diagnosis process to do maintenance working.

5) In the maintenance process, never disassemble parts of electronic fuel injection system.

6) In the maintenance process, take care when holding electronic component (such as elec-
tronic control unit, sensor) to avoid dropping them on the ground.

7) Build up the environmental protection consciousness, properly deal with the castoff produced
in the maintenance.
1.2 Precautions in Maintenance Process

1) Do not disassemble any parts of electronic fuel injection system or its connector from its in-
stallation position randomly to avoid accidental damaging or entering of water, oil pollution,
which may influence the normal working of electronic fuel injection system.

2) When disconnecting or connecting the connector, always turn the ignition switch to OFF po-
sition, or it can damage electric component.

3) When doing the fault’s heat states condition simulation and other maintenance working
which can make the temperature rise, always keep the temperature of electronic control unit
below 80°C.

4) The supply pressure of electronic fuel injection system is high (about 350kPa), so all fuel
pipes adopt the high pressure fuel pipes. Even if the engine is not running, there is also high
fuel pressure in the fuel circuit. Do not disassemble the fuel pipes in maintenance process
unless necessary. When it is needed to maintain fuel pipes, you should do pressure relief
treatment to fuel system before disassembling the fuel pipes as following: start the engine
and make it running idle, connect the diagnosis instrument, enter “Actuator Test” and shut off
the fuel pump, till the engine going out by itself. The disassembly of fuel pipes and replace-
ment of fuel filter should be done at the draughty place by qualified repairer.

5) When getting down the electric fuel pump from fuel tank, do not electrify the fuel pump to
avoid generating electric spark and causing the fire.

6) It is not allowed to test fuel pump under dry state or in the water, or it may decrease the ser-
vice life, in addition the anode and cathode of fuel pump can not be connected reversely.

7) When checking the ignition system, do sparking test only when necessary, and time duration
shall be as short as possible. Do not open the throttle when testing, or it may cause a lot of
unburnt gasoline entering into exhaust pipe and damage the three way catalyst.

8) Because the idle regulation is accomplished completely by the electronic fuel injection sys-
tem, it does not need manual regulation. The throttle stop screw of throttle body has been
regulated when leaving factory, the user is not allowed to change its position.

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9) When connecting the battery, the anode and cathode of battery can not be connected re-
versely or electronic component may be damaged. The system adopts cathode ground.

10) When engine running, do not disassemble battery cable.

11) Before welding on the vehicle, cable of battery anode, cathode and electronic control unit
shall be removed.

12) Do not pierce insulation layers of the cable to test the input and output electronic signal of
parts.
1.3 Maintenance Tool Summary

Tool name:

Electronic fuel injection system fault diag-

nosis instrument

Function:

Read/clear fault code of electronic fuel injec-

tion system, observe data stream, parts ac-
tion test and so on.

Tool name:

Electronic fuel injection system adapter

Function:

Check every stitch’s electrical signal of elec-

tronic control unit, check the circuital condi-
tion and so on.

Tool name:

Ignition timing light

Function:

Check the ignition timing of engine and so on.

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Tool name:

Digital multimeter

Function:

Check characteristic parameters, such as the

voltage, current, resistance, in the electronic
fuel injection system.

Tool name:

Vacuum meter

Function:

Check the pressure condition in the intake

manifold.

Tool name:

Cylinder pressure gauge

Function:

Check the cylinder pressure condition of ev-

ery cylinder.

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Tool name:

Fuel pressure gauge

Function:

Check the pressure condition of fuel system,

determine the working condition of fuel pump
and fuel pressure regulator in the fuel system.

Tool name:

Exhaust analyzer

Function:

Check the exhaust emission condition of ve-

hicle, help to judge the fault of electronic fuel
injection system.

Tool name:

Injector clean analyzer

Function:

Can do the clean analyzer working to injector.

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1.4 Abbreviations in the Manual

DG Speed sensor
DKG Throttle position sensor
DLA Idle regulator/step motor
DR Fuel pressure regulator
DS-S-TF Intake pressure temperature sensor
ECU Electronic control unit (computer)
EKP Fuel pump
EMS Engine management system
EWD Idle regulator/rotating pilot valve
EV Fuel injector
LSH Heating type oxygen sensor
KS Knock sensor
KSZ Fuel distributor assembly
KVS Fuel distributor
PG Phase sensor
ROV Ignition system with distributor
RUV Ignition system without distributor
TEE Fuel pump bracket assembly
TEV Canister control valve
TF-W Coolant temperature sensor
ZSK Ignition coil

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2. M7 System Introduction
2.1 System Basic Principle

2.1.1 System summary: M7-Motronic engine management system

Engine management system, usually consisted of sensor, microprocessor (ECU) and actuator,
controls the intake air quantity, fuel injection quantity and ignition advance angle. Basic structure
is shown in the figure 2.1.

Diagnosis Diagnos is
Sensor ECU Actuator

Engine

Figure 2-1 Engine electronic control system composition

In engine electronic control system, sensor acts as input part to measure every kind of physics
signals (temperature, pressure etc.) and then convert it into corresponding electrical signal; ECU
receives the input signal of sensor, makes calculation according to setting program and generate
corresponding control signal and output to power driving circuit; the power driving circuit makes
the engine running according to vested control strategy through driving every actuator to execute
different actions; fault diagnosis system of ECU can monitor every parts in system or control func-
tion, and, once any fault is detected and affirmed, save the fault code and activate “limp home”
function. When ECU detects that the fault is eliminated, the normal value will resume in use.

The most important feature of M7 engine electronic control management system is torque-based
control strategy. The main purpose of torque-based control strategy is to interlink different control
targets together. M7 engine electronic control system structure is shown in figure 2.2.

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Electronic fuel pump and

bracket assembly

Figure 2-2 M7 engine electronic control system structure diagram

Basic components of M7 engine electronic control system is:

Electronic control unit (ECU) Idle regulator

Air mass flowmeter (depending on models) Fuel injector
Intake pressure/temperature sensor Electronic fuel pump
Coolant temperature sensor Fuel pressure regulator
Throttle position sensor Fuel pump bracket
Phase sensor Fuel distributor
Speed sensor Canister control valve
Knock sensor Ignition coil
Oxygen sensor

M7-Motronic system is an electronic controlled gasoline engine control system. It supplies many
control features about operator and vehicle or equipment, and combines open loop and closed
loop (feedback) control together, providing a variety types of control signals for engine running.
The main functions of system are:

1) Basic management of engine using physical models

• System structure based on torque

• Decide cylinder load quantity by intake pressure sensor/air mass sensor

• Improve the mixture gas control function under both static and dynamic status

• λ closed loop control

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• Sequential Electronic Fuel Injection

• Ignition timing, including sequential cylinder knock control

• Emission control function

• Catalyst heating

• Canister control

• Idle control

• Limp home

• Progress speed sensing through increment system

2) Additional function

• Anti-thief function

• Connection of torque and external function (such as transmission mechanism or vehicle dy-
namic control)

• Control of several kinds of engine parts

• Supply the interface matching EOL-programming tool and repair tool

3) On-line diagnosis OBD II

• Complete a series of OBD II functions

• Management system used as diagnosis function

2.1.2 Torque structure: M7 system based on torque control

In the M7 engine management system, all interior requirements and exterior requirements of
engine are defined with the engine’s torque or efficiency requirement, as shown in figure 2.3. Dif-
ferent requirements of the engine are converted into control variables of torque or efficiency, and
then these variables are processed in center torque demand coordinator module firstly. M7 sys-
tem can arrange these mutual conflicting requirements according to priority order and execute the
most important requirement. It obtains engine control parameters such as fuel injection time, igni-
tion timing through torque converter module. In this process, the control variable’s execution has
no influence on other variables, which is the advantage offered by torque-based control system.

As for matching the engine, the control system based on torque only depends on engine data
when matching engine characteristic curve and pulse spectra as it has variable independence,
eliminating interference with other performance functions and variables. It avoids repeated de-
marcating, simplifies the matching process and reduces the matching cost.

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Figure 2-3 M7 system structure based on torque

Compared with the conventional M series engine electronic fuel injection management system,
the main characteristics of M7 system are:

• New engine function structure which treats the torque as variable, allowing easiest compat-
ibility with other systems and strong expandability;

• New modular software structure and hardware structure, powerful transplantable capability;

• Basic engine characteristic graphs based on model, which are independent and simplify the
calibration process;

• Phase sensor, sequence fuel injection, which is helpful to improve emission;

• Anti-thief function integrated in the system ;

• Improve the drive performance through coordinating every kind of torque requirements;

• 16 bits CPU, 24 MHZ clock frequency, 512k cache;

• The system makes room for requirements in the future, for example: emission regulation,
OBD II, electronic throttle, etc.
2.2 Control signal: M7 system input/output signal

In M7 system, the main sensor input signals of ECU includes:

• Intake pressure signal

• Intake temperature signal

• Throttle angle signal

• Coolant temperature signal

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• Engine speed signal

• Phase signal

• Knock sensor signal

• Oxygen sensor signal

• Speed signal

• A/C pressure signal

After the signals above enter into ECU, they will be processed to generate the needed actuator
control signals. These signals are amplified in the output driving circuit and transferred into every
corresponding actuator. These control signals include:

• Idle regulator opening

• Fuel injection timing and fuel injection duration

• Fuel pump relay

• Canister control valve opening

• Ignition coil close angle and ignition advance angle

• A/C compressor relay

• Cooling fan relay

2.3 System function introduction

2.3.1 Starting control

In the starting process, special calculation method is used to control the intake quantity, fuel in-
jecting and ignition timing. In the beginning stage of the process, the air in the intake manifold is
static; the interior pressure of intake manifold is displayed as the atmospheric pressure around.
When closing the throttle, the idle regulator will be appointed with a fixed parameter which is de-
cided according to starting temperature.

In the similar process, specific “fuel injection timing” is appointed as primary injection pulse.

The fuel injection quantity is vary with the engine temperature to facilitate the fuel film forming in
the intake manifold and on the cylinder wall, therefore, before the engine speed reaches certain
speed, mixture of gas and air shall be enriched.

Once the engine starts to run, system immediately begins to decrease the starting enriching till
completely canceling the starting enriching when the starting condition is over (600…700min-1).

The ignition angle is adjusted continuously under starting condition along with engine tempera-
ture, intake temperature and engine speed.

2.3.2 Heating control of warm-up engine and three-way catalyst

After the engine is starting at low temperature, the cylinder intake quantity, fuel injection and elec-
tronic ignition are all adjusted to compensate the higher torque requirement of engine; the pro-
cess is continued until the engine reaches proper temperature threshold.

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In this stage, the most important is quick heating of three-way catalyst, because quickly transit-
ing to working status of three-way catalyst can decrease the emission greatly. Under this working
condition, the ignition advance angle is delayed moderately so that exhaust gas can be used to
heat up three-way catalyst.

2.3.3 Accelerate/decelerate and inverted towed fuel cut-off control

Part of the fuel injecting into intake manifold can not arrive at the cylinder in time to joint the fol-
lowing burning process. Contrarily, it will form a layer of fuel film on the intake manifold wall.
When the load improves and fuel injection duration prolongs, the fuel quantity in the fuel film can
increase rapidly.

When the throttle opening is increasing, part of the injection fuel is absorbed by fuel film. So sup-
plement fuel quantity must be injected correspondingly to compensate it and prevent the mixture
gas get less dense when accelerating. Once the load factor is decreasing, the additional fuel in-
cluded in fuel film on the intake manifold wall will be released again, as a result, in the decelerat-
ing process, fuel injection duration must be decreased correspondingly.

Inverted haul or towed condition is referred to the situation that the power supplied by engine on
flywheel is negative. Under this situation, engine friction and pumping loss can be used to make
the vehicle decelerate. When the engine is in the condition of inverted haul or towed, the injection
fuel is cut off to decrease the fuel consumption and the exhaust emission, and, the more impor-
tant, to protect the three-way catalyst.

Once when the speed is decreasing to a certain speed where fuel supply is recovered over the
idle speed, the fuel injection system will resume supply fuel. In fact, there is a range of recovery
speed in ECU program. Recovery speed varies with parameters such as engine temperature,
engine speed dynamic change, and prevents the speed decreasing to stated lowest threshold
through calculating.

Once the fuel injection system is supplying fuel anew, system begins to use primary fuel injection
pulse to supply supplement fuel, and build the fuel film again on the intake manifold wall. After
recovering fuel injection, the control system based on torque makes the engine torque increase
slowly and stably.

2.3.4 Idle control

In idle speed, the engine does not supply torque to the flywheel. To ensure the engine to run sta-
bly in the idle speed as low as possible, the closed loop idle control system must keep the bal-
ance between the torque generated and engine “power consumption”. It needs to generate cer-
tain power in idle speed to satisfy the load requirement of different aspects, including crankshaft
and valve mechanism from engine and auxiliary components, such as the interior friction of water
pump.

Torque-based control strategy of M7 system uses closed loop idle control to determine the
needed engine output torque to keep the required idle speed under every working condition. The
output torque is increased as the engine speed decreases, and decreased as the engine speed
increases. The system requests larger torque to answer new “interference factors”, such as the
opening and closing of A/C compressor or shifting gear of AT. When the engine temperature is
low, it also needs to increase the torque to compensate larger interior friction loss and/or keep
higher idle speed. The total of all these output torque demands is passed to torque coordinator,
which processes such demands to obtain the corresponding density, mixture component and igni-
tion timing.

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2.3.5 λ close ring control

Post-exhausting treatment in the three-way catalyst is an effective method to decrease the con-
centration of harmful substance in exhaust gas. The three-way catalyst can decrease the HC,
CO, NOx by 98% or more, converting them into H2O, CO2 and N2. But it can reach the high ef-
ficiency only when the engine excess air ratio λ falls in a narrow range around 1, and the aim of
λ closed loop control is to ensure the mixture concentration is in this range.

λ close loop control can work only when equipping oxygen sensor. The oxygen sensor on the
side of three-way catalyst inspects the oxygen content in exhaust gas, lean mixture (λ>1) gen-
erates the sensor voltage about 100mV; rich mixture (λ<1) generates the sensor voltage about
900mV. When the λ=1, the sensor voltage has a jumping. λ closed loop control answers the
input signal (λ>1=lean mixture, λ>1=rich mixture) and then modifies the control variable, and
generates the correction factor to act as multiplier to correct the fuel injection duration.

2.3.6 Evaporative emission control

Because of the exterior radiation heat and return fuel heat transfer, the fuel in the tank is heated,
and form fuel steam. Because limited by evaporation emission code, the steam which contains a
lot of HC is not allowed to exhaust into air directly. The fuel steam in the system is collected in the
carbon canister though canal, and entered into engine and jointed in burning processes by blow-
ing and washing at the proper time. The airflow which is used to blow and wash the gas is real-
ized through control valve of ECU controls canister. This control only works when λ closed loop
control system works in closed loop status.

2.3.7 Knock control

System detects the characteristic vibration when the knock is happening through the knock sen-
sors installed on the proper positions of engine, translates the vibration into electronic signals,
which is transferred into ECU for processing. ECU detect whether the knock happens in the every
burning circle of every cylinder using the special arithmetic. Once the knock is detected, it will trig-
ger knock closed loop control. After the knock danger is eliminated, the ignition advance angle of
influenced cylinders is reset to scheduled value gradually.

The threshold valve has good adaptability to different working condition and different grade of
fuel.
2.4 System fault diagnosis function introduction

2.4.1 Fault information record

Electronic control unit constantly detects the sensor, actuator, correlative circuit, fault indicator
and battery voltage, even electronic control unit itself, and make reliability test to sensor output
signal, actuator driving signal and interior signals (such as λ closed loop control, coolant tem-
perature, knock control, idle speed control and battery voltage control, etc.). Once it finds that any
link appears fault, or some signal value is not reliable, the electronic control unit immediately sets
the fault information record in fault memory of RAM. The fault information records are stored in
the form of fault code and displayed in order of appearance.

The fault can be divided into “random failure” and “stable failure” (for example, faults caused by
transient open harness circuit or poor connector contact) according to the frequency of its appear-
ance.

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Figure 2-4 Electronic fuel injection system fault diagnosis principle diagram

2.4.2 Three grades of fault

CLASS 5

Action when setting diagnosis fault code

• Once the fault appears, corresponding fault code, as well as correlative fault information is
saved in fault code memory.

• If the fault appears in 3 continuous driving cycles, the fault is affirmed, but ECU does not turn
on fault indicator.

The condition to clear fault indicator/fault code

• After the fault is affirmed, it is deemed to have been repaired if the engine runs for 3 continu-
ous driving cycles without fault.

• For an affirmed fault, if the engine runs for 40 continuous preheating cycles without fault after
the fault is repaired, the fault code is cleared.

• For a random failure, if the engine runs for 40 continuous preheating cycles without fault, the
fault code is cleared.

CLASS 31

Action when setting diagnosis fault code

• Once the fault appears, corresponding fault code, as well as correlative fault information is
saved in fault code memory.

• If the fault appears in 3 continuous driving cycles, the fault is affirmed, but ECU does not turn
on fault indicator.

The condition to clear fault indicator/fault code

• After the fault indicator turns on, the engine runs for 1 second without detecting fault, the
fault is deemed to have been repaired. the fault indicator turn soff..

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• For an affirmed fault, after 40 continuous preheating cycle without fault after the fault is re-
paired, the fault code is cleared

• For a random failure, after 20 continuous preheating cycle without fault, the fault code is
cleared.

CLASS 33

Action when setting diagnosis fault code

• Once the fault appears, corresponding fault code, as well as correlative fault information is
saved in fault code memory.

• If the fault last for 2second, the fault is affirmed and ECU doesn’t turn on fault indicator.

The condition to clear fault indicator/fault code

• After the fault is affirmed, if the engine runs for 1 second without detecting fault, the fault is
deemed to have been repaired.

• For an affirmed fault, after 40 continuous preheating cycle without fault after the fault is re-
paired, the fault code is cleared

• For a random failure, after 20 continuous preheating cycle without fault, the fault code is
cleared.

2.4.3 Control strategy of fault indicator

When no fault

• After the ignition switch is turned to ON, the fault indicator turns on and goes out after 4 sec-
onds;

• Start in 4 seconds, the fault indicator turns off after finding the speed signal;

• After K line grounds over 2.5 seconds, the fault indicator flashes at 2Hz.

When having fault

• After the ignition switch is turned to ON, the fault indicator is always on;

• Start, the fault indicator turns off after finding the speed signal; if the fault indicator is defined
to On mode in the fault class, the fault indicator remains on if corresponding confirmation
condition is satisfied;

• After K line grounds over 2.5 seconds, it outputs flashing code (P-CODE value). For exam-
ple: the flashing mode of P0203 is: continuously flash 10 times- intermission- continuously
flash 2 times -intermission- continuously flash 10 times- intermission- continuously flash 3
times.

2.4.4 Four kinds of fault classes

B_mxdfp Max fault, the signal exceeds the upper limit of normal range.

B_mndfp Min fault, the signal exceeds the lower limit of normal signal.

B_sidfp Signal fault, no signal.

B_npdf Unreasonable fault, signal is available but unreasonable.

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2.4.5 Connection of diagnosis instrument

The system adopts “K” line communication agreement and ISO 9141-2 standard diagnosis joint
(see figure 2.5). This standard diagnosis joint is fixed and connected on engine harness. 4#, 7#
and 16# stitches are used to connect with the engine management system (EMS), in which the 4#
stitch is connected with ground line on vehicle, 7# stitch is connected with 71# stitch of ECU, that
is, the “K” line of engine data, and 16# stitch is connected with battery anode.

Figure 2-5 ISO9141-2 standard diagnosis joint

ECU can communicate with external diagnosis instrument through “K” line, and make the
following operations:

(See Using Introduction of M7 Diagnosis Instrument for description of functions and diagnosis in-
strument operations)

1. Engine parameter display

1.1 Engine speed, coolant temperature, throttle opening, ignition advance angle, fuel injection
pulse width, intake pressure, intake temperature, vehicle speed, system voltage, fuel injec-
tion correction, carbon canister scouring rate, idle speed air control, oxygen sensor wave-
form;

1.2. Engine speed objective, engine relative load, environment temperature, ignition closed time,
evaporator temperature, intake flowrate, fuel consumption;

1.3. Throttle position sensor signal voltage, coolant temperature sensor signal voltage, intake
temperature sensor signal voltage, intake pressure sensor signal voltage, knock sensor1#
stitch signal voltage, knock sensor 2# stitch signal voltage.

2. Electronic fuel injection system status display

Anti-thief system status, safety status, program status, cooling system status, stable working
condition status, dynamic working condition status, emission control status, oxygen sensor sta-
tus, idle status, fault indicator status, emergency working condition status, A/C system status, AT/
torque request status.

3. Actuator test function

Fault indicator, fuel pump, A/C relay, fan, ignition, fuel injection (single cylinder fuel cut-off).

4. Milemeter display

Running mileage, running time.

5. Edition information display

Vehicle frame No. (VIN), ECU hardware No., ECU software No.

6. Fault display

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Intake pressure sensor, intake temperature sensor, engine coolant temperature sensor, throttle
position sensor, oxygen sensor, oxygen sensor heating line, air-fuel ratio correction, every cylin-
der injector, fuel pump, knock sensor, engine speed sensor, phase sensor, carbon canister control
valve, cooling fan relay, vehicle speed signal, idle speed, idle regulator, system voltage, ECU, A/C
compressor relay, evaporator temperature sensor, fault indicator.

2.4.6 Reading the fault information through flashing code

Turn on the ignition switch and ground engine data K line (standard diagnosis joint 7#) over 2.5
seconds. If there is fault code in ECU fault memory, flashing code sent out by engine fault indica-
tor is the value of P-CODE. For example, P0203 flashing mode is: continuously flash 10 times-
intermission- continuously flash 2 times -intermission- continuously flash 10 times- intermission-
continuously flash 3 times.
2.5 Explanation Related to Items

System characteristic:

Multi-point sequential injection system;

New engine function structure using the torque as variable, compatible with other systems and
with strong expansibility;

New modular software structure and hardware structure, with strong expansibility;

Adopting cylinder detection signal (phase sensor PG3.8);

Adopting signal panel of 60-2 gear to identify engine speed signal (engine speed sensor DG6);

Adopting step motor air control;

Idle torque closed loop control;

Independent knock control for every cylinder (knock sensor KS-1-K);

Function of heating and protecting catalyst;

Function of limp home;

Flashing code, etc.

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3. Parts Structure, Principle and Fault Analysis of M7 System

3.1 Intake pressure temperature sensor

Diagram and stitch

Intake manifold absolute pressure

and intake temperature sensor

Figure 2-5 Intake pressure temperature sen-

Figure 2-4 Intake pressure temperature sensor
sor circuit diagram

Stitch: 1# grounding;

2# intake temperature signal outputting;

3# connecting with 5V;

4# intake pressure signal outputting.

3.1.1 Installation position

The sensor is made up by two sensors— intake manifold absolute pressure sensor and intake
temperature sensor, and installed on the intake manifold.

3.1.2 Working principle

Intake manifold absolute pressure sensing element is made by a silicon chip, on which a piece
of pressure diaphragm is etched. There are four piezoresistances on the pressure diaphragm,
and they are used as strain elements to form a Wheatstone bridge. A signal processing circuit is
also integrated on the silicon chip. The silicon chip together with a metal shell composes a closed
reference space, in which the air absolute pressure is close to zero. This just forms a Microelec-
tromechanical systems (MEMS). There is a pressure close to zero acting on the activity surface
of silicon chip, and there is the intake manifold absolute pressure acting on the back surface of
it. The thickness of silicon chip is only several microns (μm), so the changing of intake manifold
absolute pressure can make mechanical deformation on the silicon chip, and the four piezoresis-
tances will deform in turn, resulting in resistance change. After processing by the signal process-
ing circuit of silicon chip, it forms the voltage signal in linear relationship with the pressure.

The intake temperature sensing element is a resistance of negative temperature coefficient (NTC),
where the resistance value is changing along with intake temperature. The sensor transmits a
voltage which can express the intake temperature changing to controller.

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Figure 2-6 Profile of intake manifold absolute pressure and intake temperature sensor

1 Seal ring, 2 Stainless steel bush, 3 PC Board,

4 Sensing element, 5 Shell, 6 Pressure bracket,
7 Welding connection, 8 Adhesive connection

3.1.3 Technical characteristic parameter

1) Limit date

Value
Quantity Unit
Min Typical Max
Tolerance power supply voltage 16 V
Tolerance pressure 500 kPa
Tolerance storage temperature -40 +130 °C

2) Characteristic data

Value
Quantity Unit
Min Typical Max
Pressure test range 20 115 kPa
Running temperature -40 125 °C
Running power supply voltage 4.5 5.0 5.5 V
Current when US=5.0V 6.0 9.0 12.5 mA
Load current of output circuit -0.1 0.1 mA
Load resistance to ground or battery 50 kΩ
Response time 0.2 ms
Weight 27 g

3) Transfer function of pressure sensor

UA= (c1 pabs+c0)Us

In formula, UA = signal output voltage (V)

US = power supply voltage (V)

pabs = absolute pressure (kPa)

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c0=-9.4/95

c1=0.85/95 (1/kPa)

The formula above indicates that under the atmospheric pressure, the signal output voltage of
pressure sensor is close to power supply voltage.

If the power supply voltage is 5V, the signal output voltage of pressure sensor is about 4V when
the throttle is widely opening.

4) Limit data of temperature sensor

Storage temperature: -40/+130°C

Carrying capacity of 25°C: 100mW

5) Characteristic data of temperature sensor

Running temperature: -40/+125°C

Rating voltage: running with 1kΩ front end resistance under 5V, or running with test current
≤ 1mA

20°C rating resistance: 2.5 kΩ ± 5%

The temperature and time coefficient in air τ63, v=6m/s: ≤ 45s

3.1.4 Installation precaution

The sensor is designed to be installed on the intake manifold plane of engine. Pressure nozzle and tem-
perature sensor both extrude in the intake manifold, using an O ring to realize seal to the atmosphere.

If it is installed on the vehicle in proper manner (extracting pressure on intake manifold, and pres-
sure nozzle is slant downwards), it can ensure that condensed water will not form on the pressure
sensitive elements.

Drilling and fixing on intake manifold must be done according to drawing supplied on delivery, so
as to ensure long-term seal and also tolerate the erosion of medium.

The reliable contact of joint electric connection is not only affected by joint of main parts, but also
by the material quality and dimensional accuracy of joint on the harness which matches with it.

3.1.5 Fault phenomenon and judging method

• Fault phenomenon: flameout, idle bad etc.

• General fault cause: 1. there is abnormal high voltage or reverse large current in using pro-
cess; 2. the vacuum element is damaged in repairing process.

• Repair precaution: Forbid using high pressure gas to strike the vacuum element; notice to
check whether the output voltage and current of dynamotor are normal when finding the fault
and replacing the sensor.

• Simple measuring method:

Temperature sensor part: (Disassemble the joint) Turn the digital multimeter to ohm range, and
connect the two meter pens respectively to 1#, 2# stitch of sensor. The rating resistance is 2.5kΩ
± 5% at 20°C, and refer to the characteristic curve of following figure for other corresponding re-
sistance value. You can use the simulation method when measuring: blow wind to sensor with
electric hair dryer (do not place the hair dryer too close to sensor) and observe the change of re-

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sistance, which shall drop.

Pressure sensor part: (Connect the joint) Turn the digital multimeter to DC voltage range,
ground the black meter pen grounds, connect the red pen respectively with 3#, 4# stitch. Under
idle status, the 3# stitch should have reference voltage of 5V, 4# stitch voltage is about 1.3V (the
actual value depends on vehicle model); under no-load status, open the throttle valve slowly, the
voltage of 4# stitch changes slowly; open the throttle valve rapidly, the voltage of 4# stitch can
reach to about 4V instantly (the actual value depends on vehicle model), and then decrease to
about 1.5V (the actual value depends on vehicle model).

Figure 2-7 Intake temperature sensor NTC resistance characteristic curve

3.2 Throttle position sensor

Diagram and stitch

Figure 2-8 Throttle position sensor Figure 2-9 Throttle position sensor circuit dia-
gram

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Stitch: For the throttle valve rotating anticlockwise (look at the throttle valve from one side of sen-
sor in the direction of throttle valve shaft) open form:1# grounds; 2# connects to 5V power supply;

For the throttle valve rotating clockwise (look at the throttle valve from one side of sensor in the
direction of throttle valve shaft) open form: 1# connects to 5V power supply;2# grounds;

3# outputs the signal.

3.2.1 Installation position

Install on the throttle body.

3.2.2 Working principle

The sensor is an angle sensor with linearity output, and is made of two arc slip touch resistances
and two slip touch arms. The rotating shaft of slip touch arm connects with throttle shaft on the
same axis. Add 5V power supply voltage US on the two ends of clip touch resistance. When the
throttle is rotating, the slip touch arm rotates along with it, and moves on the slip touch resistance
at the same time, exporting the potential UP of contact as output voltage. So actually it is an angle
potentiometer outputting voltage signal in pro rata relationship with throttle position.

3.2.3 Technical characteristic parameter

(1) Limit data

Quantity Value Unit

Mechanical angle between two end positions ≥ 95 Degree
Electric available angle between two end positions ≤ 86 Degree
Allowable slip arm current ≤ 18 μA
Storage temperature -40/+130 °C
Allowable vibration acceleration ≤ 700 m/s2

(2) Characteristic data

Value
Quantity Unit
Min Typical Max
Total resistance (Stitch 1-2) 1.6 2.0 2.4 kΩ
Slip arm protection resistance
710 1380 Ω
(Slip arm is on zero position, stitch 2-3)
Running temperature -40 130 °C
Power supply voltage 5 V

Voltage ratio of right end position 0.04 0.093

Voltage ratio of left end position 0.873 0.960

Increase ratio of UP/US along with throttle angle 0.00927 1/degree
Weight 22 25 28 g

3.2.4 Installation precaution

Considering about the leakage of the throttle valve shaft seal after long running, it’s suggested
that the throttle valve shaft is equipped at least 30 degrees deflection for vertical direction.

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• The allowable tightening torque of fasten screw: 1.5Nm-2.5Nm.

3.2.5 Fault phenomenon and judgment method

• Fault phenomenon: accelerate bad etc.

• General fault cause: manmade fault.

• Repair precaution: notice the installation position.

• Simple measuring method:

(Disassemble the joint) Turn the digital multimeter to ohm range, and connect the two meter pens
to the 1#, 2# stitch of sensor respectively. The resistance is 2kΩ ± 20% under normal tempera-
ture. Connect the two meter pens respectively to the 1#, 3# stitch, rotate the throttle, the resis-
tance between the two stitches is in linear change along with the throttle opening, but resistance
between 2#, 3# stitches is in the opposite situation.

NOTICE
When observing the resistance value
change, notice whether it has larger
jump.

3.3 Coolant temperature sensor

Diagram and stitch

Figure 2-10 Coolant temperature sensor

Stitch: There are two stitches on the sensor and they can exchange.

3.3.1 Installation position

Install on the water outlet port of engine.

3.3.2 Working principle

The sensor is a thermal resistance of negative temperature coefficient (NTC), where the resis-
tance value decreases when coolant temperature increases, but not in linear relationship. The
NTC thermal resistance is installed on a copper surface (see figure 2-11).

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Figure 2-11 coolant temperature sensor char- Figure 2-12 coolant temperature sensor sec-
acteristic curve tional view

3.3.3 Technical characteristic parameter

(1) Limit data

Quantity Value Unit

Rating voltage Can only use ECU running
Rating resistance in 20°C 2.5 ± 5% kΩ
Running temperature range -30 to +130 °C
Max current through sensor 1 mA
Allowable vibration acceleration 600 m/s2

(2) Characteristic data

Resistance valve(kΩ)
Tempera-
Num-
Temperature tolerance
1°C Temperature tolerance
0°C ture
ber
(°C)
Minimum Maximum Minimum Maximum
1 8.16 10.74 8.62 10.28 -10
2 2.27 2.73 2.37 2.63 +20
3 0.290 0.354 0.299 0.345 +80

3.3.4 Installation precaution

The coolant temperature sensors are installed on the cylinder body, and the copper heat conduc-
tion sleeve shall be inserted into coolant. There is screw thread on the sleeve, and the hexagon
head on sleeve is used to easily screw the coolant temperature sensor into the screw bore on cyl-
inder body. Max. allowable tightening torque is 20N.m.

3.3.5 Fault phenomenon and judgment method

• Fault phenomenon: starting hard etc.

• General fault cause: manmade fault.

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• Simple measuring method:

(Disassemble the joint) Turn the digital multimeter to ohm range, and connect the two meter pens
respectively to the 1#, 3# stitch of sensor. The rating resistance is 2.5kΩ ± 5% at 20°C, and resis-
tance value at other temperature can be measured from the characteristic curve. You can use the
similar method when measuring: dip the operating part of the sensor in boiled water for sufficient
time and observe the change in resistance value. It shall drop to 300Ω-400Ω (depending on boil-
ing point of water).
3.4 Knock sensor

Diagram and stitch

Figure 2-13 Knock sensor without cable Figure 2-14Knock sensor with cable

1. Vibration shock

2. Shell

3. Piezoelectricity ceramic body

4. Contactor

5. Electric joint

Figure 2-15 Knock sensor sectional view

Stitch: 1# ,2#connect to ECU;3# is shielded.

3.4.1 Installation position

3rd cylinder engine is installed in the middle of 2nd cylinder. 4thcylinder engine is installed be-
tween 2nd and 3rd cylinder.

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3.4.2 Working principle

Knock sensor is a vibration acceleration sensor installed on engine cylinder body. You can install
one or more sensors. The sensitive part of the sensor is a piezoelectric element. The vibration of
engine cylinder body is transferred to piezoelectric crystal through mass block in the sensor. The
piezoelectric crystal generates voltage on two polar planes as a result of the pressure generated
by mass block vibration, in this way the vibration signal is converted into alternate voltage signal
output. See the following figure for frequency-response characteristic curve. Vibration signals
caused by engine knock has a frequency much higher than that of normal vibration signals, so af-
ter processing of the signals ECU can distinguish knock signals and non-knock signals.

The construction of knock sensor is divided into two types for custom use, one with the cable and
another without cable.
Sensitivity

Frequency

Figure 2-16 Frequency-response characteristic curve of knock sensor

3.4.3 Technical characteristic parameter

(1) Limit data

Value
Quantity Unit
Min Typical Max
Working temperature -40 +130 °C

(2) Characteristic data

Quantity Value Unit

Sensitivity of new sensor to 5kHz signal 26 ± 8 mV/g
Linearity between 3 and 15kHz ± 15% of 5kHz
Linearity when resonating 15 to 39 mV/g
Change during whole life Max -17%
Main resonance frequency >20 kHz
Resistance >1 MΩ
Impedance Capacitance 1200 ± 400 pF
Cable capacitance 280 ± 60 pF/m
Leakage resistance
4.8 ± 15% MΩ
(resistance between two output stitches of sensor)
Sensitivity change caused by temperature ≤ -0.06 mV/g° K

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3.4.4 Installation precaution

Knock sensor is fastened on the cylinder body with a M8 bolt through a hole in the middle of the
sensor. For the aluminum alloy cylinder, adopt 30mm bolt. For the cast iron cylinder, adopt 25mm
bolt. The tightening torque is 20 ± 5N.m. The installation position should make the sensor receive
the vibration signal from all cylinders easily. You should confirm the best installation position of
knock sensor through modal analysis to engine body. Do not let any kind of liquid, such as oil,
coolant, braking fluid and water, contact the sensor for a long time. The sensor must cling on the
cylinder body with its metal surface. Make good arrangement of wire harness of the sensor to pre-
vent the harness from resonance or it may break. Do not connect high voltage between 1# and 2#
stitch of the sensor as it may damage piezoelectric element.

3.4.5 Fault phenomenon and judgment method

• Fault phenomenon: acceleration bad etc.

• General fault cause: any liquid such as oil, coolant, braking fluid, water etc contacting the
sensor for a long time may make the sensor corrode.

• Repair precaution: (refer to installation precaution)

• Simple measuring method:

(Disassemble the joint) Turn the digital multimeter to ohm range, and connect the two meter pens
respectively to 1# and 2# stitch. The resistance value should be more than 1MΩ under normal
temperature. Turn the digital multimeter to millivolt range and knock slightly near the knock sensor
with small hammer, there should be voltage signal output.
3.5 Oxygen sensor

Diagram and stitch

Figure 2-17 Oxygen sensor

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Figure 2-18 Oxygen sensor sectional view

5. Clamp joint of
1. Cable line 2. Dish washer 3. Insulation sleeve 4. Protection sleeve
heating element
6. Heating stick 7. Contact gasket 8. Senor seat 9. Ceramic probe 10. Protection tube

Figure 2-19 Oxygen sensor sensing element sectional view

All the sensors have cable. The other end of cable is electric joint. The electric joints of oxygen
sensors which are produced by our company all have four stitches:

Stitch definition:

Front oxygen sensor:

1# connects to heat power positive electrode (white);

2# connects to heat power negative electrode (white);

3# connects to signal negative electrode (gray);

4# connects to signal positive electrode (black);

3.5.1 Installation position

Install in the front end of exhaust pipe.

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3.5.2 Working principle

The sense element of oxygen sensor is a porous ceramic tube, the external tube wall is surround-
ed by engine exhaust, and the internal tube wall is open to atmosphere. Sensing ceramic tube
wall is solid electrolyte with electric heating tube in it (see figure 2-20).

The working of oxygen sensor is realized by translating the oxygen ion concentration difference
between external and internal of sensing ceramic tube into voltage signal output. When the tem-
perature of sensing ceramic tube reaches 350°C, it has solid electrolytes characteristic. Its special
material allows the oxygen ion to pass the ceramic tube freely.

Output Voltage λ

Excessive Air Coefficient

Figure 2-20 Characteristic curve of oxygen sensor at 600°C

This characteristic makes it possible to convert the concentration difference into electric poten-
tial difference, accordingly forming the electric signal output. If the mixed gas is thick, the oxygen
ion concentration difference between internal and external of ceramic tube is high, resulting in
high electric potential difference and a mass of oxygen ion moving from internal to external. In
this case the output voltage is high (near 800mV-1000mV). If the mixed gas is thin, the oxygen
ion concentration difference between internal and external of ceramic tube is low, resulting in low
electric potential difference and only a little oxygen ion moving from internal to external. In this
case the output voltage is low (near100mV). The signal voltage has sudden change when λ=1
(see figure 2-20).

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3.5.3 Technical characteristic parameter

(1) Limit data

Value
Quantity Unit
Min Typical Max
Storage temperature -40 +100 °C
Ceramic tube end 200 850 °C
Shell hexagon head ≤ 570 °C
Working temperature Cable metal retaining ring
≤ 250 °C
and connection cable
Connection plug ≤ 120 °C
Max allowable temperature when Exhaust of ceramic tube
930 °C
the heating element make connec- end
tion (duration shall be no more than Shell hexagon head 630 °C
10 minutes for each time and ac-
cumulated duration no more than 40 Cable metal retaining ring
280 °C
hours) and connection cable
Max allowable temperature change speed of ceramic tube end ≤ 100 K/s
Ceramic element allowable temperature when exhaust side has
≤ 350 °C
condensate
Random vibration
≤ 800 m/s2
(peak value)
Harmonic vibration
Shell allowable vibration ≤ 0.3 mm
(vibration displacement)
Harmonic vibration
≤ 300 m/s2
(vibration acceleration)
Absolute
Continuous DC under 350°C μA
value ≤ 10
Max continuous AC when Exhaust temperature ≥ 350°C, f ≥ 1Hz ± 20 μA
Unleaded fuel, or allow the lead content to
Allowable fuel additive
reach 0.15g/L
The allowable value and data must be con-
firmed by the customer through the proper
Oil consumption and oil burning
scale test.
Guide value: ≤ 0.7L/1000km

2) Characteristic data

Quantity New After 250 hours test

Exhaust temperature 350°C 850°C 350°C 850°C
Sensing element’s voltage (mV) when λ=0.97 (CO=1%) 840 ± 70 710 ± 70 840 ± 80 710 ± 70
Sensing element’s voltage (mV) when λ=1.10 20 ± 50 50 ± 30 20 ± 50 40 ± 40
Sensing element’s internal resistance (kΩ) ≤ 1.0 ≤ 0.1 ≤ 1.5 ≤ 0.3
Response time (ms)
<200 <200 <400 <400
(600mV to 300mV)
Response time (ms)
<200 <200 <400 <400
(300mV to 600mV)

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(3) Sensor electric data

Quantity Value Unit

Room temperature, heating element power off ≥ 30 MΩ
Insulation resistance between
new sensor heating element and Exhaust temperature 350°C 10 MΩ
sensor joint.
Exhaust temperature 850°C ≥ 100 kΩ
Rating voltage 12 V
Continuous working voltage 12 to 14 V
At least keep 1% total life’s working voltage (ex-
Power supply voltage on plug 15 V
haust temperature ≤ 850°C)
At least keep 75 seconds working voltage ≥ (ex-
24 V
haust temperature ≤ 350°C)
Test voltage 13 V
Working voltage is 13V, reach to the heating power of heat balance
12 W
(exhaust temperature 350°C, exhaust velocity is about 0.7 m/s)
Working voltage is 13V, reach to the heating power of heat balance
5 A
(exhaust temperature 350°C, exhaust velocity is about 0.7 m/s)
Fuse of heating circuit 8 A

(4) Service life

The service life of oxygen sensor is relative to the lead content of fuel, refer to following table

Lead content of fuel (g/L) Life (km)

≤ 0.6 30000
≤ 0.4 50000
≤ 0.15 80000
≤ 0.005 (unleaded fuel) 160000

3.5.4 Installation precaution

Oxygen should be installed on the exhaust pipe which can ensure the exhaust element and meet
the set temperature limit valve. The installation position should be as closed as possible to the
engine. The thread should be set on the exhaust pipe for fixing oxygen sensor. See the following
figure:

Figure 2-21 Oxygen sensor installation position

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• Oxygen sensor installation type

Oxygen sensor should be installed with the horizontal plane angle ≥30°, and the sensor tip down-
ward, in order to avoid that condensate accumulates in the sensor housing and sensing ceramic
tube when cooling starting.

Figure 2-22 Oxygen sensor installation type

• Do no t heat up the cable metal retaining ring improperly, especially after stopping the ve-
hicle.

• Do not use the cleaning liquid or volatility solid on the oxygen sensor plug.

• The thread of oxygen sensor is M18×1.5.

• The hexagon wrench size of oxygen sensor is 22-0.33.

• Tightening torque of oxygen sensor is 40 to 60Nm.

3.5.5 Fault phenomenon and judgment method

• Fault phenomenon: idle bad, acceleration bad, harmful exhaust, fuel consumption big etc.

• General fault cause: 1. Wet vapor enters into sensor internal, temperature changes rapidly,
probe fractures; 2. Oxygen sensor “poisoning” (Pb, S, Br, Si).

• Repair precaution: forbid using the cleaning liquid, oiliness liquid or volatility solid on oxygen
sensor when repairing.

Simple measuring method:(Disassemble the joint) Turn the digital multimeter to ohm range, and
connect the two meter pens respectively to 1#(white) , 2# (white) stitch of the sensor, the resis-
tance value is 1~6Ω in normal temperature.

(Assemble the joint) Under idle state, when oxygen sensor is reaching to the working temperature
350°C, turn the digital multimeter to DC volt range, and connect the two meter pens respectively
to the 3#(gray), 4# (black)stitch of the sensor, the voltage should quickly fluctuate between 0.1-
0.9V at this time.

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3.6 Speed sensor (only for system without distributor)

Diagram and stitch

Figure 2-23 Speed sensor

1. Shielded line 2. Permanent magnet

3. Sensor shell 4. Installation bracket

5. Soft magnet core 6. Coil

7. Air clearance 8. 60-2 gear ring

Figure 2-24 Speed sensor sectional view

Stitch: There are two types of speed sensor connector produced by our company used on M7.9.7
electric control system. See following figure. Accordingly there are two stitch definitions. The sys-
tem adopts connectors as shown in Figure 2-25joint.

Figure 2-25 Figure 2-26

1# connects to shielding 3# connects to shielding

2# and 3# connect to signal line 1# and 2# connect to signal line

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3.6.1 Installation position

Engine rear wheel plane

3.6.2 Working principle

Working together with the pulse plate, Speed sensor is used to supply engine speed information
and crankshaft TDC information in ignition system without distributor. The speed sensor is made
of a permanent magnet with a coil around it outside. The pulse plate is a gear plate with 60 teeth
originally, but two teeth are blank. The pulse plate is installed on the crankshaft, and rotates along
with crankshaft. When the speed sensor’s end which is closed to gear tip is passing, the pulse
plate made of iron magnet material cuts the magnetic line of permanent magnet in speed sensor,
generating induced voltage, and outputting the voltage as speed signal.

3.6.3 Technical characteristic parameter

(1) Limit data

Value
Quantity Unit
Min Typical Max
Loop area -40 +150 °C
Transition area Mixed Mixed °C
Lead area -40 +120 °C
Storage temperature -20 +50 °C
Allowable
Temperature when not running -40 +120 °C
temperature of
PUR lead speed Long-term temperature when running -40 +120 °C
sensor (refer to
Short-term temperature 150 hours +150 °C
following figure)
when running 380 hours +140 °C
150 hours +150 °C
Lead area in whole service
380 hours +140 °C
life
1130 hours +130 °C
Loop area -40 +150 °C
Transition area Mixed Mixed °C
Lead area -40 +130 °C
Allowable
Storage temperature -20 +50 °C
temperature of
H&S lead speed Temperature when not running -40 +130 °C
sensor (refer to
Long-term temperature when running -40 +130 °C
following figure)
Short-term temperature when running +150 °C
Lead area in whole ser- 500 hours +150 °C
vice life 200 hours +160 °C
Anti vibration ability in each 20 to71Hz Acceleration ≥40 m/s2
plane in 168 hours 71 to 220Hz Swing ≥0.2 mm
Allowable magnetic field intensity of rightabout outside
≤2 kA/m
magnetic field
Insulation resistance (10s,test New state ≥1 MΩ
voltage 100V) Using time end ≥100 kΩ
Withstand voltage (1 to3 seconds, 1200V AC) Can not breakdown

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Figure 2-27 Three temperature area of speed sensor

2) Characteristic data

Value
Quantity Unit
Min Typical Max
Resistance under 20°C 731 860 989 Ω
Inductance 310 370 430 mH
Output voltage when crankshaft at 416 r/m >1650 mV

3.6.4 Installation precaution

• Only take out speed sensor from packaging material before installation on vehicle or test
equipment.

• Press speed sensor in place, rather than use hammered.

• Recommend to adopt M6×12 bolt with partial micro seal to fix speed sensor.

• Tightening torque 8 ± 2Nm.

• Gas clearance between speed sensor and pulse plate tooth tip: 0.8 to 1.2mm.

• Diameter(see following figure): : 4.7mm

size

Figure 2-28 Speed sensor installation

3.6.5 Fault phenomenon and judgment method

• Fault phenomenon: can cot start etc.

• General fault cause: manmade fault.

• Repair precaution: make installation by pressing the sensor in place, rather than using ham-
mered.

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• Simple measuring method:

(Disassemble the joint) Turn the digital multimeter to ohm range, and connect the two meter pens
respectively to 2#, 3 stitch of sensor. The rating resistance is 860Ω ± 10% at 20°C.

(Assemble the joint) Turn the digital multimeter to DC volt range, connect the two meter pens re-
spectively to 2#, 3# stitch, start the engine, there should be voltage output at this time.(it is sug-
gested to use vehicle special oscillograph to inspect)

Figure 2-29 Test oscillogram

3.7 Phase sensor

Diagram and stitch (Only used on non-distributor system)

Figure 2-30 Phase sensor

Stitch: Mark 1 indicates it contacts to ground.

Mark 2 indicates signal output

Mark3 indicates it contacts to power positive

3.7.1 Installation position

On camshaft end cover

3.7.2 Working principle

The sensor is used to work together with induction sensor of pulse plate without distributor to sup-
ply crankshaft phase information to ECU, that is, distinguishing the crankshaft compress TDC and
exhaust TDC.

The sensor is designed by the Hall Principle: Hall voltage is influenced by changing magnetic field
induction intensity.

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B Hall sensor principle

When a current passes through a semi-
conductor slice, a Hall voltage UH is gen-
erated in the dextral direction of current. Its
value is in direct proportion with magnetic
field induction B (vertical with current IS)
and current IS. Hall voltage is influenced
by changing magnetic field induction inten-
sity B.
I
UH
S

Figure 2-31 Hall Effect principle diagram

Figure 2-32 Phase sensor working diagram Figure 2-33 Phase sensor working diagram
(1) (2)

3.7.3 Technical characteristic parameter

Limit data

Value
Quantity Unit
Min Typical Max
Environmental temperature -30 +130 °C
Installation clearance 0.5 1.5 mm
Supply voltage 4.5 24 V

3.7.4 Installation precaution

This sensor only has one hole on its shell for fastening.

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3.7.5 Fault phenomenon and judgment method

• Fault phenomenon: harmful emission, fuel consumption increasing etc.

• General fault cause: manmade fault.

• Simple measuring method:

(Connect joint) Open the ignition switch but do not start engine, turn the digital multimeter to DC
volt range, connect the two meter pens respectively to 1#, 3# stitch of sensor, and ensure that
there is 12V reference voltage. Start the engine, use oscillograph to check whether 2# stitch sig-
nal is normal.

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3.8 Electronic controller unit

Power supply 6 x 2,2A Fuel injector 1

Ignition 70V
Main relay Fuel injector 2
5V output 1 Fuel injector 3
5V output 2 Motronic-IC
Crankshaft sensor Fuel injector 4
Selfdiagnosis
- k line 80C167CR
Output supply Idle regulator
Output 2 x 2,2A Carbon canister control
stages 45V
valve
MIL
Knock sensor Moronic-IC 2 x 2,7A
Gas recycle control
45V
5V-Flash Fault signal lamp
Intake pressure sensor 4 x 0,6A Fuel pump relay
512 KB
Oxygen sensor 45V A/C relay
Battery Fan 2
Coolant temperaturesensor RAM Fan 1
In take temperature 32 KB
Gas recycle potentiometer
Analog
Gas recycle pressure interface
Throttle position network Output 4x50 mA
MIL request Port stages
A/C temperature Expander
A/C pressure Engine speed output
Reservation
Oxygen sensor
Alternator output
Accelerating sensor
Burning level signal
Reservation EEPROM Ign. Ignition control 2
Reservation 1024 Byte
Ign. Oxygen sensor
Alternator input
driver
MOSFET heating (LSH25)
Camshaft signal Ignition control 1
Vehicle Speed signal driver
Oxygen sensor
E.S.COD1 Digital MOSFET
heating (LSH25)
E.S.COD2 interface
Reservation
Reservation network
Stepper Reservation
A/C switch signal
Reservation
A/C compressor signal Motor Reservation
Reservation Drive Reservation

Anti -theft cipher MUX

Step motor A
Output 4x0,6 A Step motorB
Step motorC
stages
Step motorD

CAN bold: basic /thin: options

Can bus

CAN Bus Driver

Figure 2-34 ECU electrical principle diagram

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Figure 2-35 ECU outline

3.8.1 Installation position

Passenger chamber side

3.8.2 Working principle

(1) Function

• MPI

• Control ignition

• Idle control

• Knock control

• Supply sensor’s power supply: 5V/100mA

• Closed loop control, with self-adaptation

• Control carbon canister control valve

• A/C switch

• Engine fault indicator

• Fuel ration correction

• Engine speed signal’s output (TN signal)

• Speed signal’s input

• Fault self-diagnosis

• Accept engine load signal etc.

(2) ECU stitch definition:

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Stitch Connector Stitch Connector

Rear oxygen sensor heating circuit control
1 37 Carbon canister valve signal input end
end,lower the high leve
Front oxygen sensor heating circuit control
2 38 Reserved
end,lower the high level
3 1#ignition coil signal control end 39 Sensor signal grounding 1
4 Vacuum solenoid valve signal control end 40 Sensor signal grounding 2
5 ECM grounding 41 coolant temperature signal input end
6 Reserved
7 2#ignition coil signal control end 42 Camshaft signal input end
Input ECM power((Non-continuous)),turn on igni-
8 tion switch NO,main relay pull-in and voltage is 43 ECM grounding
12V
9 Engine speed output end 44 Air conditioner request signal
Air conditioner medium-pressure switch signal
10 45 Front oxygen sensor signal input end
input end.
11 Reserved 46 Crankshaft position sensor B end
12 Power steering switch signal input end 47 Crankshaft position sensor A end
13 Reserved 48 ECM grounding
14 Reserved 49 3RD cylinder injector signal control end
15 Diagnose K line 50 IST cylinder injector signal control end
Input ECM power((Non-continuous)),turn
16 lasting power, mormal electricity 51 on ignition switch NO,main relay pull-in
and voltage is 12V
Water and air conditioner high speed fan
17 Input ECM power,turn on ignition switch ON,12V 52
relay lower control end
18 Throttle position sensor power supply (5V ) 53 Reserved
Intake temperature/pressure sensor power sup-
19 54 Reserved
ply (5v)
20 Reserved 55 Reserved
21 Step motor phase B ,ON 12V 56 Reserved
22 Step motor phase A, ON 12V 57 Reserved
23 Reserved 58 Reserved
Rear windscreen heating switch and blower
24 59 Intake pressure signal input end
compensate signal input end
25 Intake temperature signal input end 60 Oil pump relay lower control end
26 Throttle position signal input end 61 Allowable air conditioner signal
Water tank and air conditionerlow speed
27 Reserved 62
fan relay lower control end
28 Reserved 63 2ND cylinder injector signal control end
29 Rear oxygen sensor signal input end 64 4TH cylinder injector signal control end
30 Knock sensor A end
31 Knock sensor B end
32 Main relay lower control end
33 CAN-H
34 CAN-L
35 Step motor phase C
36 Step motor phase D

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3.8.3 Technical characteristic parameter

Limit data

Value
Quantity Unit
Min Typical Max
Running nor-
9.0 16.0 V
Battery voltage mally
Limited function 6.0 to 9.0 16.0 to 18.0 V
Limit value and time of tolerable Part of function available, can
26.0V 60 s
battery over voltage execute fault diagnosis
Working temperature -40 +70 °C
Storage temperature -40 +90 °C

3.8.4 Installation precaution

• Pay attention to static protection when installing

• Pay attention to plug stitch protection

3.8.5 Fault phenomenon and judgment method

• Fault phenomenon: idle unstable, accelerating bad, can not start, idle too high, harmful emis-
sion, starting hard, A/C failure, fuel injector control failure, flameout etc.

• General fault cause: 1. because the external device electric overloads, it causes the ECU
internal parts burning and failure; 2. because water enter into ECU, it causes circuit board
rusting.

• Repair precaution: 1. do not disassemble the ECU randomly in repair process; 2. please
firstly disassemble the battery jar end and wait for over 1 minute before disassembling the
ECU; 3. do disassemble ECU before doing welding, and keep ECU properly after disassem-
bling; 4. never install any circuit on ECU connection line.

• Simple measuring method:

1. (Connect the joint) Use engine data K;

2. Check whether ECU power supply, grounding circuit are normal;

3. Check whether the external sensor works normally, whether output signal is credible, and
whether its circuit is good;

4. Check whether the actuator works normally, whether its circuit is good;

5. At last replace ECU and do the test.

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3.9 Electric fuel pump ECU13.6 model

Diagram and stitch

Main relay

Figure 2-36 Electric fuel pump Figure 2-36 Electric fuel pump circuit diagram

Stitch: There are two stitches on the electric oil pump and they connects oil pump relay. Oil pump shell
near the two stitches is marked with “+“ ”-”, which means positive electrode and negative electrode.

3.9.1 Installation position

In fuel tank

3.9.2 Working principle

Electric fuel pump is made up of DC motor, van pump and end cover (integrating check valve, re-
lief valve and anti-electromagnetic interference element), see figure 2-37.

The pump and motor are installed on same shaft and closed in the same shell. Gasoline is filled
up around the pump and motor within the shell for cooling and lubrication. The battery supplies
power to electric fuel pump through fuel pump relay, which switch on the electric fuel pump’s cir-
cuit only in starting and when engine is running. When the engine stops running because of acci-
dent, the fuel pump will automatically stop running.

1. End cover

2. Motor

3. Fuel path

4. Van pump

Figure 2-37 Electric fuel pump sectional view

The max pressure of electric fuel pump outlet is decided by relief valve (between 450 and
650kPa). As the system has no fuel return, the pressure of whole system is decided by fuel pres-
sure regulator (the general value is 350kPa).

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According to the demand of engine, electric fuel pumps can have different flow rate. For produc-
ing, electric fuel pump of EKP13 series with the same structure adjusts electromotor rotating
speed by adjusting coil turns and therefore adjusts flow rate .So do not use the electric fuel pump
of one vehicle on another vehicle randomly.

3.9.3 Technical characteristic parameter

(1) Limit data

Value
Quantity Unit
Min Typical Max
Working voltage 8 14 V (DC)
System pressure 350 kPa
Outlet pressure 450 650 kPa
Environmental temperature
-40 +80 °C
(for storing and transporting)
Allowable fuel temperature -30 +70 °C
Allowable vibration acceleration 20 m/s2

(2) Characteristic data

The flow rate of electric fuel pump is in direct proportion with voltage under certain supply fuel
pressure. Oil pump is different in different vehicle factories.

3.9.4 Installation precaution

The electric fuel pump should store in closed original packing box. The maximum allowable stor-
age time is six months after installed on vehicle. As spare part, its max storing time is 4 years.
When the allowable storage time expires, the performance of pump should be checked again by
manufacturer. At storage place, the pump shall be kept away from influence of atmosphere pres-
sure and the original packing can not be damaged.

Electric fuel pump of EKP13 series is only applied in oil tank. When installing the fuel pump, you
must install the mesh whose dimension is less than 60μ or the fuel inlet port filter screen agreed
with customer. Notice not to make the fuel spray injecting from vent hole inject on fuel inlet port fil-
ter screen, fuel pump bracket or fuel tank wall. Be careful when carrying the fuel pump to protect
the fuel inlet port filter screen from load and impact. The fuel pump should be taken from plas-
tic packing material carefully only when installing. The protection cover can only be taken away
when the fuel pump will be installed at once. Never take away the fuel inlet port filter screen. Any
foreign matter entering into fuel pump fuel inlet port or filter screen can cause damage to the fuel
pump.

Pay attention to cleaning when installing the fuel pipe. You must clean the inside of fuel pipe.
Please only use new fuel pipe clamp. Make sure the clamp is at the right position and follow man-
ufacturer’s instruction.

Do not hold the pump at the fuel inlet port or filter screen.

To prevent damage to the fuel pump, do not run the pump under dry condition. Do not use any
damaged pump. After the fuel tank drops to the ground, the fuel pump in the fuel tank must be re-
placed.

It’s prohibited to impose pressure on the oil inlet plate and mechanical stress can’t be imposed at
the caulking. Oil pump clamp must fall within the prescribed limits, see below.

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The prescribed limits

of Oil pump clamp

Mechanical stress
can’t be imposed
at the caulking

Figure 2-38 prescribed limits of oil pump clamp

In case of return to factory, please attach delivery document, inspection document and package
label together to the pump in specified package. If the pump has been used, flush it with test fluid
and let it dry in air. It is not allowed to blow it dry. Considering about the safty,we don’t accept the
oil pump with fuel.

3.9.5 Fault phenomenon and judgment method

• Fault phenomenon: running noise big, accelerating bad, starting hard etc.

• General fault cause: using poor quality fuel, leading to: 1. colloid accumulating forms insulat-
ing layer; 2. fuel pump bushing and armature are locked up; 3. fuel surface sensor compo-
nents corrodes.

• Repair precaution:

1. Only replace with a pump with the same part number as the original, as fuel pumps which
have same appearance and can be installed in place may have different flow rate;

2. Do not long-time running under dry condition to prevent damage;

3. Pay attention to cleaning the fuel tank and pipe as well as replacing the fuel filter when re-
placing the fuel pump.

• Simple measuring method:

(Disassemble the joint) Turn the digital multimeter to ohm range, connect the two meter pens re-
spectively with the 1# and 4# stitch of fuel pump and measure the resistance. It shall be near to
1Ω.

(Connect the joint) Connect the fuel press gauge on fuel inlet pipe, start the engine, check wheth-
er the fuel pump is running; if not running, check whether there is power supply voltage at “4#”
stitch; if running, check whether the fuel pressure is about 350kPa under idle condition; depress
the acceleration pedal to the engine speed 2500rpm, check whether the fuel pressure is about
350kPa at this time.
3.10 Electromagnetic Fuel injector

Diagram and stitch

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Figure 2-40 Electromagnetic fuel injector cir-

Figure 2-39 Electromagnetic Fuel injector
cuit diagram

Stitch: Each fuel injector has

Two stitches. One is the 87#stitch which is on one side of the shell with the plus sign and con-
nects with main relay output end. The other one separately connects ECU 27#, 6#, 73#, 47#
stitch.

Figure 2-41 Fuel injector on fuel rail Figure 2-42 Fuel injector sectional view

1. O-shape ring 2. Filter screen 3. Fuel injector body with power plug 4. Coil
6. Valve needle with coil arma-
5. Spring 7. Valve seat with orifice plate
ture

3.10.1 Installation site

On intake manifold at one end of intake valve

3.10.2 Working principle

ECU sends electronic pulses to the coil of fuel injector, and forms magnetic force. When the mag-
netic force rises enough to overcome the resultant force formed with return spring pressure, nee-
dle valve gravity and friction force, the needle valve begins to rise, and the fuel injection starts.
When the fuel injection pulses stop, the return spring pressure will make the needle valve closed
again.

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• The type of EV6 electromagnetic fuel injector;

- It can be divided into long type and standard type according to length;

- It can be classified as type B ( single-hole single-beam ), C ( four-hole cone ) and type E (

four- hole double-beam) by spray shape.

• The choosing of type is based on the engine and intake manifold.

3.10.3 Technical characteristic parameter

3.10.3.1 Limit data

Value
Quantity Unit
Min Typical Max
Storage temperature (original packing) -40 +70 °C
Allowable temperature of fuel injector in vehicle
+140 °C
(when not working)
Continuous -40 +110 °C
Working temperature of Short time after hot
fuel injector starting (about 3 min- +130 °C
utes)
Allowable fuel tempera- Continuous +70 °C
ture in the fuel injector
Short time (about 3
inlet opening +100 °C
minutes)
The temperature when the fuel flow deviation
-40 +45 °C
reaches 5% compared with that at 20°C
Fuel wetness is allowed in O-shape area, but no leak is al-
O-shape ring leakage allowance at -35 to -40°C
lowed.
Max allowable vibration acceleration (peak value) 400 m/s2
Power supply voltage 6 16 V
Insulation resistance 1 MΩ
Tolerable internal fuel pressure 1100 kPa
Tolerable bending stress 6 N•m
Tolerable axial stress 600 N

3.10.3.2 Characteristic data

Value
Quantity Unit
Min Typical Max
Working pressure (pressure difference) 350 kPa
Fuel injector resistance at 20°C 11 17 Ω

3.10.3.3 Allowable fuel

The fuel injector can only use the fuel stipulated in Vehicle-use Gasoline, the National Standards
of Peoples Republic of China GB 17930-1999, and Hazardous Materials Control Standard for
Motor Vehicle Gasoline, the National Environmental Protection Standard GWKB 1-1999. It would
be specially mentioned that gasoline will deteriorate as a result of being kept for too long, in par-
ticular, the gasoline used by the taxi with engine using both LPG and gasoline. As LPG is used
for fuel for a long term while gasoline is just for starting, the car consumes very little gasoline, so

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the gasoline left in the fuel tank can easily get oxidized at a rather high temperature caused by
long-term operation of the fuel pump. What’s worse, the fuel injector will be blocked, or even to be
damaged.

3.10.4 Installation precaution

• Confirm BOSCH logo and product number.

• Make sure that specified plug is used for specified fuel injector. Don’t mixed it .

• To make it easier to install, you are suggested to lay on a coat of silicon-free engine oil on
the upper O-shape ring connected to the fuel rail. Be careful not to contaminate inside the
fuel injector and the orifice.

• Put the fuel injector into the fuel injector seat perpendicularly, and then fix it on the seat by
clamps.

Notes:
1. Fuel injector clamp is classified to axial location clamp and radial location clamp ac-
cording to its location mode, so do not use the wrong one.

2. For the installation of the axial-location fuel injector, make sure the bayonet in the
middle of clamp is completely inserted into the groove and the groove on both sides
of the clamp is completely locked the flanging of fuel injector seat.

3. When installing the fuel injector in need of both axial location and radial location, the
axial location clamp shall be used to make the located block of the fuel injector and
the location pin of the fuel injector seat well placed in the groove corresponding to the
clamps respectively.

4. In case of two grooves in the fuel injector, be careful not to clamp it wrong. You can
refer to the installation location of the original.

• The fuel injector shall be installed with hands. Do not strike the fuel injector by using tools
such as hammer.

• When removing or reinstalling the fuel injector, the O-shape ring must be replaced. Now do
not damage the sealing face of the fuel injector.

• Do not pull out the supporting bead of the O-shape ring from the fuel injector. Be careful to
install and avoid damaging the pipe head of the fuel injector, O-shape ring, supporting bead,
orifice plate and plug. Do not use it if any damage incurs.

• After the installation of fuel injector, test the fuel rail assembly for tightness. If no leakage, it
is considered to be qualified.

• The failure components shall be removed manually: first, remove the clamp of fuel injector;
then, pull out the fuel injector from the fuel injector seat. Make sure the fuel injector clean af-
ter installation to avoid contamination.

3.10.5 Fault phenomenon and judging method

• Fault phenomenon: idle speed, bad acceleration, start failure (hard starting) etc.

• General fault cause: for lack of maintenance, colloid accumulates inside the fuel injector and
thus the fuel injector fails.

• Maintenance cautions: (refer to the installation cautions)

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• Simple measuring method:

(Remove the adapter) Turn the digital multimeter to ohm range, and contact the two probes to two
stitches of fuel injector respectively. The rated resistance is 11-17Ω at 20°C.

Recommendation: use special cleaner & analyzer to clean the fuel injector thoroughly per
20,000kM
3.11 Idle actuator stepper motor

Diagram and stitch

Figure 2-44 Idle actuator stepper motor circuit

Figure 2-43 idle stepper motor
diagram

Stitch: Stitch A connects to ECU 65#stitch

Stitch B connects to ECU 66#stitch

Stitch C connects to ECU 67# stitch

Stitch D connects to ECU64# stitch

3.11.1 Installation site

On the throttle body.

3.11.2 Working principle

Stepper motor, a mini-size motor, is made of several steel stators in a circle and a rotor (refer to
figure 2-45). Each steel stator winds a coil on it; rotor is a permanent magnet with a nut in the
center. All stator coils are electrified all the time. As long as you change the current direction of its
certain coil, the rotor will turn at an angle. When the current direction of each stator is changed
in proper order, a rotating magnetic field will form to make the rotor made by permanent magnet
rotate in certain direction. If reversing the order, the rotation direction of rotor will be reversed too.
The nut connected in the center of the rotor will drive a screw rod. As the screw rod is designed
not to rotate, it can only move in the axial direction, also called linear axis. There is a choke plug
at the end of the screw rod, so the choke plug can retract or extend so as to increase or reduce
the sectional area of the by-pass air channel of idle speed actuator, until it is blocked. The step
width is equal to the value that 360 ° is divided by the number of stator or coil and that of this
stepper motor is 15° . Accordingly every step distance moved by the screw rod is fixed. ECU can
control the step number of the stepper motor through controlling the times of changing the current

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direction of the coil so as to regulate the sectional area of the by-pass channel and the air flow
running through. In general, the air flow has a linear relation with step width. Once the current di-
rection of certain coil is changed, the rotor will turn in a certain angle, called step width. There is a
spring behind the plug at the end of screw rod, referred as below. The available force in the direc-
tion of plug extension is equal to the force of stepper motor plus spring force; while in the direction
of plug retraction it is equal to the force of stepper motor minus spring force.

Figure 2-46 Installation diagram of idle step-

Figure 2-45 Profile of idle stepper motor
per motor

3.11.3 Installation precaution

• Install with two M5×0.8×14 bolts.

• Tightening torque for bolt is 4.0 ± 0.4Nm.

• Install with spring washer, and bond with binder.

• The axis of idle actuator with stepper motor shall not be installed horizontally or below the
level, to avoid the condensed water entering.

• Do not force in any type in the axial direction to try to press or pull out the axis.

Before placing the idle actuator with stepper motor into throttle body, its axis should be placed at
a fully retracted position.

3.11.4 Fault phenomenon and judging method

• Fault phenomenon: high idle speed, idling stop etc.

• General fault cause: accumulation of dust, fuel gas, etc causes the by-pass air channel par-
tially blocked and thus, the stepper motor cannot perform normal idle regulation.

• Maintenance cautions: 1. Do not force in any type in the axial direction to try to press or pull
out the axis. 2. Before placing the idle actuator with stepper motor into throttle body, its axis
should be placed at a fully retracted position. 3. Attention should be paid to cleaning and
maintaining the by-pass air channel; 4. After disassembling the battery jar or ECU, do auto
tuning to step motor in time.

The auto tuning method of M7 system is: open the ignition switch but do not start the engine im-
mediately, and then start the engine after 5 seconds,. If the engine is found at idle speed this mo-
ment, repeat the steps above.

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Simple measuring method: (remove the adapter) Turn the digital multimeter to ohm range, and
contact the two probes to AD stitch and BC stitch of regulator respectively. The rated resistance is
53 ± 5.3Ω at 25°C.
3.12 Double spark ignition coil (for 4-cylinder engine without distributor system)

Diagram and stitch

Double spark ignition

Main relay 87#

Figure 2-48 Double spark ignition coil circuit

Figure 2-47 Double spark ignition coil
diagram

NOTICE
the system has two ignition coils, of
which the secondary connects to two
cylinders, that is, to ignite 1# cylinder
and 4# cylinder at the same time, and 2#
cylinder and 3# cylinder simultaneously.

Stitch definition:

1-4 cylinder ignition coil

Low pressure side:

1. primary winding stitch of 1# coil connects to the main relay 87#;

2. primary winding stitch of 2# coil connects to 5# stitch of ECU;

High pressure side: two secondary winding terminals connect to the spark plug of homonymy en-
gine cylinder through live line respectively;

2-3 cylinder ignition coil

Low pressure side: primary winding stitch of 1# coil connects to the main relay 87#;

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primary winding stitch of 2# coil connects to 2# stitch of ECU;

High pressure side: two secondary winding terminals connect to the spark plug of homonymy en-
gine cylinder through live line respectively;

3.12.1 Installation site

On the engine

3.12.2 Working principle

The ignition coil is made up of primary winding, secondary winding, iron core, shell, and so on.
When the grounding channel of certain primary winding is connected, the primary winding starts
to charge. Once it is cut off by ECU, charging will be disabled. In the meantime the secondary
winding induces high-voltage electricity, and makes the spark plug discharge. What’s different
with the ignition coil with distributor is that each end of the ignition coil secondary winding con-
nects to a spark plug, so the two spark plugs will ignite simultaneously. The two primary windings
will power on and off alternately. Accordingly, the two secondary windings will discharge alternate-
ly.

3.12.3 Technical characteristic parameter

Characteristic data

Value
Quantity Unit
Min Typical Max
Working voltage 6 14 16.5 V

Performance Primary resistance 20°C 0.70 0.8 0.90 Ω

parameter Secondary resistance 20°C 9.68 11 12.32 kΩ
Temperature range -40 +110 °C

3.12.4 Fault phenomenon and judging method

• Fault phenomenon: starting failure etc.

• General fault cause: too large current causes burning, damaging etc.

• Maintenance cautions: do not use “short-circuit testing fire” to test the ignition function, to
avoid damaging electronic controller.

• Simple measuring method: (remove the adapter) turn the digital multimeter to ohm range,
and contact the two probes to the two stitches of primary winding respectively, the rated re-
sistance is 0.70-0.90Ω at 20°C; secondary winding resistance is 9.68-12.32kΩ.

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3.13 Carbon canister control valve

Diagram and stitch

To main relay

Carbon canister
control valve

Figure 2-49 Carbon canister control valve Figure 2-50 Carbon canister control valve
TEV-2 TEV-2 circuit diagram

Stitch: Carbon control valve only has two stitches. One connects to 87#stitch of main relay output,
and the other one connects to 46#stitch of ECU.

3.13.1 Installation position

On the vacuum pipeline of carbon canister-intake manifold

3.13.2 Working principle

Figure 2-51 Carbon canister control valve Figure 2-52 Carbon canister control valve
sectional view installation diagram

The carbon canister control valve is made of electromagnetic coil, keeper and valve. There is a fil-
ter screen on the intake position. On the one hand the air current flowrate flowing through the car-
bon canister is depending on the duty cycle of electric pulse which is output from ECU to carbon
canister control valve; on the other hand it is also relative with the pressure difference between in-
let and outlet of carbon canister control valve. When there is no electric pulse, the carbon canister
control valve is closed.

The flowrate of different type carbon canister control valve is different under full opening condition,

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namely 100% duty cycle. The following figure shows two kinds of typical flowrate curve. From the
figure, under the same pressure difference of 200mbar, the flowrate is 3.0m3/h when A type car-
bon canister control valve is full opening, while the flowrate of B type is 2.0m3/h. (this item is B
type)

Figure 2-53 carbon canister control valve flowrate diagram

3.13.3 Technical characteristic parameter

(1) Limit data

Value
Quantity Unit
Min Typical Max
Working voltage 9 16 V
One minute overvoltage 22 V
Min starting voltage 7 V
Min voltage drop 1.0 V
Allowable working temperature -30 +120 °C
Short time allowable working temperature +130 °C
Allowable storage temperature -40 +130 °C
Allowable pressure difference between inlet and outlet 800 mbar
Allowable on-off times 108
Allowable vibration acceleration on product 300 m/s2
Leakage quantity when pressure difference is 400mbar 0.002 m3/h

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(2) Characteristic data

Value
Quantity Unit
Min Typical Max
Rating voltage 13.5 V
Resistance when +20°C 26 Ω
Current under rating voltage 0.5 A
Control pulse frequency 30 Hz
A type 7 ms
Typical control pulse width
B type 6 ms

Flowrate when pressure difference A type 2.7 3.0 3.3 m3/h

is 200mbar, duty cycle is 100% B type 1.7 2.0 2.3 m3/h

3.13.4 Installation precaution

The connection of carbon canister control valve and carbon canister, intake manifold refers to fig-
ure 2-54.

• To avoid solid sound passing, commend to hanging install the carbon canister control valve
on the tube.

• Must make the air current direction accord with the regulation.

• Must prevent the foreign body entering as particulate from carbon canister or tube to carbon
canister control valve according to proper measure as filtrating, cleaning.

• Commend to install a corresponding protection filter (mesh size>50μm) on carbon canister

inlet.

3.13.5 Fault phenomenon and judgment method

• Fault phenomenon: function failure etc.

• General fault cause: because the foreign body enters into internal, it causes corrosion or bad
sealing.

• Repair precaution: 1, Must make the air current direction accord with the regulation when
installing; 2, When finding the control valve failure because of black grain inside the valve
body, and need to replace the control valve, please check the carbon canister condition; 3,
Try best to avoid the water, oil etc liquid entering into valve in repair process; 4, To avoid sol-
id sound passing, commend to hanging install the carbon canister control valve on the tube.

• Simple measuring method:

(Disassemble the joint) Turn the digital multimeter to ohm range, and connect the two meter pens
respectively with two stitches of carbon canister control valve, the rating resistance is 22~30Ω at
20°C.

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3.14 Fuel pressure regulator

Diagram

Figure 2-54 Fuel pressure regulator Figure 2-55 Fuel pressure regulator sectional
view

3.14.1 Installation position

In fuel pressure regulator seat on fuel pump

3.14.2 Working principle

Showing as the figure 2-66, a sheet of fixable film which is made by rubber-fiber divides the fuel
pressure regulator into two chambers. The upper chamber with a spring in it is open to atmo-
sphere. The lower chamber is full of fuel. The underside of film gets the fuel pressure, and the
upside gets the atmosphere pressure and spring pressure. The film can deform to drive the valve
seat, making the valve open or close, but because the deformation is too small, the spring force
can be considered to keep invariant. So the on-off of valve is mainly decided by the pressure dif-
ference between fuel pressure in lower chamber and atmosphere pressure in upper chamber. As-
sume that the valve is closed in the beginning, later because the fuel pressure rises, it causes the
pressure difference between upper and lower chamber increasing, finally the film is pushed up by
fuel pressure, the valve turns on, the fuel releases to fuel tank through the fuel back port in the
center of pressure regulator, the fuel pressure drops till the valve turns off. So when changing the
engine working condition, the difference between fuel system pressure and atmosphere pressure
keeps invariant in the main.

3.14.3 Technical characteristic parameter

(1) Limit data

Value
Quantity Unit
Min Typical Max
Leakage flowrate when pressure difference is 280kPa 9 cm3/min
Continuous working allowable temperature -40 +80 °C
Fuel max allowable temperature +80 °C
Max allowable pressure drifting at -30°C (reversible) -2% +5%
Max allowable pressure drifting at +80°C(reversible) -5% +2%
Max allowable acceleration peak value 100 m/s2
Max allowable pressure pulse value at inlet position 100 kPa

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(2) Characteristic data

Value
Quantity Unit
Min Typical Max
Rating pressure difference when the flowrate Q is 80 l/h 350 kPa
The working pressure changing value when the flowrate is
17.5 kPa
changing in the range from 15 to 140 l/h
Flowrate range 10 220 L/h
Slope of characteristic curve 0.14 kPa/ L/h

(3) Fuel demand

The fuel pressure regulator can be used to the stated fuel which is in compliance with the country
standard.

Fuel pressure regulator also can be used to the fuel which contains carbinol or ethanol below
15% volume.

3.14.4 Installation precaution

• Lubricate the O type ring lightly with clean, silicone-free engine oil or other lubrication oil au-
thorized by BOSCH.

• Do not make the deformation of pressure regulating valve when assembling and disassem-
bling.

• Must replace new O type ring when disassembling and reusing the pressure regulating
valve, if the pressure regulating valve bears the pressure more than 1500kPa, replace it.

• The pressure regulating valve which has experienced rupture test or durability test can not
be used on the vehicle.

3.14.5 Fault phenomenon and judgment method

• Fault phenomenon: Too low or too high fuel pressure causes starting hard etc.

• General fault cause: Because of long-term using and being short of maintenance, it causes: 1,
filter screen blocks; 2, grain impurity causes big leakage; 3, manmade mechanical damage.

• Repair precaution: In repair process: 1, forbid impacting the diaphragm element with high
pressure gas; 2, forbid cleaning it with strong corrosion liquid; 3, forbid making deformation
with external force. Simple measuring method: Connect the fuel pressure gauge on fuel inlet
pipe, start the engine, make the engine run idle, check whether the fuel pressure is about
350kPa; depress the accelerating pedal till the engine speed is 2500rpm, and check whether
the fuel pressure is about 350kPa at this time.

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3.15 Steel fuel distributor assembly

Diagram

Figure 2-56 Fuel distributor assembly

3.15.1 Installation position

On intake manifold

3.15.2 Working principle

Fuel distributor assembly is made of fuel distributor (KVS) and fuel injector (EV). And it is used to
store and distribute the fuel.

3.15.3 Technical characteristic parameter

Limit data

Value
Quantity Unit
Min Typical Max
Working temperature when fuel distributor and O type ring is
-40 +120 °C
properly connected
Highest working temperature at 15 minutes under wet state +130 °C
Max allowable vibration acceleration peak value 300 m/s2

The system pressure refers to characteristic parameter of pressure regulating valve, the fuel de-
mand refers to characteristic parameter of fuel injector, the sealing requests no fuel leakage un-
der working pressure.

The inner diameter of fuel rubber pipe is Φ7.9 ± 0.3.

3.15.4 Installation precaution

• Clamp the joint of fuel intake pipe and rubber pipe closely with clamp hoop, the using clamp
hoop type must match with rubber pipe, and protect the sealing of connection between fuel
inlet pipe and rubber pipe.

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• There is no crack, scaur, groove, burr and corrosion on fuel inlet pipe wall.

• Before assembling the fuel distributor assembly, lubricate the lower O type ring of fuel injec-
tor with cleaning lubrication oil.

3.15.5 Fault phenomenon and judgment method

The sealing of fuel distributor can test with pressure drop method: do the test to the O type ring of
fuel distributor’s injector. At 4.5 bar, the test leakage limit value ≤ 1.5cm3/min.

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4. Maintenance and Diagnosis procedure of M7 according to the DTC

Explanation:

1. Ensure the fault is stable malfunction before inspecting, otherwise it will cause the false diag-
nosis.

2. The multimeter mentioned hereunder refers to digital multimeter. It is not allowed to use the
finger multimeter to check the injector system circuit.

3. When inspect the vehicle equipped with self-theft system, if the “replace the ECU” is listed in
the “Next steps” items, pay attention to programming ECU after replacement.

4. In this item: when P0171, P0172, P0335, P0336, P1651 occurs, the engine warning lamp
goes out.

5. If the DTC indicates one circuit has over low voltage, it means this circuit may be in short
circuit with the ground; if the DTC indicates one circuit has over high voltage, it means this
circuit may be in short circuit with the power; if the DTC indicates one circuit has circuit fault,
it means this circuit may be in open circuit or multiple faults may exist at the same time.

Diagnostic help:

1. If the DTC can not be erased, it means the malfunction is stable malfunction; check if the
connector is loosed if the malfunction is accidental malfunction.

2. No abnormality is found following the upper steps;

3. Do not neglect the influence of the vehicle maintenance, cylinder pressure, mechanism igni-
tion timing etc. during the inspection;

4. Do the test after replaced the ECU. If then the DTC can be erased, the malfunction exist in
ECU; if the DTC still existed, change back to use the original ECU and repeat the procedure
to make inspection again.\
4.1 DTC P0107: Intake air pressure sensor circuit voltage over low

No. Operation step Detection results Next step

Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Observe if the “intake air pressure” item of the data Yes Go to step 5
2 stream is about 101kpa (idiographic value according the
No Go to next step
actual air pressure).
Disconnect the intake air pressure sensor connector, use Yes Go to step 5
3 the multimeter to inspect if the voltage between connec-
No Go to next step
tor 3# and 1# is about 5V.
Check the harness wire between ECU terminal 40#, 19#, Repair or replace
Yes
4 59# and sensor connector 1#, 3#, 4# are open or short the harness wires
circuit with the ground No Go to next step
Start the engine, run at idle speed. Slowly step the accel- Yes Diagnostic help
erator pedal close to fully opening, observe the change
of “intake air pressure” item of diagnostic test, then the
5
display value should is not change a lot; quickly step the No Replace sensor
accelerator pedal close to fully opening, then the display
value should immediately to over then 90kpa.

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4.2 DTC P0108: Intake air pressure sensor circuit voltage over high

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Observe if the “intake air pressure” item of the data stream Yes Go to step 5
2 is about 101kpa (idiographic value according the actual air
No Go to next step
pressure).
Disconnect the intake air pressure sensor connector, use Yes Go to step 5
3 the multimeter to inspect if the voltage between connector
No Go to next step
3# and 1# is about 5V.
Check the harness wire between ECU terminal 40#, 19#, Repair or replace the har-
Yes
4 59# and sensor connector 1#, 3#, 4# are open or short cir- ness wires
cuit with the power. No Go to next step
Start the engine, run at idle speed. Slow step the accel- Yes Diagnostic help
erator pedal close to fully opening, observe the change of
“intake air pressure” item of diagnostic test, then the display
5
value should is not change a lot; quickly step the accel- No Replace sensor
erator pedal close to fully opening, then the display value
should immediately to over then 90kpa.

4.3 DTC P0112: Intake air temperature sensor indication temperature is over low

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Observe if the “intake air pressure” item of the data stream Yes Go to step 5
is same as the intake pipe temperature (idiographic value
2 according the actual engine temperature).
Notice: If the indication value is always -40°C, which No Go to next step
means maybe the open harness circuit occurred.
Disconnect the intake temperature sensor connector, use Yes Go to next step
the multimeter to inspect if the resistance between termi-
3
nal 3# and 1# is assort with the temperature(detail refer to No Replace sensor
the correlative parts of the repair manual).
Disconnect the intake temperature sensor connector, use Yes Go to step 5
4 the multimeter to check if the voltage between connecter
terminal 1# and 2# is about 5V. No Go to next step
Check if the harness wire between ECU (terminal 40#, Repair or replace the har-
Yes
5 19#) and the sensor connector (terminal 1#, 2#) is open or ness wires
short circuit with the power. No Go to next step
Start the engine, run at the idle speed. Observe the Yes Diagnostic help
change of “intake temperature” item, then the indication
6
value should increase with the raise of the engine intake No Replace sensor
temperature.

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4.4 DTC P0113: Intake temperature sensor indication temperature is over high

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Observe if the “intake air pressure” item of the data stream is Yes Go to step 5
same as the intake pipe temperature (idiographic value ac-
2 cording the actual engine temperature).
Notice: If the indication value is always -40°C, which means No Go to next step
maybe the open harness circuit occurred.
Disconnect the intake temperature sensor connector, use the Yes Go to next step
multimeter to inspect if the resistance between terminal 1#
3
and 2# is assort with the temperature(detail refer to the cor- No Replace sensor
relative parts of the repair manual).
Disconnect the intake temperature sensor connector, use the Yes Go to step 5
4 multimeter to check if the voltage between connecter termi-
nal 1# and 2# is about 5V. No Go to next step
Check if the harness wire between ECU (terminal 17#, 40#) Repair or replace the
Yes
5 and the sensor connector (terminal 1#, 2#) is open or short harness wires
circuit with the power. No Go to next step
Start the engine, run at the idle speed. Observe the change Yes Diagnostic help
of “intake temperature” item, and then the indication value
6
should increase with the raise of the engine intake tempera- No Replace sensor
ture.

4.5 DTC P0117: Engine coolant temperature sensor indication is over low

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Observe if the “coolant temperature” item of the data stream Yes Go to step 6
is same as the intake pipe temperature (idiographic value
2 according the actual engine temperature).
Notice: If the indication value is always -40°C, which means No Go to next step
maybe the open harness circuit occurred.
Disconnect the coolant temperature sensor connector, use Yes Go to next step
the multimeter to inspect if the resistance between terminal
3
1# and 3# is assort with the temperature(detail refer to the No Replace sensor
correlative parts of the repair manual).
Disconnect the coolant temperature sensor connector, use Yes Go to step 6
4 the multimeter to check if the voltage between connecter ter-
minal 1# and 3# is about 5V. No Go to next step
Check if the harness wire between ECU (terminal 40#, 41#) Repair or replace the
Yes
5 and the sensor connector (terminal1#, 3#) is open or short harness wires
circuit with the power. No Go to next step
Start the engine, run at the idle speed. Observe the change Yes Diagnostic help
of “coolant temperature” item, then the indication value
6
should increase with the raise of the engine intake tempera- No Replace sensor
ture.

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4.6 DTC P0118: Engine coolant temperature sensor indication is over high

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Observe if the “coolant temperature” item of the data stream Yes Go to step 6
is same as the intake pipe temperature (idiographic value ac-
2 cording the actual engine temperature).
Notice: If the indication value is always -40°C, which means No Go to next step
maybe the open harness circuit occurred.
Disconnect the coolant temperature sensor connector, use Yes Go to next step
the multimeter to inspect if the resistance between terminal
3
1# and 3# is assort with the temperature(detail refer to the No Replace sensor
correlative parts of the repair manual).
Disconnect the coolant temperature sensor connector, use Yes Go to step 6
4 the multimeter to check if the voltage between connecter ter-
minal 1# and 3# is about 5V. No Go to next step
Check if the harness wire between ECU (terminal 40#, 41#) Repair or replace the
Yes
5 and the sensor connector (terminal 1#, 3#) is open or short harness wires
circuit with the power. No Go to next step
Start the engine, run at the idle speed. Observe the change of Yes Diagnostic help
6 “coolant temperature” item, then the indication value should
increase with the raise of the engine intake temperature. No Replace sensor

4.7 DTC P0122: Throttle position sensor circuit voltage is over low

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Observe if the “throttle absolute opening” item of the data Yes Go to next step
2 stream is between 4%-10% (Detail value is different accord-
ing to the vehicle type) No Go to step 5
Step the accelerator pedal to fully opening slowly, observe Yes Go to next step
the value of the data stream “throttle absolute opening” item
3 is increase to between 85-95% with the throttle opening in-
creasing. (detail value is different according to the vehicle No Go to step 5
type)
Repeat the step 3, observe if the value of the data steam Yes Replace sensor
4
“throttle absolute opening” item is jumping changed. No Go to next step
Disconnect the throttle position sensor connector, check if the Repair or replace the
Yes
harness wire between ECU (terminal 18#, 39#, 26# )and the harness wires
5
sensor connector (terminal 1#, 2#, 3#) is short circuit with the
No Go to next step
ground
Use multimeter to check if the voltage between this connec- Yes Replace sensor
6
tor terminal 1# and 2# is about 5V. No Diagnostic help

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4.8 DTC P0123: Throttle position sensor circuit voltage is over high

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Observe if the value of data steam “throttle absolute open- Yes Go to next step
2 ing” is between 4%-10% (detail value is according to the
vehicle type). No Go to step 5
Step the accelerator pedal to fully opening slowly, observe Yes Go to next step
the value of the data stream “throttle absolute opening”
3 item is increase to between 85-95% with the throttle open-
ing increasing. (detail value is different according to the No Go to step 5
vehicle type)

Repeat the step 3, observe if the value of the data steam Yes Replace sensor
4
“throttle absolute opening” item is jumping changed. No Go to next step
Disconnect the throttle position sensor connector, check Repair or replace the
Yes
if the harness wire between ECU (terminal 17#, 32#, 16#) harness wires
5
and the sensor connector (terminal 1#, 2#, 3#) is open or
short circuit with the ground. No Go to next step

Use multimeter to check if the voltage between this con- Yes Replace sensor
6
nector terminal 1# and 2# is about 5V. No Diagnostic help

4.9 DTC P0130: Front oxygen sensor signal circuit failed

(Remark: The procedure is accord with the no DTC P0135, if the DTC P0135 existed at the same
time, should first deal with the malfunction P0135, then check as the follow procedure.)

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Start the engine, run at idle speed until the coolant tem- Yes Diagnostic help
perature to the normal value. Observe the value change
2
of diagnostic test “oxygen sensor voltage” item, the value No Go to next step
should change quickly between 100mV~900mV.
Check if the harness wire between ECU (terminal 2#, Repair or replace the
Yes
3 39#, 45#) and the sensor connector (terminal2#, 3#, 4#) harness wires
is short circuit with the ground. No Go to next step
(A) Check if the serious air leakage in the intake air sys- Check and repair based
Yes
tem; on the diagnosis
(B) If the injector is blocked;
4 (C) If the spark plug clearance is too large;
(D) If the high tension line resistance is too high; No Diagnostic help
(E) The abrasion of intake valve guide pipe;
Etc.

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4.10 DTC P0132: Front oxygen sensor circuit voltage over high

(Remark: The procedure is accord with the no DTC P0135, if the DTC P0135 existed at the same
time, should first deal with the malfunction P0135, then check as the follow procedure.)

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “ON”.
Start the engine, run at idle speed until the coolant temperature Yes Diagnostic help
to the normal value. Observe the value change of diagnostic test
2
“oxygen sensor voltage” item, the value should change quickly No Go to next step
between 100mV~900mV.
Check if the harness wire between ECU (terminal 2#, 39#, 45#) Repair or replace
Yes
3 and the sensor connector (terminal2#, 3#, 4#) is short circuit with the harness wires
the ground. No Diagnostic help

4.11 DTC P0134: Malfunction of the front oxygen sensor signal

(Remark: The procedure is accord with the no DTC P0135, if the DTC P0135 existed at the same
time, should first deal with the malfunction P0135, then check as the follow procedure.)

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “ON”.
Start the engine, run at idle speed until the coolant temperature
Yes Diagnostic help
to the normal value. Observe the value change of diagnostic test
2
“oxygen sensor voltage” item, the value should change quickly
between 100mV~900mV. No Go to next step

Check if the harness wire between ECU (terminal 2#, 39#, 45#) Repair or replace
Yes
3 and the sensor connector (terminal2#, 3#, 4#) is short circuit with the harness wires
the ground. No Diagnostic help

4.12 DTC P0135: Malfunction of the front oxygen sensor heater

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “ON”.
Remove the front oxygen sensor connector, use multimeter to Yes Go to next step
check if the voltage between the connector C# (correspond to
2
the white line of oxygen sensor) and D# (correspond to the white No Go to step 4
line of oxygen sensor) is about 12V.
Use multimeter to check if the resistance between oxygen sen- Yes Go to next step
3
sor pin C# (white) and D# (white) is between 2~5Ω under 20°C. No Replace sensor

Check if the 8A fuse of oxygen sensor heat circuit has been fus- Yes Replace fuse
4
ing. No Go to next step
Check if the harness wire between ECU (terminal 1#), main re- Repair or replace
Yes
lay (pin 87#) and oxygen sensor connector pin C# (correspond the harness wires
5 to the white line of oxygen sensor), D# (correspond to the white
line of oxygen sensor) is open circuit or short circuit with the No Diagnostic help
power or the ground.

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4.13 DTC P0171: Air/fuel ratio closed-loop control self-adaptive over upper limit

(Remark: The procedure is accord with the no DTC for intake air pressure sensor, canister control
valve, oxygen sensor etc. if the DTCs existed at the same time, should first deal with these mal-
function, then check as the follow procedure.)

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch to
1 Go to next step
“ON”.
Start the engine, run at idle speed until the coolant temperature to Yes Go to next step
the normal temperature.
2 With fully load, Observe the change value of diagnostic test “oxygen
sensor voltage” item, then if the value maintain near the 100mV for No Diagnostic help
a long time at the certain load.
Yes Go to next step
Connect the fuel pressure gauge at the fuel inlet pipe, Observe if
3 Check the fuel
the fuel pressure maintain at about 350kPa with fully load. No
system
Check if the harness wire between ECU (terminal 2#, 39#, 45#) and Repair or replace
Yes
4 the sensor connector (terminal 2#, 3#, 4#) is short circuit with the the harness wires
ground. No Go to next step
A. Check if the serious air leakage in the intake air system; Repair based
Yes
B. If the injector is blocked; on the diagnostic
C. If the spark plug clearance is too large;
5
D. If the high tension line resistance is too high;
No Diagnostic help
E. The abrasion of intake valve guide pipe;
Etc.

4.14 DTC P0172: Air/fuel ratio closed-loop control self-adaptive over lower limit

(Remark: The procedure is accord with the no DTC for intake air pressure sensor, canister control
valve, oxygen sensor etc. if the DTCs existed at the same time, should first deal with these mal-
function, then check as the follow procedure.)

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch to
1 Go to next step
“ON”.
Start the engine, run at idle speed until the coolant temperature to Yes Go to next step
the normal temperature.
2 With fully load, Observe the change value of diagnostic test “oxygen
sensor voltage” item, then if the value maintain near the 100mV for No Diagnostic help
a long time at the certain load.
Yes Go to next step
Connect the fuel pressure gauge at the fuel inlet pipe, Observe if
3 Check the fuel
the fuel pressure maintain at about 350kPa with fully load. No
system
Check if the harness wire between ECU (terminal 2#, 39#, 45#) Repair or replace
Yes
4 and the sensor connector (terminal2#, 3#, 4#) is short circuit with the harness wires
the ground. No Go to next step
A. If the injector leaked; Repair based
Yes
B. The exhaust pipe leakage; on the diagnostic
5
C. The improper ignition timing;
No Diagnostic help
Etc.

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4.15 DTC P0201: Malfunction of cylinder 1 injector

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Remove the cylinder 1 injector connector, use multimeter to Yes Go to step 4
2 check if the voltage between this connector (terminal 1#) and
the power negative pole is about 12V. No Go to next step
Check if the harness wire between cylinder 1 injector (termi- Repair or replace
Yes
3 nal 1#) and main relay is open circuit or short circuit with the the harness wires
ground No Go to next step

Use multimeter to check if the resistance between cylinder 1 Yes Go to next step
4
injector terminal 1# and 2# is between 11~13Ω under 20°C. No Replace injector
Use multimeter to check the voltage between cylinder 1 in- Yes Diagnostic help
5 jector connector terminal 2# and the power negative pole is
about 3.7V. No Go to next step
Check if the harness wire between cylinder 1 injector terminal Repair or replace
Yes
6 2# and ECU terminal 50# is open circuit or short circuit with the harness wires
the power or the ground No Diagnostic help

4.16 DTC P0202: Malfunction of the cylinder 2 injector circuit

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Remove the cylinder 2 injector connector, use multimeter to Yes Go to step 4
2 check if the voltage between this connector (terminal 1#) and
the power negative pole is about 12V. No Go to next step
Check if the harness wire between cylinder 2 injector (termi- Repair or replace
Yes
3 nal 1#) and main relay is open circuit or short circuit with the the harness wires
ground No Go to next step

Use multimeter to check if the resistance between cylinder 2 Yes Go to next step
4
injector terminal 1# and 2# is between 11~13Ω under 20°C. No Replace injector
Use multimeter to check the voltage between cylinder 2 in- Yes Diagnostic help
5 jector connector terminal 2# and the power negative pole is
about 3.7V. No Go to next step
Check if the harness wire between cylinder 2 injector termi- Repair or replace
Yes
6 nal 2# and ECU terminal 63# is open circuit or short circuit the harness wires
with the power or the ground No Diagnostic help

4.17 DTC P0203: Malfunction of the cylinder 3 injector circuit

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 BYD S6, S6A, S6K Service Manual

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “ON”.
Remove the cylinder 3 injector connector, use multimeter to Yes Go to step 4
2 check if the voltage between this connector (terminal 1#) and the
power negative pole is about 12V. No Go to next step
Check if the harness wire between cylinder 3 injector connector Repair or replace
Yes
3 (terminal 1#) and main relay is open circuit or short circuit with the harness wires
the ground No Go to next step

Use multimeter to check if the resistance between cylinder 3 in- Yes Go to next step
4
jector terminal 1# and 2# is between 11~13Ω under 20°C. No Replace injector

Use multimeter to check the voltage between cylinder 3 injector Yes Diagnostic help
5
connector terminal 2# and the power negative pole is about 3.7V. No Go to next step
Check if the harness wire between cylinder 3 injector terminal Repair or replace
Yes
6 2# and ECU terminal 49# is open circuit or short circuit with the the harness wires
power or the ground No Diagnostic help

4.18 DTC P0204: Malfunction of the cylinder 4 injector circuit

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “ON”.
Remove the cylinder 4 injector connector, use multimeter to Yes Go to step 4
2 check if the voltage between this connector (terminal 1#) and
the power negative pole is about 12V. No Go to next step
Check if the harness wire between cylinder 4 injector connector Repair or replace
Yes
3 (terminal 1#) and main relay is open circuit or short circuit with the harness wires
the ground No Go to next step

Use multimeter to check if the resistance between cylinder 4 in- Yes Go to next step
4
jector terminal 1# and 2# is between 11~13Ω under 20°C. No Replace injector

Use multimeter to check the voltage between cylinder 4 injector Yes Diagnostic help
5
connector terminal 2# and the power negative pole is about 3.7V. No Go to next step
Check if the harness wire between cylinder 3 injector terminal
Repair or replace
6 2# and ECU terminal 64# is open circuit or short circuit with the Yes
the harness wires
power or the ground

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4.19 DTC P0230: Malfunction of the fuel pump control circuit

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “OFF”.
Remove the fuel pump relay, turn the ignition switch to Yes Go to step 4
”ON”, check if the voltage between fuel pump relay power
2
terminal (terminal 30#, 86#) and the power negative pole is No Go to next step
about 12V.
Repair or replace the
Check if the relay power terminal harness circuit is open or Yes
3 harness wires
short circuit with the ground
No Go to step 2
Use multimeter to check if the voltage between fuel pump Yes Replace the fuel relay
4 relay control terminal (terminal 85#) and the power nega-
tive pole is about 3.7V. No Go to next step
Check if the harness wire between relay control terminal Repair or replace the
Yes
5 (terminal 85#) and the ECU terminal 60# is open or short harness wires
circuit with the power or the ground. No Diagnostic help

4.20 DTC P0325: Malfunction of the knock sensor circuit

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “OFF”.
Remove the knock sensor connector, use multimeter to Yes Go to next step
2 check if the voltage between the knock sensor terminal 1#
No Replace sensor
and 2# is more than 1MΩ.
Check if the harness wire between knock sensor connector Repair or replace the
Yes
3 (terminal 1#, 2#) and ECU (terminal 30#, 31#) is open or harness wires
short circuit with the power or the ground No Go to next step
Replace the knock sensor according the specification, start Yes Diagnostic help
4 the engine and accelerate to 2200 r/min. check if the DTC
P0325 occurs again. No Check if accidental

4.21 DTC P0335: Malfunction of the crankshaft position sensor signal

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “OFF”.
Remove the Rotating Speed Sensor connector, use multi- Yes Go to next step
2 meter to check if the voltage between rotating speed sensor
terminal 2# and 3# is between 770~950Ω under 20°C. No Replace sensor
Check if the harness wire between rotating speed sensor Repair or replace the
Yes
3 connector (terminal 2#, 3#) and the ECU (terminal 47#, 46#) harness wires
is open or short circuit with the power or the ground No Go to next step
Yes Diagnostic help
4 Check if the flywheel signal disc is right.
No Replace the signal disc

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4.22 DTC P0336: Malfunction of the crankshaft position sensor signal illogicality

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “OFF”.
Remove the Rotating Speed Sensor connector, use multimeter Yes Go to next step
2 to check if the voltage between rotating speed sensor terminal
2# and 3# is between 770~950Ω under 20°C. No Replace sensor
Check if the harness wire between rotating speed sensor con- Repair or replace
Yes
3 nector (terminal 1#, 2#) and the ECU (terminal 39#, 42#) is the harness wires
open or short circuit with the power or the ground No Go to next step
Yes Diagnostic help
4 Check if the flywheel signal disc is right. Replace the signal
No
disc

4.23 DTC P0340: Malfunction of the phase sensor signal

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Remove the phase sensor connector, use multimeter to check Yes Go to step 4
2 if the voltage between phase sensor terminal 1# and 3# is
about 12V No Go to next step
Check if the harness wire between the phase sensor 3# Repair or replace the
Yes
and main relay terminal 87# is open or short circuit with the harness wires
3 ground.
Check if the phase sensor terminal 1# is poor contact with the No Go to next step
ground
Check if the voltage between phase sensor 2# and the power Yes Go to step 6
4
negative pole is about 9.9V. No Go to next step
Check if the harness wire between phase sensor connector Repair or replace the
Yes
5 terminal 2# and the ECU terminal 42# is open or short circuit harness wires
with the power or the ground No Go to next step
Yes Diagnostic help
6 Check if the camshaft signal disc is right Replace the signal
No
disc

4.24 DTC P0342: Phase sensor circuit voltage over low

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Remove the phase sensor connector, use multimeter to check Yes Go to step 4
2 if the voltage between phase sensor terminal 1# and 3# is
about 12V No Go to next step
Check if the harness wire between the phase sensor 3# Repair or replace the
Yes
and main relay terminal 87# is open or short circuit with the harness wires
3 ground.
Check if the phase sensor terminal 1# is poor contact with the No Go to next step
ground
Check if the voltage between phase sensor 2# and the power Yes Go to step 6
4
negative pole is about 9.9V. No Go to next step

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Detection
No. Operation step Next step
results
Check if the harness wire between phase sensor connector Repair or replace the
Yes
5 terminal 2# and the ECU terminal 42# is open or short circuit harness wires
with the power or the ground No Go to next step
Yes Diagnostic help
6 Check if the camshaft signal disc is right Replace the signal
No
disc

4.25 DTC P0343: Phase sensor circuit voltage over high

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “ON”.
Remove the phase sensor connector, use multimeter to check Yes Go to step 4
2 if the voltage between phase sensor terminal 1# and 3# is
about 12V No Go to next step
Check if the harness wire between the phase sensor 3# and Repair or replace the
Yes
main relay terminal 87# is open or short circuit with the ground. harness wires
3
Check if the phase sensor terminal 1# is poor contact with the
No Go to next step
ground
Check if the voltage between phase sensor 2# and the power Yes Go to step 6
4
negative pole is about 9.9V. No Go to next step
Check if the harness wire between phase sensor connector Repair or replace the
Yes
terminal 2# and the ECU terminal 42# is open or short circuit harness wires
5
with th
No Go to next step
e power or the ground
Yes Diagnostic help
6 Check if the camshaft signal disc is right Replace the signal
No
disc

4.26 DTC P0443: Canister control valve driving control circuit malfunction

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “ON”.
Remove the canister control valve connector, use multimeter Yes Go to step 4
2 to check if the voltage between this connector terminal 1# and
the power negative pole is about 12V No Go to next step
Repair or replace the
Check if the canister control valve power terminal circuit is Yes
3 harness wires
open or short circuit with the ground
No Go to step 2
Use multimeter to check if the resistance between canister Yes Go to next step
4 control valve terminal 1# and 2# is between 22~30Ω under Replace the
20°C. No
control valve
Use multimeter to check if the voltage between canister control Yes Diagnostic help
5 valve connector terminal 1# and the power negative pole is
about 3.7V. No Go to next step
Repair or replace the
Check if the harness wire between canister control valve con- Yes
6 harness wires
nector terminal 2# and the ECU terminal 37# is open circuit.
No Diagnostic help

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4.27 DTC P0444: Canister control valve driving control circuit voltage over low

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “ON”.
Remove the canister control valve connector, use multimeter to Yes Go to step 4
2 check if the voltage between this connector terminal 1# and the
power negative pole is about 12V No Go to next step
Repair or replace the
Check if the canister control valve power terminal circuit is Yes
3 harness wires
open or short circuit with the ground
No Go to step 2
Yes Go to next step
Use multimeter to check if the resistance between canister con-
4 Replace the
trol valve terminal 1# and 2# is between 22~30Ω under 20°C. No
control valve
Use multimeter to check if the voltage between canister control Yes Diagnostic help
5 valve connector terminal 1# and the power negative pole is
about 3.7V. No Go to next step
Check if the harness wire between canister control valve con- Repair or replace the
Yes
6 nector terminal 2# and the ECU terminal 37# is short circuit harness wires
with the ground No Diagnostic help

4.28 DTC P0445: Canister control valve driving control circuit voltage over high

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “ON”.
Remove the canister control valve connector, use multimeter to Yes Go to step 4
2 check if the voltage between this connector terminal 1# and the
power negative pole is about 12V No Go to next step
Repair or replace the
Check if the canister control valve power terminal circuit is open Yes
3 harness wires
or short circuit with the ground
No Go to step 2
Yes Go to next step
Use multimeter to check if the resistance between canister con-
4 Replace the
trol valve terminal 1# and 2# is between 22~30Ω under 20°C. No
control valve
Use multimeter to check if the voltage between canister control Yes Diagnostic help
5 valve connector terminal 1# and the power negative pole is
about 3.7V. No Go to next step
Check if the harness wire between canister control valve con- Repair or replace the
Yes
6 nector terminal 2# and the ECU terminal 37# is short circuit with harness wires
the power No Diagnostic help

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4.29 DTC P0480: Malfunction of the A/C condenser cooling fan relay control circuit

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “OFF”.
Remove the A/C condensator cooling fan relay, turn the Yes Go to step 4
2 ignition switch to “ON”, check if the voltage between this
relay power terminal 30# and 85# is about 12V. No Go to next step
Check if the harness wire of A/C condensator cooling Repair or replace the
Yes
3 fan relay power terminal is open or short circuit with the harness wires
ground. No Go to step 2
Use multimeter to check if the voltage between A/C con- Replace the
Yes
4 densator cooling fan relay control terminal 86# and the relay
power negative pole is about 3.7V. No Go to next step
Check if the harness wire between relay control terminal Repair or replace the
Yes
5 86# and ECU terminal 62# is open circuit or short circuit harness wires
with the power or the ground No Diagnostic help

4.30 DTC P0500: Malfunction of the vehicle speed

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “OFF”.
Check and repair the
If the vehicle required with ABS system, check if the DTC Yes
2 ABS system
exists at the ABS system.
No Go to next step
Yes Go to next step
3 Check if the work of the speedometer finger is normal. Check the speedometer
No
circuit
Yes Go to next step
4 Check if the work of the vehicle speed sensor is normal. Replace the speed sen-
No
sor
Check if the harness wire between vehicle speed sensor Repair or replace the
Yes
4 signal wire and the ECU terminal 11# is open circuit or harness wires
short circuit for the power or the ground. No Diagnostic help

4.31 DTC P0506: Idle speed lower than target idle speed

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “OFF”.
Yes Go to next step
Check if the throttle adjusting bolt, throttle valve cable,
2 Make necessary check
and throttle work well. No
and repair, maintenance
Yes Go to next step
3 Check if the idle speed adjustor work well Make necessary check
No
and repair, maintenance
A. Check if the pressure of fuel supply system is too low; Make necessary check
Yes
4 B. Check if the injector is blocked; and repair
C. Check if the exhaust is not smooth No Diagnostic help

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4.32 DTC P0507: Idle speed higher than target idle speed

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the
1 Go to next step
ignition switch to “OFF”.
Yes Go to next step
Check if the throttle adjusting bolt, throttle valve
2 Make necessary check and repair,
cable, throttle work well. No
maintenance
Yes Go to next step
3 Check if the idle speed adjustor work well Make necessary check and repair,
No
maintenance
A. Check if the pressure of fuel supply system is Yes Make necessary check and repair
too low;
4
B. Check if the injector is blocked; No Diagnostic help
C. Check if the exhaust is not smooth

4.33 DTC P0508: Idle adjustor control circuit voltage over low

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn
1 Go to next step
the ignition switch to “ON”.
Remove the idle adjustor connector, use multi- Yes Go to next step
meter to check if the resistance between termi-
2
nal 1 and 4, 2 and 3 of the idle adjustor is about No Replace the step motor
53 ± 5.3Ω under 20°C.
Separately check if the harness wire between Repair or replace the harness
Yes
idle speed adjustor connector (terminal 1, 2, wires
3
3, 4) and ECU (terminal 36#, 35#, 21#, 22#) is
No Diagnostic help
short circuit with the ground.

4.34 DTC P0509: Idle speed adjustor control circuit voltage over high

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn
1 Go to next step
the ignition switch to “ON”.
Remove the idle adjustor connector, use mul- Yes Go to next step
timeter to check if the resistance between
2
terminal1 and 4, 2 and 3 of the idle adjustor is No Replace the step motor
about 53 ± 5.3Ω under 20°C.
Separately check if the harness wire between Repair or replace the harness
Yes
idle speed adjustor connector (terminal 1, 2, wires
3
3, 4) and ECU (terminal36#, 35#, 21#, 22#) is
No Diagnostic help
short circuit with the ground.

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4.35 DTC P0511: Malfunction of the idle speed adjustor control circuit

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “ON”.
Remove the idle adjustor connector, use multimeter to check if Yes Go to next step
2 the resistance between terminal 1 and 4, 2 and 3 of the idle ad- Replace the step
justor is about 53 ± 5.3Ω under 20°C. No
motor
Separately check if the harness wire between idle speed adjus- Repair or replace the
Yes
3 tor connector (terminal A, B, C, D) and ECU (terminal 36#, 35#, harness wires
21#, 22#) is open circuit with the ground. No Diagnostic help

4.36 DTC P0560: System voltage signal illogicality

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “OFF”.
Yes Go to next step
2 Use multimeter to check if the battery voltage is about 12V.
No Replace the battery
Check if the harness wire between ECU (terminal 16#, 32#) Repair or replace the
Yes
3 and main relay terminal 87# is open circuit or short circuit with harness wires
the ground. No Go to next step
Yes Go to next step
Start the engine, check if the charging voltage of generator is
4 Replace the genera-
always between 9-16V during different rotating speed. No
tor
Yes Diagnostic help
5 Check if the ground wire of engine harness is fine. Repair or replace the
No
harness wires

4.37 DTC P0562: System voltage over low

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition switch
1 Go to next step
to “OFF”.
Yes Go to next step
2 Use multimeter to check if the battery voltage is about 12V.
No Replace the battery
Repair or replace the
Check if the harness wire resistance between ECU (terminal Yes
3 harness wires
16#, 32#) and main relay terminal 87# is too high.
No Go to next step
Yes Go to next step
Start the engine, check if the charging voltage of generator is
4 Replace the genera-
always between 9-16V during different rotating speed. No
tor
Yes Diagnostic help
5 Check if the ground wire of engine harness is fine. Repair or replace the
No
harness wires

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4.38 DTC P0563: System voltage over high

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “OFF”.
Yes Go to next step
2 Use multimeter to check if the battery voltage is about 12V.
No Replace the battery

Start the engine, check if the charging voltage of generator is Yes Go to next step
3
always between 9-16V during different rotating speed. No Replace the generator
Yes Diagnostic help
4 Check if the ground wire of engine harness is fine. Repair or replace the
No
harness wires

4.39 DTC P0601: ECU check code failure

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Erase the DTC, ensure if the malfunction is stable malfunc- Yes Go to next step
2
tion. No System is normal
3 Replace the ECU. End

4.40 DTC P0602: ECU diagnostic data identification code failure

Detection
No. Operation step Next step
results
Connect the diagnostic and the adapter, turn the ignition
1 Go to next step
switch to “ON”.
Erase the DTC, ensure if the malfunction is stable malfunc- Yes Go to next step
2
tion. No System is normal
3 Replace the ECU. End

4.41 DTC:P0645 Malfunction of air conditioner compressor relay control circuit\

Detection
No. Operation Steps Next step
results
Connect the diagnosis tester and the adapter, turn the igni-
1 Go to next step
tion switch to ‘ON”.

Remove air conditioner compressor relay, turn the ignition Yes Go to step 4
switch to “ON”, and check relay supply end. Check if the
2
voltage between the relay30#and 85#plug and power nega-
tive electrode is about 12V. No Go to next step

Repair or replace the

Check if the relay supply end harness wire is open circuit or Yes
3 harness wires
short circuit with the ground.
No Go to step 2
Check air conditioner compressor relay control end with the Yes Replace relay
4 multimeter. Check if the voltage between the relay 86# plug
No Go to next step
and power negative electrode is about 3.7V

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Detection
No. Operation Steps Next step
results
Check air conditioner compressor relay control end. Check Repair or replace the
Yes
5 if the harness wire between the relay terminal 86#and ECU harness wires
terminal 70# is open circuit. No Diagnosis help

4.42 DTC: P0646 Air conditioner compressor relay control circuit voltage over low

Detection
No. Operation Steps Next step
results
Connect the diagnosis tester and the adapter, turn the igni-
1 Go to next step
tion switch to “OFF”.

Remove air conditioner compressor relay, turn the ignition Yes Go to step 4
switch to “ON”, and check relay supply end. Check if the
2
voltage value between the relay pin 30#and 85# and power
negative electrode is about 12V No Go to next step

Repair or replace the

Check relay supply end harness wire is open circuit or short Yes
3 harness wires
circuit with the ground.
No Go to next step
Check air conditioner compressor relay control end with the Yes Replace relay
4 multimeter. Check if the voltage value between the relay pin
No Go to next step
86# and power negative electrode is about 3.7V
Check air conditioner compressor relay control end .Check if Repair or replace the
Yes
5 the harness wire between the relay 86 pin and ECU terminal harness wires
70 is short circuit with the ground. No Go to next step
Yes Diagnosis help
Check if air conditioner compressor electromagnetic clutch
6 Repair or replace the
is fine. No
electromagnetic clutch

4.43 DTC: P0647 Air conditioner compressor relay control circuit voltage over high

Detection
No. Operation Steps Next step
results
Connect the diagnosis tester and the adapter, turn the igni-
1 Go to next step
tion switch to “OFF”.
Remove air conditioner compressor relay, turn the ignition Yes Go to step 4
switch to “ON”, and check relay supply end. Check if the
2
voltage value between the relay pin 30#and 85# and power No Go to next step
negative electrode is about 12V
Repair or replace the
Check relay supply end harness wire is open circuit or short Yes
3 harness wires
circuit with the ground.
No Go to step 2
Check air conditioner compressor relay control end with the Yes Replace relay
multimeter. Check if the voltage value between the harness
4
wire between the relay 86 pin and power negative electrode No Go to next step
is about 3.7V.
Check air conditioner compressor relay contrail end. Check Repair or replace the
Yes
5 if the harness wire between the relay pin 86#and ECU ter- harness wires
minal 70# is short circuit with the ground. No Go to next step
Yes Diagnosis help
Check if air conditioner compressor electromagnetic clutch
6 Repair or replace the
is fine. No
electromagnetic clutch

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4.44 DTC: P0507 Idle target idle voltage over high

Detection
No. Operation Steps Next step
results
Connect the diagnosis tester and the adapter, turn the igni-
1 Go to next step
tion switch to “ON”.
Remove idle adjustor EWD connector on the harness wire, Yes Go to step 4
and check if the voltage value between the connector termi-
2
nal 2# and the power negative electrode is about 12V with No Go to next step
the multimeter.
Repair or replace the
Check if the harness wire of the idle adjustor EWD supply Yes
3 harness wires
end is open or short circuit with the ground.
No Go to next step
Check if the resistance between the terminal 3#and 2# of Yes Go to next step
4 idle adjustor EWD is about 15.5Ω under 20°C with the mul-
timeter No Replace EWD
Check if the harness wire between the idle adjustor EWD Repair or replace the
Yes
5 connector terminal 3# and ECU terminal 29# is short circuit harness wires
with the ground. No Diagnosis help

4.45 DTC: P0506 Idle target idle voltage over low

Detection
No. Operation Steps Next step
results
Connect the diagnosis tester and the adapter, turn the igni-
1 Go to next step
tion switch to ‘ON”.
Remove idle adjustor EWD connector on the harness wire, Yes Go to step 4
and check if the voltage value between the connector termi-
2
nal 2# and the power negative electrode is about 12V with No Go to next step
the multimeter.
Repair or replace the
Check if the harness wire of the idle adjustor EWD supply Yes
3 harness wires
end is open or short circuit with the ground.
No Go to next step
Check if the resistance between the terminal 1#and 2# of Yes Go to next step
4 idle adjustor EWD is about 17.6Ωunder 20°C with the multi-
meter. No Replace EWD
Check if the harness wire between the idle adjustor EWD Repair or replace the
Yes
5 connector terminal 1# and ECU terminal 26# is open circuit harness wires
or short circuit with the ground. No Diagnosis help

4.46 DTC: P0509 Idle adjustor control circuit voltage over high

Detection
No. Operation Steps Next step
results
Connect the diagnosis tester and the adapter, turn the igni-
1 Go to next step
tion switch to “ON”.
Remove idle adjustor EWD connector on the harness wire, Yes Go to step 4
and check if the voltage value between the connector termi-
2
nal 2# and the power negative electrode is about 12V with No Go to next step
the multimeter.
Repair or replace the
Check if the harness wire of the idle adjustor EWD supply Yes
3 harness wires
end is open circuit or short circuit with the ground.
No Go to next step
Check if the resistance between the terminal 1#and 2# of Yes Go to next step
4 idle adjustor EWD is about 17.6Ωunder 20°C with the multi-
meter. No Replace EWD

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Detection
No. Operation Steps Next step
results
Check if the harness wire between the idle adjustor EWD Repair or replace the
Yes
5 connector terminal 1# and ECU terminal 26# is short circuit harness wires
with the power. No Diagnosis help

4.47 DTC P1651: Malfunction of the SVS control circuit

Detection
No. Operation Steps Next step
results
Connect the diagnosis tester and the adapter, turn the igni-
1 Go to next step
tion switch to “ON”.
Use the “actuator action test” item of diagnostic test to make Yes Go to next step
2 the action test for the SVS, detect that if it always is OFF or
ON.. No System is normal
Repair or replace the
Check the SVS power terminal harness wire is open circuit Yes
3 harness wires
or short circuit with the ground.
No Go to next step
Check if the harness wire between SVS control terminal and Repair or replace the
Yes
4 the ECU (terminal 28#) is open or short circuit for the power harness wires
supply or the ground. No Go to next step
Yes Diagnosis help
5 Check if the SVS bulb is normal.
No Replace the bulb

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5. Diagnostic procedure of M7 system according to fault phenomenon

Before diagnosis according to engine malfunction symptom, you should make a first inspection:

1. Ensure engine malfunction indicator normally work;

2. Ensure there is no malfunction record with diagnostic tester;

3. Ensure the symptom that host complaints exists, and ensure the condition that cause the
malfunction.

Appearance inspection:

(1) Check whether the fuel pipeline has the symptom of leakage;

(2) Check whether vacuum pipeline has the symptom of rupture, twist and bad connection;

(3) Check whether the intake pipeline has the symptom of jam, leakage, staved or hurt;

(4) Check whether high tension cable of ignition system has the symptom of rupture, aging and
wrong ignition sequence;

(5) Check whether the position of wire harness grounding is clean and reliable;

(6) Check whether the sensors and actuator connector has the symptom of loose or bad con-
tact.

NOTICE
If the above symptom exists, first make
maintenance in accordance with the
malfunction, or the repair and diagnosis
will be affected.

Diagnosis:
1. ensure there is no malfunction record;

2. ensure the malfunction symptom that is complained exists;

3. has finished the above inspection, and don’t find abnormal condition;

4. don’t overlook the influence that is caused by the condition such as vehicle mainte-
nance condition, cylinder pressure, mechanism ignition timing and fuel condition in
the repair process;

5. Replace ECU, and test it.

If the malfunction symptom can be cleared, malfunction exists in ECU. If malfunction symptom
still exists, replace back the original ECU, and repeat inspection procedure again.

A. Engine does not rotate or rotates slowly when starting;

B. Engine can rotate but starting fails when starting;

C. Hot engine starting has difficulty;

D. Cold engine starting has difficulty;

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E. Engine speed is normal but starting has difficulty at any time;

F. Starting is normal but idle speed is not stable at any time;

G. Starting is normal but idle speed is not stable in warming up;

H. Starting is normal but idle speed is not stable after warming up;

I. Starting is normal but under partial load (for example, A/C is on) idle speed is not stable or
engine stalls;

J. Starting is normal but idle speed is high;

K. Engine speed can not increase smoothly or stalls;

L. Slow response in acceleration;

M. Poor performance in acceleration.

5.1 When starting, engine can’t work or work slowly

Common position for malfunction: 1. battery; 2. starter; 3. wire harness or ignition switch; 4. en-
gine mechanism part

Common diagnostic procedure:

Serial Test
Operation step Continuous step
NO. result
Check the voltage between both electrode with multi- Yes Next step
1 meter, when engine starts, whether the voltage is about
8-12V. No Replace battery
Keep the ignition switch on starting position, check Yes Next step
2 whether the anode of starter is over 8V with multi- Repair or replace wire har-
meter. No
ness
Remove starter, and check its work condition. the point Yes Repair or replace starter
3 is to check whether there is the symptom of open cir-
cuit or locked for bad lubrication. No Next step

If the malfunction happens only in winter. Check wheth- Yes Replace proper lubrication oil
4
er the engine lubrication oil and gear oil is proper. No Next step
Check whether the reason that starter doesn’t work or Repair engine inner resis-
Yes
5 rotate slowly is the over-high engine inner mechanical tance
resistance. No Diagnosis

5.2 When starting, starter works but engine doesn’t work

Common diagnostic position: 1. no fuel in fuel tank; 2. fuel pump; 3. rotate speed sensor; 4. igni-
tion coil; 5. engine mechanical part

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Common diagnostic procedure:

Serial
Operation step Test result Continuous step
NO.
Connect fuel pressure meter (connecting position is front Yes Next step
1 end of inlet pipe of fuel distribution pipe assembly), start Repair supply fuel sys-
engine, check whether fuel pressure is about 350kPa. No
tem
Connect diagnostic tester of electronic injection system, Yes Next step
2 observe the data of “engine rotate speed”, start engine Repair circuitry of rotate
and observe whether there is rotation speed signal output. No
speed sensor
Pull out high tension cable of a cylinder, connect spark Yes Next step
plug, make the distance from spark plug electrode to en-
3
gine body is about 5mm, start engine and check whether No Repair ignition system
there is the white-blue high tension fire.
Exclude engine me-
Check the pressure condition of each cylinder and ob- Yes
4 chanical malfunction
serve whether there is the symptom of pressure shortage.
No Next step
Connect adapter of electronic injection system, open igni- Yes Diagnosis
tion switch, check whether power supply of 64#, 49#, 50#,
5
63# pin is normal; check whether grounding of 43#, 48#, No Repair related circuitry
5# pin is normal.

5.3 When warming up engine, hard start.

Common malfunction position: 1. there is water in fuel; 2. fuel pump; 3. coolant temperature sen-
sor; 4. fuel pressure adjuster vacuum pipe; 5. ignition coil

Common diagnostic procedure:

Serial
Operation step Test result Continuous step
NO.
Connect fuel pressure meter (connecting position is
Yes Next step
front end of inlet pipe of fuel distribution pipe assembly),
1
start engine, and check whether fuel pressure is about Repair supply fuel sys-
No
350kPa. tem
Pull out high tension cable of a cylinder, connect spark Yes Next step
plug, make the distance from spark plug electrode to en-
2
gine body is about 5mm, start engine and check whether
No Repair ignition system
there is the white-blue high tension fire.
Pull out connector of coolant temperature sensor, start Repair circuit or replace
Yes
engine, and observe whether engine can start. (serially sensor
3 connect a 300 resistance instead of coolant temperature
sensor to connector of coolant temperature sensor, ob- No Next
serve whether engine can start)
Check whether fuel pressure adjuster vacuum pipe has Yes Repair or replace
4
the symptom of loose or leakage. No Next step
Check fuel condition, observe whether appearance of Yes Replace fuel
5
malfunction symptom is after just adding fuel. No Next step

Connect adapter of electronic injection system, open Yes diagnosis

ignition switch, check whether the power supply of 64#,
6
49#, 50#, 63#pin is normal; check whether the grounding
of 43#, 48#, 5# pin is normal. No Repair related circuitry

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5.4 When cooling engine, hard start

Common malfunction position: 1. there is water in fuel; 2. fuel pump; 3. coolant temperature sen-
sor; 4. fuel injector; 5. ignition coil; 6. throttle body and idle bypass passage; 7. engine mechanical
part

Common diagnostic procedure:

Serial Continuous
Operation step Test result
NO. step
Connect fuel pressure meter (connecting position is front Yes Next step
1 end of inlet pipe of fuel distribution pipe assembly), start en- Repair supply fuel
gine, check whether fuel pressure is about 350kPa. No
system
Pull out high tension cable of a cylinder, connect spark plug, Yes Next step
make the distance from spark plug electrode to engine body
2 Repair ignition
is about 5mm, start engine and check whether there is the No
white-blue high tension fire. system
Pull out connector of coolant temperature sensor, start Repair circuitry or
Yes
engine, and observe whether engine can start. (serially replace sensor
3 connect a 2500 resistance instead of coolant temperature
sensor to connector of coolant temperature sensor, observe No Next step
whether engine can start)
Wash throttle and
Lightly step accelerating pedal, observe whether the start is Yes
4 idle passage
easy.
No Next step
Remove fuel injector, check whether the fuel injector has the Malfunction chan-
Yes
5 symptom of leakage or jam with fuel injector special wash- ged
ing analysis tester. No Next step

Check fuel condition, observe whether the appearance of Yes Replace fuel
6
malfunction symptom is after just adding fuel No Next step
Remove the en-
Check pressure condition of each cylinder, observe whether Yes gine mechanical
7 malfunction
there is the symptom of pressure shortage
No Next step
Connect adapter of electronic injection system, open ignition Yes Diagnosis
switch, check whether power supply of 12#, 13#, 44#, 45#,
8 Repair related
63# pin is normal; check whether grounding of 3#, 51#, 53#, No
61#, 80# pin is normal. circuitry

5.5 Rotation speed is normal, hard start anytime.

Common malfunction position: 1. there is water in fuel; 2. fuel pump; 3. coolant temperature sen-
sor; 4. fuel injector; 5. ignition coil; 6. throttle body and idle bypass passage; 7. intake passage; 8.
ignition timing; 9. spark plug; 10. engine mechanical part

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Common diagnostic procedure:

Serial Test re-

Operation step Continuous step
NO. sult
Check whether air filter is jammed, and whether intake Yes Repair intake system
1
passage has the symptom of leakage. No Next step
Connect fuel pressure meter (connecting position is front Yes Next step
2 end of inlet pipe of fuel distribution pipe assembly) start Repair fuel supply sys-
engine, check whether fuel pressure is about 350kPa. No
tem
Pull out high tension cable of a cylinder, connect spark Yes Next step
plug, make the distance from spark plug electrode to en-
3
gine body is about 5mm, start engine and check whether No Repair ignition system
there is the white-blue high tension fire.
Check spark plug of each cylinder, observe whether its Yes Next step
4
style NO. And clearance matches the criterion. No Adjust or replace
Repair circuitry or re-
Pull out connector of coolant temperature sensor, start en- Yes
5 place sensor
gine, and observe whether engine can start.
No Next step
Wash throttle and idle
Lightly step accelerating pedal, observe whether the start Yes
6 passage
is easy.
No Next step
Remove fuel injector, check whether the fuel injector has Yes Malfunction changed
7 the symptom of leakage or jam with fuel injector special
washing analysis tester. No Next step

Check fuel condition, observe whether the appearance of Yes Replace fuel
8
malfunction symptom is after just adding fuel. No Next step
Remove engine me-
Check pressure condition of each cylinder, observe wheth- Yes
9 chanical malfunction
er there is the symptom of pressure shortage
No Next step
Yes Next step
Check whether the ignition sequence and ignition timing
10
match criterion. No Repair ignition timing

Connect adapter of electronic injection system, open igni- Yes diagnosis

tion switch, check whether power supply of 64#, 49#, 50#,
11
63# pin is normal; check whether grounding of 43#, 48#,
5# pin is normal. No Repair related circuitry

5.6 Normally start, but unstable idle anytime

Common malfunction position: 1. there is water in fuel; 2. fuel injector; 3. spark plug; 4. throttle
and idle bypass passage; 5. intake passage; 6. idle adjuster; 7. ignition timing; 8. spark plug; 9.
engine mechanical part

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Common diagnostic procedure:

Serial Continuous
Operation step Test result
NO. step
Repair intake sys-
Check whether air filter has the symptom of jam, and in- Yes
1 tem
take passage has the symptom of leakage.
No Next step

Check whether the idle adjuster has the symptom of Yes Clean or replace
2
blocking. No Next step

Check spark plug of each cylinder, observe whether its Yes Next step
3
style NO. And the clearance obeys the criterion. No Adjust or replace

Check whether the throttle and idle bypass passage has Yes Wash
4
accumulated carbon. No Next step
Remove fuel injector, check if the fuel injector has the Malfunction
Yes
5 symptom of leakage, jam or flux over-bad with special changed
washing analysis tester. No Next step

Check fuel condition, observe whether the appearance of Yes Replace fuel
6
malfunction symptom is after just adding fuel. No Next step
Remove engine me-
Check pressure condition of each cylinder, observe if the Yes chanical malfunc-
7 tion
difference between cylinder pressure is great.
No Next step
Yes Next step
Check whether engine ignition sequence and ignition tim-
8 Repair ignition tim-
ing obey criterion. No
ing
Connect electronic injection adapter, open ignition switch, Yes Diagnosis
check whether power supply of 64#, 49#, 50#, 63# pin is
9 Repair related cir-
normal; check whether grounding of 43#, 48#, 5#pin is No
normal. cuitry

5.7 Normally start, unstable idle in process of warming up engine

Common malfunction position: 1, there is water in fuel; 2, coolant temperature sensor; 3, spark
plug; 4, throttle and idle bypass passage; 5, intake passage; 6, idle adjuster; 7, engine mechani-
cal part.

Common diagnostic procedure

Serial
Operation step Test result Continuous step
NO.
Check whether air filter has the symptom of jam, and Yes Repair intake system
1
intake passage has the symptom of leakage. No Next step

Check spark plug of each cylinder, observe whether Yes Next step
2
its style NO. And the clearance obeys the criterion. No Adjust or replace
Remove idle adjuster, check if accumulated carbon Wash related spare
Yes
3 exists in throttle body, idle adjuster and idle bypass parts
passage. No Next step

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Serial
Operation step Test result Continuous step
NO.
Pull out coolant temperature sensor connector, start Repair circuitry or re-
Yes
4 engine, observe whether when warming up engine, place sensor
the unstable idle exists. No Next step
Remove fuel injector, check if the fuel injector has the Yes Malfunction changed
5 symptom of leakage, jam or flux over-bad with special
washing analysis tester. No Next step

Check fuel condition, observe whether the appear- Yes Replace fuel
6
ance of malfunction symptom is after just adding fuel. No Next step
Remove engine me-
Check pressure condition of each cylinder, observe if Yes
7 chanical malfunction
the difference between cylinder pressure is great.
No Next step
Connect electronic injection adapter, open ignition Yes Diagnosis
switch, check whether power supply of 64#, 49#, 50#,
8
63# pin is normal; check whether grounding of 43#, No Repair related circuitry
48#, 5# pin is normal.

5.8 Normally start, unstable idle after warming up engine

Common malfunction position: 1, there is water in fuel; 2, coolant temperature sensor; 3, spark
plug; 4, throttle body and idle bypass passage; 5, intake passage; 6, idle adjuster; 7, engine me-
chanical part.

Common diagnostic procedure:

Serial
Operation step Test result Continuous step
NO.

Check whether air filter has the symptom of jam, and Yes Repair intake system
1
intake passage has the symptom of leakage.
No Next step
Check spark plug of each cylinder, observe whether Yes Next step
2
its style NO. and clearance obey the criterion. No Adjust or replace
Remove idle adjuster, check if accumulated carbon Wash related spare
Yes
3 exists in throttle body, idle adjuster and idle bypass parts
passage. No Next step
Pull out coolant temperature sensor connector, start Repair circuitry or re-
Yes
4 engine, observe whether when warming up engine, place sensor
the unstable idle exists. No Next step
Remove fuel injector, check if the fuel injector has the Yes Malfunction changed
5 symptom of leakage, jam or flux over-bad with special
No Next step
washing analysis tester.
Check fuel condition, observe whether the appear- Yes Replace fuel
6
ance of malfunction symptom is after just adding fuel. No Next step
Remove engine me-
Check pressure condition of each cylinder, observe if Yes
7 chanical malfunction
the difference between cylinder pressure is great.
No Next step

Connect electronic injection adapter, open ignition Yes Diagnosis

switch, check whether power supply of 64#, 49#, 50#,
8
63#pin is normal; check whether grounding of 43#,
48#, 5# pin is normal. No Repair related circuitry

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5.9 Normally start, unstable idle or misfire when there is part load. (for example: open A/C)

Common malfunction position: 1, A/C system; 2, idle adjuster; 3, fuel injector

Common diagnostic procedure:

Continuous
Serial NO. Operation step Test result
step
Remove idle adjuster, check if accumulated carbon ex- Wash related spare
Yes
1 ists in throttle body, idle adjuster and idle bypass pas- part
sage. No Next step
Observe when A/C is on, whether the output power of Yes To the fourth step
engine increases, that is, observe the change of igni-
2
tion advance angle, injecting fuel pulse width and intake No Next step
amount.
Connect electronic injection adapter, disconnect con- Yes Next step
nective wire of 75# pin of electronic control unit, check
3
when A/C is open, whether there is high level signal in No Repair A/C system
wire harness end.
Check whether A/C system pressure, electromagnetic Yes Next step
4
clutch of compressor is normal. No Repair A/C system
Remove fuel injector, check if the fuel injector has the Malfunction
Yes
5 symptom of leakage, jam or flux over-bad with special changed
washing analysis tester. No Next step
Connect electronic injection adapter, open ignition Yes Diagnosis
switch, check whether power supply of 64#, 49#, 50#,
6 Repair related cir-
63#pin is normal; check whether grounding of 43#, 48#, No
5#pin is normal. cuitry

5.10 Normally start, over high idle

Common malfunction part: 1, throttle body and idle bypass passage; 2, vacuum pipe; 3, idle ad-
juster; 4, coolant temperature sensor; 5, ignition timing.

Common diagnostic procedure:

Serial
Operation step Test result Continuous step
NO.
Check whether the accelerating pedal cable is too tight or Yes Adjust
1
blocked. No Next step

Check whether leakage exists in the intake system and re- Yes Repair intake system
2
lated vacuum pipeline. No Next step
Wash related spare
Remove idle adjuster, check if accumulated carbon exists in Yes
3 parts
throttle body, idle adjuster and idle bypass passage.
No Next step
Repair circuitry or
Pull out coolant temperature sensor connector, start engine. Yes
4 replace sensor
Observe whether the over-high idle exists.
No Next step
Yes Next step
5 Check whether the ignition timing of engine obey criterion.
No Repair ignition timing

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Serial
Operation step Test result Continuous step
NO.
Connect electronic injection adapter, open ignition switch, Yes Diagnosis
6 check whether power supply of 64#, 49#, 50#, 63#pin is nor- Repair related cir-
mal; check whether grounding of 43#, 48#, 5# pin is normal. No
cuitry

5.11 When accelerating the rotate speed can’t be increased or misfire

Common malfunction position: 1, fuel including water; 2, intake pressure sensor and throttle posi-
tion sensor; 3, spark plug; 4, throttle body and idle bypass passage; 5, intake passage; 6, idle ad-
juster; 7, fuel injector; 8, ignition timing; 9, exhaust pipe

Common diagnostic procedure:

Serial
Operation step Test result Continuous step
NO.
Yes Repair intake system
1 Check if the jam exists in air filter.
No Next step
Connect fuel pressure meter (connecting position is front Yes Next step
end of inlet pipe of fuel distribution pipe assembly), start
2 Repair supply fuel
engine, check whether the fuel pressure is about 350kPa No
when accelerating. system

Check spark plug of each cylinder, observe whether its style Yes Next step
3
NO. and clearance obey the criterion. No Adjust or replace
Wash related spare
Remove idle adjuster, check if accumulated carbon exists in Yes
4 part
throttle body, idle adjuster and idle bypass passage.
No Next step
Yes Next step
Check whether the intake pressure sensor, throttle position
5 Repair circuitry or
sensor and circuitry are normal. No
replace sensor
Remove fuel injector, check if the fuel injector has the symp- Yes Malfunction changed
6
tom of leakage, jam with special washing analysis tester. No Next step

Check fuel condition, observe whether the appearance of Yes Replace fuel
7
malfunction symptom is after just adding fuel No Next step

Check whether ignition sequence and ignition timing obey Yes Next step
8
criterion. No Repair ignition timing
Yes Next step
9 Check if the exhaust pipe is smooth. Repair or replace
No
exhaust pipe
Connect electronic injection adapter, open ignition switch,
check whether power supply of 64#, 49#, 50#, 63# pin is
10 Yes Diagnosis
normal; check whether grounding of 43#, 48#, 5# pin is nor-
mal.

5.12 When accelerating, slowly action

Common malfunction position: 1. fuel including water; 2. intake pressure sensor and throttle posi-
tion sensor; 3. spark plug; 4. throttle body and idle bypass passage; 5. intake passage; 6. idle ad-
juster; 7. fuel injector; 8. ignition timing; 9. exhaust pipe

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Common diagnostic procedure:

Serial NO. Operation step Test result Continuous step

Yes Repair intake system
1 Check if the jam exists in air filter.
No Next step
Connect fuel pressure meter (connecting position Yes Next step
is front end of inlet pipe of fuel distribution pipe as-
2 Repair supply fuel sys-
sembly), start engine, check whether the fuel pres- No
sure is about 350kPa when accelerating. tem

Check spark plug of each cylinder, observe whether Yes Next step
3
its style NO. and clearance obey the criterion. No Adjust or replace
Remove idle adjuster, check if accumulated carbon Wash related spare
Yes
4 exists in throttle body, idle adjuster and idle bypass parts
passage. No Next step
Yes Next step
Check whether the intake pressure sensor, throttle
5 Repair circuitry or re-
position sensor and circuitry are normal. No
place sensor
Remove fuel injector, check if the fuel injector has Yes Malfunction changed
6 the symptom of leakage, jam with special washing
analysis tester. No Next step
Check fuel condition, observe whether the appear- Yes Replace fuel
7 ance of malfunction symptom is after just adding
fuel. No Next step

Check whether ignition sequence and ignition tim- Yes Next step
8
ing obey criterion. No Repair ignition timing
Yes Next step
9 Check if the exhaust pipe is smooth.. Repair or replace
No
exhaust pipe
Connect electronic injection adapter, open ignition Yes Diagnosis
switch, check whether power supply of 64#, 49#,
10
50#, 63#pin is normal; check whether grounding of No Repair related circuitry
43#, 48#, 5# pin is normal

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5.13 When accelerating, no power or poor performance

Common malfunction position: 1. fuel including water; 2. intake pressure sensor and throttle posi-
tion sensor; 3. spark plug; 4. ignition coil; 5. throttle body and idle bypass passage; 6. intake pas-
sage; 7. idle adjuster; 8. fuel injector; 9. ignition timing; 10. exhaust pipe.

Common diagnostic procedure:

Serial NO Operation step Test result Continuous step

Check if the malfunction such as clutch skidding, Yes repair
1 low tire pressure, braking sluggish, wrong tire size
and false four wheel positioning exist. No Next step

Yes Repair intake system

2 Check if the jam exists in air filter.
No Next step
Connect fuel pressure meter (connecting position Yes Next step
is front end of inlet pipe of fuel distribution pipe as-
3 Repair supply fuel sy-
sembly), start engine, check whether the fuel pres- No
sure is about 350kPa when accelerating. stem
Pull out high tension cable of a cylinder, connect Yes Next step
spark plug, make the distance from spark plug elec-
4 trode to engine body is about 5mm, start engine
and check whether intensity of high tension fire is No Repair ignition system
normal.

Check spark plug of each cylinder, observe whether Yes Next step
5
its style NO. and clearance obey the criterion. No Adjust or replace
Remove idle adjuster, check if accumulated carbon Yes Washing related parts
6 exists in throttle body, idle adjuster and idle bypass
passage. No Next step

Yes Next step

Check whether the intake pressure sensor, throttle
7 Repair circuitry or re-
position sensor and circuitry are normal. No
place sensor
Remove fuel injector, check if the fuel injector has Yes Malfunction changed
8 the symptom of leakage, jam with special washing
analysis tester. No Next step
Check fuel condition, observe whether the appear- Yes Replace fuel
9 ance of malfunction symptom is after just adding
fuel. No Next step

Check whether ignition sequence and ignition tim- Yes Next step
10
ing obey criterion. No Repair ignition timing
Yes Next step
11 Check if the exhaust pipe is smooth. Repair or replace ex-
No
haust pipe
Connect electronic injection adapter, open ignition Yes Diagnosis
switch, check whether power supply of 64#, 49#,
12
50#, 63# pin is normal; check whether grounding of No Repair related circuitry
43#, 48#, 5# pin is normal

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6. M7 system Diagnosis Instrument Using Direction

The chapter takes S.W.G 99-02 engine malfunction diagnosis for example, and specifies how to
diagnose and analyze the malfunction of M7system with the engine. Because the diagnosis in-
strument is developed by the manufacture, there may be some differences in purchase and func-
tion. Please note when reading this chapter.

The value and related content in this chapter is for reference only.
6.1 Diagnosis appearance is shown as follow

• fault diagnosis tester

Electronic fuel injection engine fault diagnosis tester

fault diagnosis tester

Engine fault diagnosis tester
1. Self-diagnosis
2. Engine condition display
3. Ignition advance angle

6.2. The introduction of diagnosis operational panel

(1) On the left of the panel is a liquid crystal display, displaying various Chinese information.

(2) On the right of the panel is a 4×4 keyboard, definition as follows:

“0-9”: Number input key

Confirming key: used to confirm the order or data input

Exit Key: Used to return to previous menu from sub-menu.

“ ▽ ”, “ △ ”: Used for menu selection

Help key: used for simple operational information

6.3. Diagnosis instrument function introduction

(1) Self-diagnosis

Mainly Including: Read DTC, clear DTC

(2) System parameter display

Mainly Including: The display of main parameter, parameter, and sensor signal voltage;

(3) System condition

Mainly Including: The display of program condition, cooling system, steady working condition, dy-
namic driving mode, exhaust control, oxygen sensor, idling, fault light, emergency operation, air
conditioner.

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(4) Actuation test

Mainly including: The function test of fault light, fuel pump, air conditioner relay, fan control, igni-
tion test, and single cylinder fault block oil.

(5) Odometer

Mainly including:The display of vehicle drive mileage,drive time

(6) Version information

Mainly including: The display of Vehicle frame number (optional), ECU hardware, ECU software.
6.4 The diagnosis instrument use introduction

Online operation

Welcome to use the system

1. BOSCH
ConnectM797
the online line 1. Connect the online wire
BOSCH M154 2. Turn on the ignition switch
BOSCH M382
3. Select the right system, press the “con-
firm” key.

If the system selects wrong or doesn’t turn

the switch on at this time, return to “system
In connecting select”.

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Self-diagnosis function

Please select function RB

+ Self-diagnosis
+ System parameter display
+System condition After selecting the function with 4 key(upward
select key)and 8 key(downward select
key),press “confirm”key;Press “exit” key to go
+Actuation test
back to main function layout.
+Odometer
+ Version information

Self-diagnosis function –read DTC

Self-diagnosis RB

- Read DTC
It can read DTC in the ECU malfunction
- Clear DTC memory with “read DTC”function,including
steady state and the incident malfunction..

Read DTC 2-1 RB

The left figure as shown:

1. 2-1 means there are two DTC.It;s the

P0630
first one.
VIN code not program Current
2. “Current” shows that it’s a stable fault.
“Incident” shows that it’s an incident
fault.

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Self-diagnosis-clear DTC

Self-diagnosis RB

- Read DTC

- Clear DTC Clear DTC in ECU fault memory with the

“Clear fault” function after the fault is repaired.

Clear DTC RB

Displaying “OK” means “Clear fault” opera-

tion finishes. Press “Confirm” key to return to
OK! “Self-diagnosis” layout.

System parameter display function

Please select function RB

+ Self-diagnosis

+ System parameter display

Press “Confirm” key after selecting the re-
+ System state quired function with key 4 (upward select key)
and key 8(downward select key)

+ Actuator tester
+ Odometer
+ Version information

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System parameter display function-Main parameter

System parameter display RB

+ Main parameter Press “Confirm” key or press “exit” key to re-

+ Parameter turn to main function layout after selecting the
+ Voltage required function with key 4 (upward select
key)and key 8(downward select key)

Rotating speed 754 rpm

Coolant temperature 85 c Choose different layouts with key 4 (upward

Throttle opening 0d select key) and key 8(downward select key)
Ignition advance angle 9.5 d

CAUTION
Injection pulse width 3.5 ms Caution: Turn on the ignition switch. Do
Intake pressure 34.0 kpa not start the engine. At this time, “intake
pressure “display about101.0kPa, that is
Intake temperature 54 c
air pressure
Speed 0 km/h

System voltage 13.9 V

Injection revises 1.00
Canister scour rate 8 %
Idle air control 19 %

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Oxygen sensor 400 mV

Displaying “400mV”, shows the current front

oxygen sensor signal voltage

System parameter display function-Parameter

System parameter display RB

Press “Confirm” key or press “exit” key to re-

+ Main parameter turn to main function layout after selecting the
required function with key 4 (upward select
+ Parameter key)and key 8(downward select key)

+ Voltage

Target idle 750 rpm

Choose different layouts with key 4 (upward

Load 20 % select key) and key 8(downward select key)
Environment temperature 21 c “Closed time” means ignition coil magnetizing
Closed time 3.8 ms time

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Evaporator temperature 26 c
Intake flow 7.4 kg/h
Oil consumption 0.5 L/h

System parameter display function –Voltage

System parameter display RB

+ Main parameter Press “Confirm” key or press “exit” key to re-

turn to main function layout after selecting the
+ Parameter
required function with key 4 (upward select
+ Voltage key)and key 8(downward select key)

Throttle signal 0.26 V

Coolant temperature 1.13 V
Intake temperature 1.97 V Choose different layouts with key 4 (upward
Intake pressure 1.3 V select key)and key 8(downward select key)

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Knock signal 01 0.25 V

Knock signal 02 0.25 V

System state display function

Please select function RB

Please select function RB
+ Self-diagnosis
+ System parameter display
+ System state
Press “Conform” key after selecting required
function with key 4 (upward select key) and
key 8(downward select key)
+ Actuation
+ Odometer
+ Version information

System state RB
+ Program stage
+ Cooling system
+ Stable work condition
+ Dynamic work condition Press “Confirm” key or press “exit” key to re-
turn to main function layout after selecting the
+ Exhaust control
required function with key 4 (upward select
+ Oxygen sensor key)and key 8(downward select key)
+ Idle
+ Indicator
+ Emergency operation
+ Air conditioner

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System state display function-Program state

Program state 00000000

Safe system N
VIN Programmed N Displaying “N” Indicates state No

Displaying “Y” indicates state Yes

System state display function-Cooling system

Cooling system 00000000

Fan1 N Displaying “N” Indicates state No

Displaying “Y” indicates state Yes

Fan2 N

Fan3 N

System state display function-Stable work condition

Stable work condition 00000011

The item includes two layouts. Selecting re-
quired layout with key 4 (upward select key)
Ignition switch Y and key 8(downward select key)

Displaying “N” Indicates state No.

Main relay Y
The related execution component doesn’t
Fuel pump Y work

Displaying “Y” Indicates state Yes. The re-

Start motor N lated execution component works.

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Idle run N
Phase signal N
Coolant temperature N Displaying “N” Indicates state No.
Speed signal N Related condition is not met

Displaying “Y” Indicates state Yes.

Related conditions meet

System state display function-Dynamic work condition\

Dynamic work condition 00000001

Throttle valve idle position Y

The item includes two layouts. Selecting re-
Throttle valve all open N quired layout with key 4 (upward select key)
and key 8(downward select key)
Decelerate, fuel cut-off N Displaying “N” Indicates state No.

Accelerate, add oil N The related execution component doesn’t

work

Displaying “Y” Indicates state Yes. The re-

lated execution component works.

System state display function-Exhaust control

Exhaust control 00000101

Air fuel adjust Y Displaying “N” Indicates state No.

Related condition is not met

Exhaust gas recycle N
Displaying “Y” Indicates state Yes.
Canistere rode valve N
Related conditions meet
Catalyst protection adding N

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System state display function –Oxygen sensor

Oxygen sensor 00000000

Oxygen signal concentration N Displaying “N” Indicates state No.

Oxygen sensor is heating N Related condition is not met

Displaying “Y” Indicates state Yes.

Related conditions meet

System state display function -Idle

Idle 00000001

Throttle valve idle position Y Displaying “N” Indicates state No.

Electrical apparatus load1 N Related condition is not met
Electrical apparatus load2 N
Displaying “Y” Indicates state Yes.

Related conditions meet

System state display function –Emergency operation

Emergency 00000000
The layout is applied to the system with the
electronic throttle valve.
Throttle valve position N
Electronic accelerator power-down N Displaying “N” Indicates state No.

Related condition is not met

Displaying “Y” Indicates state Yes.

Related conditions meet

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System state display function –Air conditioner

Air conditioner 00000000

Air conditioner N Displaying “N” Indicates state No.

Air conditioner request N Related condition is not met
Air conditioner compressor N
Displaying “Y” Indicates state Yes.

Related conditions meet

Actuation test function

Please select function RB

+ Self-diagnosis
+ System display parameter
+ System condition
Press “Confirm” key after selecting required
function with key 4 (upward select key) and
key 8(downward select key)

+ Actuat or test
+ Odometer
+ Version information

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Actuator test RB

- Maintain light
- Fuel pump
- Air conditioner relay Press “Confirm” key or press “exit” key to re-
turn to main function layout after selecting the
required function with key 4 (upward select
key)and key 8(downward select key)

- Fan

- Ignition

- Injection

Actuator test function-Maintain light

Malfunction light RB

- Turn on
Please observe Turn on ignition switch, but don’t start engine.
- Turn off
Press “Confirm” key and observe if the asso-
ciated state changes of fault light is normal or
not after selecting the required function with
key 4 (upward select key) and key 8(down-
ward select key)
- Fan

- Ignition

- Injection

Actuator test function –Fuel pump

Fuel pump RB

- Turn on Turn on ignition switch, but don’t start engine.

Please observe
- Turn off
Press “Confirm” key and observe if the asso-
ciated state changes of oil pump relay and oil
pump is normal or not after selecting the re-
quired function with key 4 (upward select key)
and key 8(downward select key).

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Actuator test function –Air conditioner relay

Air conditioner relay RB

- Turn on Turn on ignition switch, but don’t start engine.

Please observe
- Turn off Press “Confirm” key and observe if the asso-
ciated state changes of air conditioner relay
and oil pump is normal or not after selecting
the required function with key 4 (upward se-
lect key) and key 8(downward select key).
Actuator test function-Fan

Actuator test function -Fan

Fan RB

- Turn on Turn on ignition switch, but don’t start engine.

Please observe
- Turn off
Press “Confirm” key and observe if the as-
sociated state changes of fan is normal or not
after selecting the required function with key
4 (upward select key) and key 8(downward
select key).

Actuator test function –Ignition

Ignition RB Turn on ignition switch, but don’t start engine.

Remove associated cylinder ignition wire set
Cylinder 01 Please observe and connect to spark plug alongside the cyl-
inder.

Press “Confirm” key and observe if the spark

intensity of the associated spark plug is nor-
mal or not after selecting the required cylin-
der with key 4 (upward select key) and key
8(downward select key).

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Actuator test function –Fuel injection

Fuel injection RB

Cylinder 01 Turn on ignition switch, but don’t start engine.

Please observe
Fuel cut-off
Press “Confirm” key and observe if the jitter
degree is consistent when the fuel in each
cylinder of the engine is cut-off after selecting
the associated cylinder with key 4 (upward
select key) and key 8(downward select key).

Please select function RB

+ Self-diagnosis
+ System parameter display
+ System state Press “Confirm” key after selecting the re-
quired function with key 4 (upward select key)
and key 8(downward select key)
+ Actuator display
+Odometer
+ Version information

Odometer RB

Drive mileage
0 0 0 0 5 5 8 1 km It’s used to know the vehicle information in
the after-sales. Press “exit” key to return to
Drive time
main function layout.
0 0 0 6 5 7 9 3 min

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Version information display function

Please select function RB

+ Self-diagnosis
+ System parameter display
+ System state Press “Confirm” key after selecting the re-
quired function with key 4 (upward select key)
and key 8(downward select key)
+ Actuator display
+Odometer
+ Version information

Version information RB

VIN ：**************
It’s used to know the information of engine
******************* ECU hardware number, software number and
VIN (optional) .Press “exit” to return to main
Hardware ：********* function layout.

Software ：**********

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7. Accessory
7.1 Table on installation force/torque standard of spare parts

NO. Part name Installation torque (NM)

1 Intake pressure and temperature sensor 3.3
2 Coolant temperature sensor 20 (Max)
3 Knock sensor 20 ± 5
4 Oxygen sensor 50 ± 10
5 Throttle position sensor 2 ± 0.5
6 Wheel speed sensor 8±2
7 Phase sensor 8 ± 0.5
8 Electromagnetism injector 6
(the first phase)2 ± 1
9 Idle actuator
(the second phase)7 ± 1

7.2 Maintenance regulation of electronic fuel injection system

7.2.1 Family vehicle

Specification:

1. The criterion is suitable for family vehicle;

2. The interval of maintenance is decided by mileage or interval, which first get to target;

3. The criterion is based on the premise that the vehicle is used normally as the design, so we
must strictly conform it.

Mileage
10 20 30 40 50 60 70 80
Items x1000km
Month 3 6 9 12 15 18 21 24
Ignition Coil I I I I
Ignition Cam I I I I
Ignition Cap I I I I
Ignition Wire I I I I
Spark Plug I I I R
Ignition Timing I I I I
Engine Idling
I I I I
Speed
Fuel Tank I C
Fuel Filter R R R R
Fuel Injector C* C* C* C*
Air Filter I R I R
EWD or Stepper
C C C C
Air Bypass
Throttle Body C C C C
Emission Check I I I I

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Mileage
10 20 30 40 50 60 70 80
Items x1000km
Month 3 6 9 12 15 18 21 24
Check by Diag-
I I I I
nostic Tool

7.2.2 Taxi

Specification:

1. The criterion is intended for taxi;

2. The interval of maintenance is decided by mileage or time interval, whichever is reached

first;

3. The criterion is based on the premise that the vehicle is used normally as the design, so we
must strictly abide to it.

Mileage
20 40 60 80 100 120 140 160
Items x1000km
Month 3 6 9 12 15 18 21 24
Ignition Coil I I I I I I I I
Ignition Cam I I I I I I I I
Ignition Cap I I I I I I I I
Ignition Wire I I I I I I I I
Spark Plug I R I R
Ignition Timing I I I I
Engine Idling
I I I I
Speed
Fuel Tank C C
Fuel Filter R R R R R R R R
Fuel Injector C* C* C* C* C* C* C* C*
Air Filter I R I R I R I R
EWD or Stepper
I C I C I C I C
Air Bypass
Throttle Body I C I C I C I C
Emission Check I I I I
Check by Diag-
I I I I
nostic Tool

Note: R-Replace

C-Clean

I - Inspect (Replace the spare parts when find out failure in inspection.)

C*- The maintenance of fuel injector had better clean by a special tool --- fuel injector
cleaner.

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7.3 DTC (PCODE) Sheet

DTC
Identification Description Fault
Max Min Signal Abnormal
Crankshaft position sensor
bm P0335 P0335 P0335 P033m6 33
signal fault
Throttle valve position sensor
dk P0123 P0122 P0120 P0120 31
circuit fault
ev1 Injector 1control circuit fault P0201 P0201 P0201 P0201 31
ev2 Injector 2control circuit fault P0203 P0203 P0203 P0203 31
ev3 Injector 3control circuit fault P0204 P0204 P0204 P0204 31
ev4 Injector 4control circuit fault P0202 P0202 P0202 P0202 31
λ closed-loop control self-
frao study threshold Multiplication P0171 P0172 P0170 P0170 5
part overrun
λ closed-loop control self-
frau study threshold Multiplication P0171 P0172 P0170 P0170 5
part overrun
hsv Oxygen sensor heating fault P0135 P0135 P0135 P0135 31
Air compressor relay control
Kose P0647 P0646 P0645 P0645 31
circuit fault
Kpe Fuel pump control circuit fault P0230 P0230 P0230 P0230 31
krnt Knock zero test diagnosis P0324 P0324 P0324 P0324 5
krof Knock offset diagnosis P0324 P0324 P0324 P0324 5
krtp Knock test pulse diagnosis P0324 P0324 P0324 P0324 5
ks1 Knock sensor circuit fault P0325 P0325 P0325 P0325 31
Idle speed control deviated a
llr P0507 P0506 P0505 P0505 31
set speed fault
Lm Intake pressure sensor fault P0108 P0107 P0105 P0106 31
Lsv Oxygen sensor fault P0132 P0131 P0134 P0130 31
Luea Fan A control circuit fault P0480 P0480 P0480 P0480 31
N Rotating sensor fault P0335 P0335 P0335 P0336 33
Ph Phase sensor fault P0343 P0342 P0340 P0340 31
λ closed-loop control self-
rkaz study threshold addition part P0171 P0172 P0170 P0170 5
overrun
stpe Stepper control circuit fault P0509 P0508 P0511 P0511 31
Svse SVS light control circuit fault P1651 P1651 P1651 P01651 5
Intake temperature sensor
Ta P0113 P0112 P0110 P0111 31
fault
Canister control valve control
teve P0445 P0444 P0443 P0443 31
circuit fault
Water temperature sensor
Tm P0118 P0117 P0115 P0116 31
fault
Air conditioner evaporator
Tevrd P1530 P1530 P1530 P1530 5
temperature sensor fault
ub Power supply fault P0563 P0562 P0560 P0560 31
vfz Vehicle speed sensor fault P0500 P0500 P0500 P0500 31

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7.4 Project sheet

The accessory sheet provided by UAES.

7.5 Wire harness figure

Please strictly refer to it in the maintenance.

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Section 5 488QB ME7 Management System

Foreword
With the development of national economy in China, car ownership is increasing gradually and
environment protection regulations become much stricter. Since July 1, 2007, State III Emission
Regulation has been implemented for new cars. Recently, the National Environment Protection
Bureau has given a notice that a license plate is forbidden to be given to the car with carburetor
engine and light vehicle since September 1, 2001. Since July, 2007, State III Emission Regulation
has also been implemented for the trucks below 3.5 tons. In fact, many automobile companies
develop products based on State IV instead of State III. Beijing 2008 Olympic Game pushes for-
wards vehicle emission control cause.
Closed-loop control gasoline quantitation technology and three-way catalytic converter will reduce
toxic substance in vehicle emissions by more than 92%. It is an irreversible development tenden-
cy that electronic control gasoline injection technology replaces the carburetor. This shows that
carburetor engine era is over and electronic control gasoline injection engine era starts.
United Automotive Electronic Systems Co. Ltd is the biggest and the most influential supplier of
vehicle engine electronic control gasoline injection system. Since 1996, it has supplied MOTRON-
IC series electronic fuel injection system and parts imported from Germany BOSCH company to
each automobile company in China. So-called MOTRONIC is a trade name, which does not con-
tain specific meaning. However, MOTRONIC system has a certain technical feature, i.e., engine
fuel quantitation electronic control and ignition timing electronic system is combined. Two systems
that are originally separate share one set of sensor, electronic control unit and power supply. It is
self-evident that MOTRONIC system has ignition timing electronic control function. This improves
engine performance greatly.
Like other electronic control gasoline fuel systems, MOTRONIC system can reduce vehicle emis-
sion greatly, but it brings difficult to the engine maintainer who is only familiar with the traditional
carburetor engine. Vehicle maintainer thinks carburetor engine is visible and tangible. But, there
are no mechanical components in electronic control gasoline injection engine, which are replaced
by various electronic components. Originally, the maintainer even the driver can adjust the carbu-
retor or distributor by himself; but now, the data is stored in computer chip. Ordinary maintainer
cannot modify data through electronic instrument to make troubleshooting. If one electronic com-
ponent in the system is faulty, it cannot be seen from the appearance. Normally, an instrument is
required to test and recognize it. Therefore,the maintainer does not know how to maintain elec-
tronic control gasoline injection engine. According to this condition, we compile this maintenance
manual. We hope it can play a role in the following two aspects: one on hand, it helps engineers
from engine works or vehicle manufacturer understand engine electronic control system deeply;
on the other hand, it helps maintainers in various regions to repair electronic control gasoline in-
jection engine.
This manual first introduces composition and working principle of electronic control gasoline injec-
tion system. Next, it introduces structure and performance of all parts in the system.
Generally, during the course of maintaining electronic control gasoline injection system, fault di-
agnosis tester is an essential tool. Fault diagnosis tester can call fault information record stored
in ECU. In order to help the reader to understand true meaning of each fault deeply, this manual
lists fault information recording conditions set by ECU. But many faults are not directly determined
only according to fault information record. However, it is necessary to go through a series of anal-
ysis to find out the faults. Therefore, this manual mainly describes how to find the fault according
to fault information record.
Because electronic control component exists, this is new content for engine fault reason. In other

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words, the same engine fault may arise from mechanical reason or electronic component. In ad-
dition, the engine fault cannot be diagnosed only by fault diagnosis tester. Therefore, this manual
describes how to find a fault based on engine symptom and electronic control system.

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1. Electronic fuel injection system notice

1.1 General maintenance notice

• Only digital multimeter can be used to conduct inspection for the Electronic Fuel Injection
System.

• Please use original parts for repair. Otherwise the Electronic Fuel Injection System will not
work normally.

• During the course of maintenance, only lead-free gasoline can be used.

• Please comply with standard diagnosis process for repair jobs.

• Do not decompose or dismantle the components of the Electronic Fuel Injection System in
the process of repair.

• During the course of maintenance, when holding electronic components (electronic control
unit, sensor), be careful and do not let them fall down to the ground.

• Establish the awareness of environmental protection, and dispose effectively waste gener-
ated in the process of repair.
1.2 Notes for maintenance

1) Do not remove any parts in the Electronic Fuel Injection System or other connectors from the
installation position without careful thinking. Otherwise, accidental damage, or water, oil stain
might enter the connectors to impact the Electronic Fuel Injection System.

2) When disconnecting and connecting connectors, it shall be at OFF. Otherwise, electrical

components may be damaged.

3) When simulating heat state of the fault and making maintenance work that leads to tempera-
ture rise, electronic control unit temperature never exceeds 80°C.

4) All fuel lines use high pressure resistant fuel pipes as the fuel supply pressure in the Elec-
tronic Fuel Injection System is rather high (about 350kPa). Even when the engine does not
run, fuel pressure in the fuel line is rather high. During the course of maintenance, do not
remove fuel pipe at random. Before removing fuel pipe, fuel system shall be discharged.
Discharging method as follows: Start the engine to run idly, connect the diagnosis tester and
go into “actuator test”, turn off fuel pump until the engine goes out. Remove the oil pipes and
replace the fuel filter by qualified technicians in a well-ventilated place.

5) Do not electrify the oil pump when removing the electric fuel pump from the fuel tank. Other-
wise electric spark might be generated to cause fire.

6) It is not allowed to conduct running test of fuel pump in the dry state or under water. Other-
wise the life will be shortened. In addition, do not conduct a wrong connection of anode and
cathode of the fuel pump.

7) Just conduct jump spark test when necessary if the ignition system is being checked. Try to
keep the test duration as short as possible. Do not open the throttle during the inspection
and examination. Otherwise lots of unburned gas might enter the exhaust pipe, leading to
damage of catalytic converters.

8) As adjustment of idling speed is controlled completely by the Electronic Fuel Injection Sys-
tem, there is no need of manual adjustment. The throttle limit screw of the throttle body has
been adjusted well in the factory of the manufacturer. Any user is not allowed to arbitrarily

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change its initial position.

9) When connecting the battery, do not reverse the positive and negative electrodes of the bat-
tery to avoid damaging electronic components. This system adopts negative earth.

10) Do not remove the battery cables when the engine is running.

11) Anode cable, cathode cable of the battery and the electronic control units must be removed
before welding on the vehicle.

12) Do not check input/output electrical signal of the parts through a method of piercing the cable
warpage.
1.3 Maintenance tool list

Tool name:

Electronic fuel injection system diagnosis

tester

Functions:

Read/erase electronic fuel injection system

trouble codes, observe data stream and mo-
tion test of components.

Tool name:

Electronic fuel injection system adapter

Functions:

Measure electrical signal of each pin in the

electronic control unit, and check circuits.

Tool name:

Ignition timing light

Functions:

Check the engine ignition timing.

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Tool name:

Digital multimeter

Functions:

Check characteristic parameters of electronic

fuel injection system such as voltage, current
and resistance.

Tool name:

Vacuum gauge

Functions:

Check pressure in the intake manifold.

Tool name:

Cylinder pressure gauge

Functions:

Check pressure in each cylinder.

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Tool name:

Fuel pressure gauge

Functions:

Check the fuel system pressure, and deter-

mine working condition of the fuel pump and
the fuel pressure regulator in the fuel system.

Tool name:

Exhaust gas analyzer

Functions:

Check vehicle emission to help diagnosis of

fault of electronic fuel injection system.

Tool name:

Injector cleaning analyzer

Functions:

Analyse cleaning of the injector.

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1.4 Abbreviation comment in maintenance manual

DG Speed sensor
DVE Electronic throttle body
FPM Electronic accelerator pedal
DR Fuel pressure regulator
DS-S-TF Intake pressure temperature sensor
ECU Electronic control unit (commonly known as: computer)
EKP Fuel pump
EMS Engine management system
EV Fuel injector
LSF Heated oxygen sensor
KS Knock sensor
KSZ Fuel distribution pipe assembly
KVS Fuel distribution pipe
PG Phase sensor
ROV Ignition system with distributor block
RUV Ignition system without distributor block
TEE Oil pump bracket assembly
TEV Canister control valve
TF-W Coolant Temp Sensor
ZSK Ignition coil

2. ME7 system introduction

2.1 Basic Principle of the System

2.1.1 System Overview: ME7-Motronic engine management system

The engine management system generally consists of three components - sensor, microproces-
sor (ECU) and actuator. The system may control intake air amount, fuel injection amount and igni-
tion advance angle. For basic structure, see Fig. 3-1.

Diagnosis Diagnosis
Sen ECU Actuator

Engine

Fig. 3-1 Engine electronic control system composition

In the engine electrical control system, sensors as input components are used to measure various
physical signals (such as temperature and pressure) and then convert them into corresponding
electrical signal; functions of ECU is receive input signal of sensors, and then process signals ac-

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cording to specified programs and generate corresponding control signal outputting to the power
drive circuit which can drive various actuators to carry out different actions so that the engine may
run according to control strategies preset; at the same time, the fault diagnosis system of ECU
monitors the various components or control functions in the system. Once fault is detected and
confirmed, the system will save trouble code and then activate function “limp home”. When that
the fault is eliminated is detected, the normal value is restored.

ME7 engine electronic control management system is characterized by the use of a torque-based
control strategy. Main purpose of the torque-based control strategy is link lots of different control
targets. This is only way to integrate various functions in the different ECU variants according to
engine and vehicle models. For ME7 engine electronic control system structure, see Fig. 3-2.

Phase sensor
Ignition coil
Fuel distribution pipe
Canister control valve assembly

Phase sensor
Intake air temperature
sensor

Oxygen sensor

Front catalytic converter

Knock
Air Throttle valve Sensor Temperature
Sensor
(ETC) Oxygen
sensor
Electronic control
unit (ECU)
Speed sensor
Main catalyst

Accelerat

CAN

MIL

Diagnosis
interface
Electric fuel pump
Anti-theft

Source: GS/VSA 6402e

UAES parts
ETC = Electronic throttle
EOBD = Diagnosis inside the vehicle (Europe)
RLFS = No oil return/oil supply system

Fig. 3-2 ME7 engine electronic control system structure diagram

Basic components of ME7 engine electronic control system structure:

Electronic control unit (ECU) Electronic accelerator pedal

Air mass flowmeter (It depends on
Fuel injector
the project)
Intake pressure /temperature sensor
Electronic fuel pump
(It depends on the project)
Coolant Temp Sensor Fuel pressure regulator
Electronic throttle body Oil pump bracket
Phase sensor Fuel distribution pipe
Speed sensor Canister control valve
Knock sensor Ignition coil
Oxygen sensor

ME7-Motronic engine management system is an electronically-controlled gasoline engine control

system, providing many control characteristics about operator and vehicle equipment. The system
provides various control signals for engine running using a combined manner of open loop and
close loop (feedback) control. Main function of the system:

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1) Apply basic management functions of engine in physical modes

• Torque-based system structure

• Cylinder capacity is determined by the intake pressure sensor/air flow sensor

• Fuel/air mixture control function is improved in static and dynamic condition.

• λClosed-loop control

• Sequential fuel injection

• Ignition timing, including cylinder knock control

• Emission control function

• Catalytic converter heating

• Canister control

• Idle speed Control

• Limp home

• The speed is sensed by incremental system.

2) Additional function

• Anti-theft device function

• Connection between torque and external system (such as drive mechanism or vehicle dy-
namic control)

• Control for several parts of the engine

• Provide an interface matching with EOL-programming tool and maintenance tool

3) On-line diagnosis OBD II

• Complete a series of OBD II function

• Management system used for diagnosis function

2.1.2 Torque structure: ME7 system based on torque control

In torque-dependentME7 engine management system, all internal and external requirements of

the engine are defined by engine torque or efficiency requirements, as shown in figure 22.3. Con-
vert various engine requirements into torque or efficiency control variables, and then the center
torque demand coordinator module processes the variables for the first time. The ME7 system
can arrange the conflicting requirements in order of priority, and then conduct the most important
requirement and may obtain required engine control parameters such as fuel injection time and
ignition timing by the torque converting module. Execution of this control variable does not have
impact on other variables. This is a benefit of the torque-dependent control system.

Likewise, during the engine matching, the torque-dependent control system is variable-inde-
pendent. Only engine data are used in matching the engine characteristics and pulse spectrum
and other power functions and variables did not interfere. Therefore, repeated calibration can be
avoided, simplifying the matching process and reducing the matching cost.

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Efficiency
requirements
 Engine startup
 Catalytic heating
 Idle control

Efficiency

Exterior torque requirements Injection time

 Cruise control Torque requirements Torque
 Speed limit controller transition
 Dynamic control of complete Torque coordination and To realize the
vehicle efficiency requirements Torque expected torque Slave cylinder fuel
 Driveability cut-off

Interior torque requirements

Torque
 Engine startup Ignition timing
 Idle control
 Speed control of engine
 Engine protection

Fig. 3-3 ME7 Torque-based system structure

Compared to the former M-series engine EFI management system, ME7 system has following
main features:

• New engine function structure using torque as variable; it is the most compatible with other
systems and so it is very expandable;

• New modular software and hardware structure makes excellent portability;

• Basic characteristics of the engine is based on modules and mutually independent, simplify-
ing the calibration process;

• With phase sensor, sequential fuel injection is helpful to improve emission;

• The system is integrated with anti-theft function;

• Improve driving performance through centralized coordination of the various torque require-
ments;

• 16-bit central processing unit, 24 MHz clock frequency, 512k buffer memory;

• The system can be expanded according to future needs, such as, future emissions regula-
tions, OBDII and electronic throttle feature.
2.2 control signal: ME7 system input/output signal

Main sensor input signals of ECU in the M7 system include:

• Intake air pressure signal

• Accelerator pedal signal

• Intake air temperature signal

• Throttle angle signal

• Coolant temperature signal

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• Engine speed signal

• Phase signal

• Knock sensor signal

• Oxygen sensor signal

• Vehicle speed signal

• A/C pressure signal

After processing the information entering the ECU, generate required actuator control signals.
These signals are amplified in the output drive circuit and then transferred to various correspond-
ing actuator. These signals include:

• Electronic throttle openness

• Injection timing and fuel injection duration

• Oil pump relay

• Canister control valve opening degree

• Ignition coil dwell angle and ignition advance angle

• A/C compressor relay

• Cooling fan relay

2.3 System function introduction

2.3.1 Start control

During starting, it is necessary to adopt a special calculation method to control charging amount,
fuel injection and ignition timing. In the beginning stage of this process, air in the intake manifold
is stationary, and the intake manifold internal pressure is displayed as surrounding atmosphere
pressure. Throttle is closed. Idle speed regulator specifies a fixed parameter based on start tem-
perature.

In a similar process, specific “Injection timing” is designated as the initial injection pulse.

Fuel injection amount varies with temperature of the engine in order to facilitate forming of oil film
in the intake manifold and the cylinder wall. Therefore, when the engine reaches a certain engine
speed, the fuel/gas mixture should be enriched.

Once the engine starts running, the system immediately begin to reduce the start enriching until
starting condition (600…700min-1) is finished.

Ignition angle is also constantly adjusted in the starting conditions. Vary with engine temperature,
intake air temperature and engine speed.
2.3.2 Warming up and three-way catalytic converter heating control

After the engine starts at low temperature, cylinder charging capacity, fuel injection and electronic
ignition are adjusted to compensate higher torque of the engine; this process proceeds until the
proper temperature threshold value is obtained.

In this stage, the most important is the quick heating of the catalytic converter because quick
transfer to the catalytic converter may start working and greatly reduce emission. In this working

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condition, moderately delayed ignition timing may use exhaust gas for “heating of catalytic con-
verter”.
2.3.3 Acceleration/deceleration and reversed towing fuel cut-off control

Some fuel injected to the intake manifold can not enter the cylinder in time to join the subsequent
combustion process. On the contrary, the fuel may form a layer of oil film in the wall of the intake
manifold. If the load increases and the fuel injection duration is prolonged, fuel amount stored in
the oil film may increase dramatically.

When the throttle opening increases, the fuel partially ejected is absorbed by the film. Therefore,
the corresponding additional amount of fuel must be injected to compensate and prevent the fuel/
air mixture from becoming thin during acceleration. Once the load factor reduces, additional fuel
containing in the fuel film of the intake manifold wall may release again. During deceleration, it is
required to reduce corresponding injection duration.

Motoring or traction operation condition means that power provided by engine in the flywheel is
negative. In this case, the engine friction and pumping losses can be used to decelerate the ve-
hicle. When the engine is in motoring or traction operation condition, the fuel supply is stopped
to reduce fuel consumption and exhaust emission. The more important function is to protect the
catalytic converter.

Once the engine speed reduces to certain fuel-supply-restore engine speed above idling speed,
the fuel system supplies fuel again. Actually, the program in ECU has a range of engine speed re-
storing. They can vary with dynamic parameters such as engine temperature and engine speed.
Through calculation, drop to specified minimum threshold value can be avoided.

Once the injection system supplies fuel again, the system starts using the initial injection pulse for
fuel supply, and then rebuilds oil film in the wall of the intake manifold. After fuel supply restarts,
the torque-dependent control system may increase engine torque slowly and stably (smooth tran-
sition).
2.3.4 Idle control

The engine does not provide torque to the flywheel at idling speed. In order to ensure that the
engine may run stably in as low idling speed as possible. Closed loop idling control system must
maintain balance between generated torque and engine “power loss”. A certain power should be
generated at idling speed to meet load requirement. They include engine crankshaft, valve train
and supportive accessories, such as internal friction of water pump.

ME7 system uses torque value as main control strategy and consider close loop idling speed to
confirm how much output torque of engine is required to keep the desired idling speed at any op-
erating conditions. The output torque may increase with engine speed decreasing and decrease
with engine speed increasing. The system responds new “interference factors” (such as opera-
tion of A/C compressor, or shifting mechanism of automatic transmission) through greater torque.
When engine temperature is low, it is also required to increase torque in order to compensate
greater internal friction losses and/or maintain a higher idle speed. Sum of the output torque re-
quirements is transferred to the torque coordinator which processes and calculates the sum, then
getting corresponding charging density, composition of fuel/air mixture and ignition timing.
2.3.5 lClosed-loop control

Exhaust post treatment in the catalytic converter is an effective method to reduce concentration of
harmful substances in the exhaust. Three-way catalytic converter can reduce hydrocarbon (HC),
carbon monoxide (CO) and nitrogen oxides (NOx) by 98% or more and convert them into water
(H2O), carbon dioxide (CO2) and nitrogen (N2). Such a high efficiency can be achieved only within

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the very narrow ambient range, when the engine excess air coefficient λ=1, lclosed-loop control
target is to ensure gas mixture concentration is within this range.

lThe closed-loop control system can work only when it is equipped with an oxygen sensor. The
oxygen sensor position on the side of three-way catalytic converter monitors oxygen content in
the exhaust. Thin gas mixture λ>(1) generates about 100mzV sensor voltage and strong gas mix-
ture λ<(1) generates about 900mV sensor voltage. When λ=1, the sensor voltage has a transition.
lThe closed-loop control responds the input signal (λ>1 = excessively lean mixture, λ<1 = exces-
sively rich mixture) and then modifies the control variable. Correction factor generated is used as
a multiplier to correct the fuel injection duration.
2.3.6 Evaporative emission control

Because of external radiation heat and oil return heat transferring, the fuel in the fuel tank is heat-
ed to form fuel vapor. Due to limitations by the evaporative emission regulations, vapor containing
large amounts of HC is not allowed to be directly exhausted to the air. In the system, the fuel va-
por is collected in the charcoal canister through guide tubes and blew and washed into the engine
to participate in the combustion process in the proper time. Flow of blew and washed air is gener-
ated through the ECU controlling the canister control valve. The control can work only lwhen the
closed-loop control system is working in closed-loop.
2.3.7 Knock control

Through the knock sensor mounted in a proper position of the engine, the system may detect
characteristic oscillation generated in knock, and transfer it into the electronic signal and then
send it to the ECU for processing. The ECU uses a special processing algorithms and may detect
whether knocking phenomenon in each combustion cycle in each cylinder. Once any knocking is
detected, the knocking closed-loop control will be activated. When risk of knocking disappears,
ignition in the impacted cylinder may gradually restore the preset ignition advance angle.

The knock control threshold good adaptability to different conditions and fuels of different grades.
2.4 System fault diagnosis function introduction

2.4.1 Fault information recording

The electronic control unit continuously monitors the sensor, the actuator, related circuit fault in-
dicator and battery voltage etc., and even the electronic control unit itself, and conduct reliability
inspection and examination for the sensor output signal, the actuator drive signal and internal
signals (such as closed-loop control, coolant temperature, knocking control idling speed control
and battery voltage control etc.) Once it is found that one link has fault or a certain signal is not
reliable, the electronic control unit may set the fault information record in the RAM fault memory.
Fault information record is saved in form of trouble code and then displayed in sequence of fault
occurrence.

The faults can be divided into “stable faults” and “occasional faults” according to occurrence rate
(such as faults caused by open circuit of wire harness or poor contact of connectors).

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Functions diagnosis Electronic Functions diagnosis

control unit
Data acquisition Control command

Sensor Actuator

Engine

Fig. 3-4 Schematic diagram for EFI fault diagnosis

2.4.2 Four fault types

B_mxdfp, the maximum fault, signal exceeds upper limit of normal range.

B_mndfp, the minimum fault, signal exceeds lower limit of normal range.

B_sidfp, signal fault, without signals.

B_npdf, unreasonable fault, with signal, but the signal is unreasonable.

2.4.3 Diagnosis tester connection

This system adopts “K” line communication protocol, and ISO 9141-2 standard diagnosis connec-
tor, see the following Fig. 3-5. The standard diagnostic connector is firmly connected to the engine
wiring harness. #4, #7 and #16 pins are used for standard diagnosis of EMS. Standard diagnostic
connector #4 pin connects the vehicle ground wire; # 7 pin connects # 71 pins, i.e., engine data “K”
Line; # 16 pin connects to the battery anode.

Fig. 3-5 ISO9141-2 standard diagnosis connector

ECU can communicate with external diagnosis tester through “K” line and operate as fol-
lows:

(for each function and diagnosis tester operation, see “ME7 Diagnosis Tester Operation Manual”)

I. Engine parameter display

1. Speed, coolant temperature, throttle openness, ignition advance angle, fuel injection
pulse width, intake pressure, intake temperature, speed, system voltage, fuel injection
correction, canister washing rate, idle air control and oxygen sensor wave form;

2. Target speed, engine relative load, ambient temperature, ignition closing time, evapora-
tor temperature, intake air flow and fuel consumption;

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3. Throttle position sensor signal voltage, coolant temperature sensor signal voltage,
intake air temperature sensor signal voltage, intake pressure sensor signal voltage,
knock sensor 1# pin signal voltage, and knock sensor 2# pin signal voltage.

II. EFI system state display

Anti-theft system state, safety state, programming state, cooling system state, steady working
condition state, dynamic working condition state, emission control state, oxygen sensor state,
idle speed state, MIL state, emergent working condition state, air conditioner state and automatic
transmission/torque request state.

III. Actuator testing function

MIL, fuel pump, air conditioner relay, fan, ignition, fuel injection (single cylinder fuel cut-off).

IV. Speedometer display

Mileage and running time.

V. Version information display

Vehicle identification number (VIN), ECU hardware number, ECU software number.

VI. Fault display

intake pressure sensor, intake temperature sensor, engine coolant temperature sensor, throttle
position sensor, oxygen sensor, oxygen sensor heating circuit, air-fuel ratio correction, each cyl-
inder fuel injector, fuel pump, knock sensor, speed sensor, phase sensor, canister control valve,
cooling fan relay, speed signal, idle speed, idle speed regulator, system voltage, ECU, air condi-
tioner relay, evaporator temperature sensor, MIL.
2.5 Problems related to the project

System features:

Multi-point sequential injection system;

New engine function structure using torque as variable; it is the most compatible with other sys-
tems and so it is very expandable;

New modular software and hardware structure makes excellent portability;

Adopt cylinder-determining signal (phase sensor PG3.8);

Adopt 60-2 tooth signal panel to identify speed signal (speed sensor DG6);

Use stepper motor air control;

Realize idling torque closed-loop control;

Separate knock control for each cylinder (knock sensor KS-1-K);

With functions of heating and protecting the catalytic converter;

With “limp home” function;

With “flashing code” function etc.

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3. Structure, principle and fault analysis for ME7 system parts

3.1 Electronic throttle body

Diagram and pins

Electrical schematic diagram

PIN definition

Signal outout 1

Input voltage +

Motor driving +

Signal outout 2

Motor driving -

Input voltage -

3.2 Intake pressure temperature sensor

Diagram and pins

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Fig. 3-6 Intake pressure and temperature Fig. 3-7 Intake pressure and temperature
sensors sensor circuit diagram

Pin: No. 1 connects to the grounding;

No. 2 is intake temperature signal output;

No. 3 connects to 5V;

No. 4 is intake pressure signal output.

3.2.1 Installation position

This sensor consists of two sensors, i.e. the intake manifold absolute pressure sensor and the in-
take air temperature sensor, mounted on the intake manifold.
3.2.2 Working principle

The intake manifold absolute pressure sensor subassembly consists of a silicon chip. A piece
of pressure diaphragm is etched in the silicon chip. The pressure diaphragm has 4 piezoelectric
resistors; 4 piezoelectric resistors as strain subassembly form a Wheatstone bridge. In addi-
tion to pressure diagram, the silicon chip is integrated with signal processing circuit. The silicon
chip forms a closed reference space with a metal housing. Air absolute pressure in the reference
space is close to zero. Thus one micro-electro-mechanical system forms. Active surface of the sil-
icon chip is subjected to pressure of almost equal to zero. Its back surface is subjected to intake
manifold absolute pressure which is to be measured and can be introduced by a connection pipe.
Silicon chip thickness is only several microns (mm). Therefore, if the absolute pressure of intake
manifold changes, silicon chip will deform mechanically. 4 piezoresistances also deform and the
resistance values change. After the silicon chip signal processing circuit conducts the process,
voltage signal having linear relationship with pressure is formed.

The intake air temperature sensor subassembly is a negative temperature coefficient (NTC) re-
sistor. Resistance varies with the intake air temperature. Now this sensor sends a voltage value
which may indicate intake air temperature change.

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Fig. 3-8 Section drawing of intake manifold absolute pressure and intake temperature

1. Seal ring, 2. Stainless steel bushing, 3PCB plate, 4 sensing element, 5.Case, 6.Pressure
bracket, 7.Welding connection, 8.adhesive connection
3.2.3 Technical characteristic parameter

(1) Limit data

Value
Amount Unit
Minimum Typical Maximum
Withstand supply voltage 16 V
Withstand pressure 500 kPa
Withstand storage temperature -40 +130 °C

(2) Characteristic data

Value
Amount Unit
Minimum Typical Maximum
Range of stress test 20 115 kPa
Operating temperature -40 125 °C
Operating power supply 4.5 5.0 5.5 V
Current when US=5.0V 6.0 9.0 12.5 mA
Load current of output circuit -0.1 0.1 mA
Load resistance to ground or battery 50 kW
Response time 0.2 ms
Weight 27 g

(3) Transfer function of the pressure sensor

UA=(c1 pabs+c0)Us

In the formula, UA = signal output voltage (V)

US = Power voltage (V)

pabs = absolute pressure (kPa)

c0=-9.4/95

c1=0.85/95(1/kPa)

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From the formula, we can tell that at atmospheric pressure, signal output voltage of pressure sen-
sor is close to power supply voltage.

If supply voltage is 5V, the output voltage of signal from the pressure sensor is equal to about 4V
when the throttle is fully open.

(4) Temperature sensor limit data

Storage temperature: -40/+130°C

Carrying capacity at 25°C: 100mW

(5) Performance data of temperature sensor

Operating temperature: -40 / +125°C

Rated voltage: Front resistor 1kW runs at 5V or runs at test current of ≤ 1mA

20°C rated resistance: 2.5 kW ± 5%

Temperature time factor in the air t63, v=6m/s: ≤ 45s

3.2.4 Installation notes

The sensor is designed to be installed in the plane of the engine intake manifold. The pressure
connection pipe and the temperature sensor are protruded to the intake manifold and sealed
against the atmosphere through an O-ring.

If it is mounted on vehicle in a proper manner (taking pressure from the intake manifold; pressure
pipe tilts downward etc), no condensation water will form in the pressure-sensitive elements.

When drilling or fastening the intake manifold, you must comply with instructions provided in the
supplier figure to ensure that the intake manifold can be sealed for a long time and withstand the
erosion of media.

Whether contacting of connector electrical connection is reliable or not is depending on both com-
ponents connectors and quality/size accuracy of the wiring harness and the connector material.
3.2.5 Fault phenomenon and judgment method

• Fault symptom: stalling and poor idling etc.

• General causes: 1. Abnormally high pressure or large reverse current exists in the process of
use; 2. Vacuum components are damaged in the process of repair.

• Repair instructions: Do not punch the vacuum subassemblies by high pressure gas in the
process of repair; When replacing the sensor after finding fault, it is required to carefully
check that the generator output voltage and current is normal.

• Simple measurement methods:

Temperature sensor: (remove the connector) turn a digital multimeter to ohm position; connect
two probes with pins 1# and 2# of the sensor. At 20°C, rated resistance is 2.5kΩ ± 5%. For other
corresponding resistance values, see the above characteristic curve. Simulation method can be
used for measurement. Specific operation is to blow the sensor by a hair dryer (careful not to get
too close). Observe change of sensor resistance. Now resistance should drop.
Pressure sensor part: (connected to the connector) Switch the digital multimeter to "voltage"
position. The black pen is connected to the ground; the red pen respectively connects to #3 and #

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4 pins. At idling, #3 pin should have 5V reference voltage and #4 pin about 1.3V voltage (specific
value is related to vehicle model); at no-load state, slowly open the throttle, and voltage change in
#4 pin does not change much; quickly open the throttle, and voltage of #4 pin can reach approxi-
mately 4V instantaneously (specific value is related to vehicle model), and the drop to approxi-
mately 1.5V (specific value is related to vehicle model).

Fig. 3-9 resistance characteristic curve of intake air temperature sensor NTC
3.3 Coolant temperature sensor

Diagram and pins

Coolant Temp
Sensor

Fig. 3-10 Coolant temperature sensor Fig. 3-11 Coolant temperature sensor circuit
diagram

Pin: this sensor has two pins, which can be interchanged.

3.3.1 Installation position

It is mounted on the engine water outlet.

3.3.2 Working principle

The sensor is a negative temperature coefficient (NTC) resistor. Resistance decreases with cool-
ant temperature increasing, not in linear relationship. Negative temperature coefficient thermistor
is installed on a copper surface, see the following Fig.

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Fig. 3-12 Coolant temperature sensor cross- Fig. 3-13 Coolant temperature sensor char-
sectional view acteristic curve

3.3.3 Technical characteristic parameter

(1) Limit data

Amount Value Unit

Rated voltage Only run in ECU
Rated resistance of 20°C 2.5 ± 5% kW
Operating temperature range -30°C~ +130°C °C
Maximum measurement current through the sensor 1 mA
Permissible vibration acceleration 600 m/s2

(2) Characteristic data

Resistance (kW) Tempera-

S/N Temperature tolerance ± 1°C Temperature tolerance ± 0°C ture
Minimum Maximum Minimum Maximum (°C)
1 8. 16 10. 74 8. 62 10. 28 -10
2 2. 27 2. 73 2. 37 2. 63 +20
3 0. 290 0. 354 0. 299 0. 345 +80

3.3.4 Installation notes

The coolant temperature sensor is mounted on the cylinder body, and the copper heat sleeve
is inserted into the coolant. The sleeve is threaded. Hexagon head in the sleeve can be used to
easily screw the coolant temperature sensor into the threaded hole in the cylinder body. The max-
imum allowed tightening torque is 20Nm.
3.3.5 Fault phenomenon and judgment method

• Fault symptom: hard starting etc.

• General cause: man-made fault.

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• Simple measurement methods:

(Remove the connector) Turn a digital multimeter to ohm position; connect two probes with pins
1# and 2# of the sensor. At 20°C, rated resistance is 2.5kΩ ± 5%. For other corresponding resis-
tance values, see the above characteristic curve. Simulation method can be used for measure-
ment. Specific operation is to place the working part of the sensor into the boiled water (careful
to keep immersion enough long) . Observe change of sensor resistance. Now resistance should
drop to 300Ω-400Ω (specific value depending on water temperature).
3.4 Knock sensor

Diagram and pins

Fig. 3-14 Knock sensor without cables Fig. 3-15 Knock sensor with cables

Knock sensor
Fig. 3-16 Knock sensor circuit diagram Fig. 3-17 Knock sensor cross-sectional view

Pin: No. 1 and 2 connect with ECU; No. 3 connects with the shield.

3.4.1 Installation position

3-cylinder engine is installed between two cylinders; 4-cylinder engine is installed between 2~3
cylinder.
3.4.2 Working principle

The knock sensor is a vibration acceleration sensor, mounted in the engine cylinder block. One
or more knock sensors can be installed. Sensitive element of the sensor is piezoelectric element.
Vibration of the engine block is passed through the mass in the sensor to the piezoelectric crystal.

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Piezoelectric crystal generates voltage in two polar faces due to pressure generated by the vibra-
tion of the mass. Vibration signal is converted into alternative voltage signal before outputting. The
frequency response curve is as shown in the figure below. Since the frequency of vibration signal
caused by the engine knock is much higher than the normal engine vibration signal frequency,
whether it is knock signal or no knock signal can be distinguished after processing the knock sen-
sor signal.

Knock sensor is supplied with or without cable for customers.

Frequency

Fig. 3-18 Knock sensor frequency response curve

3.4.3 Technical characteristic parameter

(1) Limit data

Value
Amount Unit
Minimum Typical Maximum
Working temperature -40 +130 °C

(2) Characteristic data

Amount Value Unit

New sensor sensitivity to 5kHz signal 26 ± 8 mV/g
Linearity between 3 to 15kHz ± 15% of the value 5kHz
Resonance linearity 15 to 39 mV/g
Change during the entire life -17% Max.
Main resonance frequency >20 kHz
Resistance >1 MW
Impedance Capacitance 1200 ± 400 pF
Including cable capacitance 280 ± 60 pF/m
Leakage resistance
4.8 ± 15% MW
(resistance between two output pins of sensor)
Temperature causes change of sensitivity ≤ -0.06 mV/g° K

3.4.4 Installation notes

There is a hole in the middle of knock sensor. It is fastened on cylinder block with a M8 bolt. Alu-
minum cylinder block is fastened by 30mm - long bolt. Cast-iron cylinder block is fastened by
25mm - long bolt. Tightening torque 20 ± 5Nm. Installation position shall make the sensor receive
vibration signals from all cylinders easily. The best installation position of the knock sensor should
be determined by modal analysis of the engine block. Be careful not to allow a variety of liquids,
such as engine oil, coolant, brake fluid and water, have a long time of contact with sensor. Do
not use any type of washer during installation. The metal surface of the sensor must be closely

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against to the cylinder block. When wiring the signal cables of sensors, do not cause resonance
of signal cables in order to avoid breaking. High voltage shall be avoided between pin 1# and 2#
because piezoelectric elements may be damaged.
3.4.5 Fault phenomenon and judgment method

• Fault symptom: poor acceleration etc.

• General cause: A variety of liquids, such as engine oil, coolant, brake fluid and water, have a
long time of contact with sensor, causing corrosion.

• Repair instructions: (refer to installation instructions)

• Simple measurement methods:

(Remove the connector) turn a digital multimeter to ohm position, connect two probes with 1#
and 2#, 1# and 3# pins of the sensor. At room temperature, the resistance value shall be higher
than 1MΩ. Switch the digital multimeter to position "millivolt" and then gently hit the vicinity of the
knock sensor with a small hammer. Now voltage signal should output.
3.5 Oxygen sensor

Diagram and pins

Fig. 3-19 oxygen sensor

Main
relay

Oxygen sensor

Fig. 3-20 oxygen sensor Fig. 3-21 oxygen sensor circuit diagram

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Oxygen sensor is provided with cable. The other end of cable is electric terminal. Electrical termi-
nals of oxygen sensor manufactured by our company have four pins:

No. 1 connects with the positive electrode of heating power source (white);

No. 2 connects with the negative electrode of heating power source (white);

No. 3 connects with negative electrode of the signal (grey);

No. 4 connects with positive electrode of the signal (black).

3.5.1 Installation position

Installed on front end of exhaust pipe.

3.5.2 Working principle

Oxygen sensor sensing subassembly is a porous ceramic tube. External side of the tube wall is
surrounded by the engine exhaust and internal side connects with air. The sensor ceramic wall is
a solid electrolyte, containing electric heating tube. See figure 3-17.

The oxygen sensor works through converting the ion concentration difference between inside and
outside of the sensing ceramic tube into the voltage signal output. When sensing ceramic tube
temperature reaches 350°C, it has solid electrolyte characteristics. Because of its special mate-
rial, oxygen ions can freely pass through the ceramic tube. Through this characteristics,

Concentration difference is converted into an electrical potential difference, thereby forming an

electric signal before outputting. If fuel/air mixture is rather rich, Oxygen ion concentration differ-
ence between the inside and outside of the ceramic tube is rather big and the potential difference
is high, and now lots of oxygen ions transfer to outside from inside, and output voltage is rather
high (close to 800mV-1000mV); if fuel/air mixture is rather rich, oxygen ion concentration differ-
ence between the inside and outside of the ceramic tube is rather small and the potential differ-
ence is low, and now only a small amount of oxygen ions transfer to outside from inside, and out-
put voltage is rather low (close to 100mV) Signal voltage changes suddenly at theoretical air-fuel
ratio (λ=1). See the following Fig.
Output voltage

Excessive Air Coefficient

Fig. 3-22 600C ° Oxygen sensor characteristic curve

3.5.3 Technical characteristic parameter

(1) Limit data

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Value
Amount Mini- Maxi- Unit
Typical
mum mum
Storage temperature -40 +100 °C
Ceramic tube end 200 850 °C
Hexagon head of housing ≤ 570 °C
Working
Temperature Cable metal buckles and connection
≤ 250 °C
cable
Connector ≤ 120 °C

Maximum permissible Exhaust in the ceramic tube end 930 °C

temperature when
heating subassembly is
connected through (up
to 10 minutes at a time, Hexagon head of housing 630 °C
accumulated up to 40
hours at most) Cable metal buckles and connection
280 °C
cable
Permissible temperature changing rate in the ceramic tube ≤ 100 K/s
Allowable temperature of ceramic subassembly when condensa-
≤ 350 °C
tion water exists in the exhaust side
Random vibration (Peak) ≤ 800 m/s2
Simple harmonic motion
Permission vibration of ≤ 0.3 mm
(Vibration displacement)
housing
Simple harmonic motion
≤ 300 m/s2
(Vibration acceleration)
Absolute
Continuous DC current at 350°C mA
value ≤ 10
Exhaust temperature³350°C, at f³1Hz
± 20 mA
Maximum continuous AC current
Unleaded gasoline, or permissible lead con-
Permissible fuel additive
tent reaches to 0.15g/L
Permissible values and data must be con-
Engine oil consumption and combustion firmed by customers in the proper size of
tests. Reference value: ≤ 0.7L/1000km

(2) Characteristic data

Amount New After 250-hour bench test

Exhaust temperature when character-
350°C 850°C 350°C 850°C
istics data are formed
λ=0.97(CO=1%)
840 ± 70 710 ± 70 840 ± 80 710 ± 70
Sensing element voltage (mV)
λ=1.1
20 ± 50 50 ± 30 20 ± 50 40 ± 40
Sensing element voltage (mV)
Internal resistance of sensor elements
≤ 1. 0 ≤ 0. 1 ≤ 1. 5 ≤ 0. 3
(kW)
Response time (ms)
<200 <200 <400 <400
(600mV to 300mV)
Response time (ms)
<200 <200 <400 <400
(300mV to 600mV)

(3) Electric data of the sensor

Amount Value Unit

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Insulation resistance At room temperature, disconnect heating element ≥ 30 MW

between heating the new Exhaust temperature350°C ≥ 10 MW
sensor subassembly and
the sensor connector Exhaust temperature850°C ≥ 100 kW
Rated voltage 12 V
Continuous operating voltage 12 to 14 V
Keep working voltage for 1% total life at most (Exhaust
On the plug 15 V
gas temperature ≤ 850°C)
Power supply voltage
Working voltage retaining 75s at most
24 V
(Exhaust temperature ≤ 350°C)
Test voltage 13 V
Heating power when working voltage is 13V and in reaching thermal equilibrium
12 W
(Exhaust gas temperature 350°C, exhaust flow about 0.7 m/s)
Heating current when working voltage is 13V and in reaching thermal equilibrium
5 A
(Exhaust gas temperature 350°C, exhaust flow about 0.7 m/s)
Heating circuit fuse 8 A

(4) Service life

Life of the oxygen sensor is related with content of lead in gasoline; see the table below for de-
tails.

Lead content in gasoline (g/L) Life (km)

≤ 0.6 30000
≤ 0.4 50000
≤ 0.15 80000
≤ 0.005 (unleaded gasoline) 160000

3.5.4 Installation notes

• Oxygen sensor shall be installed on exhaust pipe and represent exhaust gas and meet
specified temperature value. Installation site is close to the engine. Threads are provided on
exhaust pipe to screw in oxygen sensor, see the following Fig.

Fig. 3-23 Installation position of oxygen sensor

• Installation type of oxygen sensor

Oxygen sensor shall be installed with an included angle10° to horizontal plane. The sensor tip

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is downwards to avoid accumulating condensate water between the sensor housing and sensing
ceramic tube, see the following Fig..

Fig. 3-24 Oxygen sensor installation type

• Exhaust pipe requirements: heat exhaust pipe in the area in front of oxygen sensor immedi-
ately. If possible, exhaust pipe shall be designed to be inclined downwards to avoid conden-
sate water from accumulating in front of the sensor.

• Do not make metal ring of the cable on the side of oxygen sensor heat inappropriately, espe-
cially after the engine stops.

• Do not use washing fluid, oily liquid or volatile solid on oxygen sensor plug.

• Threads of oxygen sensor are M18�1.5.

• Hexagonal head wrench dimension of oxygen sensor is 22-0.33.

• Tightening torque of oxygen sensor is 40~60Nm.

3.5.5 Fault phenomenon and judgment method

• Fault symptom: improper idling and acceleration; emission exceeds standard value, fuel con-
sumption is too large.

• General cause: 1. Moisture enters inside of the sensor; temperature changes suddenly;
probe is broken; 2. oxygen sensor "poisoning". (Pb,S,Br,Si)

• Repair instructions: Do not use cleaning fluid, oily liquid and volatile solids on the oxygen
sensor during repair.

• Simple measurement methods:

(Remove the connector) Turn a digital multimeter to ohm position; connect two probes with
1# (white) and 2# (white) pins of the sensor. The resistance value is 1~6 Wat room tempera-
ture.

(connect the connector) At idle speed, when oxygen sensor reaches to working temperature
350°C, turn a digital multimeter to DC voltage position; connect two probes with 3# (grey)
and 4# (black) pins of the sensor. Now, the voltage fluctuates between 0.1-0.9V quickly.
3. 6 Speed sensor (only for the system without distributor block)

Diagram and pins

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Speed sensor

Fig. 3-25 Speed sensor Fig. 3-26 Circuit diagram of speed sensor

Fig. 3-27 Speed sensor section

3.6.1 Installation position

On the flywheel surface on the back of engine.

3.6.2 Working principle

Speed sensor and pulse wheel are used in ignition system without distributor block to provide en-
gine speed information and crankshaft TDC information. Speed sensor consists of one permanent
magnet and coils outside the magnet. Pulse wheel is a fluted disc. Originally, it has 60 teeth, but
two teeth are vacant. Pulse disc is mounted on the crankshaft, rotating with crankshaft rotation.
When teeth top is passing near the end of speed sensor, pulse wheel made of ferromagnetic ma-
terial cuts magnetic line of force in permanent magnet. Induced voltage is generated in the coil,
which is output as speed signal.
3.6.3 Technical characteristic parameter

(1) Limit data

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Value
Amount Unit
Minimum Typical Maximum
Coil area -40 +150 °C
Transition area Mixed Mixed °C
Conducting wire area -40 +120 °C
Storage temperature -20 +50 °C
The tempera- Ambient temperature when it does
-40 +120 °C
ture endured not run
by PUR wire Long-term environmental tempera-
speed sensor -40 +120 °C
ture when it is running
(see the fol- Short-term environ- 150 hours +150 °C
lowing Fig.) mental temperature
when it is running 380 hours +140 °C
150 hours +150 °C
Within use life in
380 hours +140 °C
conducting wire area
1130 hours +130 °C
Coil area -40 +150 °C
Transition area Mixed Mixed °C
Conducting wire area -40 +130 °C
Storage temperature -20 +50 °C
H&S wire Ambient temperature when it does
speed sensor -40 +130 °C
not run
endured by
(see the fol- Long-term environmental tempera-
-40 +130 °C
lowing Fig.) ture when it is running
Short-term environmental tempera-
+150 °C
ture when it is running
Within use life in 500 hours +150 °C
conducting wire area 200 hours +160 °C
Vibration resistant ability in 20 to 71Hz Acceleration ≥ 40 m/s2
each plane in 168 hours 71 to 220Hz Amplitude ≥ 0.2 mm
Permissible magnetic field strength in opposite direc-
≤2 kA/m
tion of external magnetic field
Insulation resistance (10s, New state ≥1 MW
test voltage 100V) End of use life ≥ 100 kW
Withstand voltage (1-3 seconds, 1200V AC) No breakdown

Conducting
wire area

Transition area

Coil area

Fig. 3-28 three temperature zones of speed sensor

(2) Characteristic data

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Value
Amount Unit
Minimum Typical Maximum
Resistance at room temperature 20°C 731 860 989 W
Inductance 310 370 430 mH
Output voltage when the crankshaft is
>1650 mV
at 416 rpm

3.6.4 Installation notes

• Before speed sensor is required to be installed on a vehicle or a testing device, it can be

taken out from the packaging box.

• Speed sensor is installed by pressing-in method, not hammering.

• It is suggested to fasten the speed sensor with partially-sealed bolt M6´12.

• Tightening torque8 ± 2Nm.

• Air gap between speed sensor and pulse wheel tooth top: 0.8~1.2mm.

• Dimension d (see the following Fig.): 4.7mm.

Fig. 3-29 Speed sensor installation

3.6.5 Fault phenomenon and judgment method

• Fault symptom: Fail to start etc.

• General cause: man-made fault.

• Repair instructions: Install it in pressing instead of knocking by hammer in the process of re-
pair.

• Simple measurement methods:

(Remove the connector) turn a digital multimeter to ohm position; connect two probes with 2# and
3# pins of the sensor. At 20°C, rated resistance is 860Ω ± 10%.

(Connect the connector)Turn a digital multimeter to AC voltage position; connect two probes with
2# and 3# pins of the sensor. Start the engine, and voltage shall be output. (recommended to
check it using a vehicular oscilloscope)

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Fig. 3-30 Test waveform diagram

3.7 Phase sensor (only used for the system without distributor block)

Diagram and pins

Ground point

Phase sensor

Main relay

Fig. 3-31 Phase sensor Fig. 3-32 Phase sensor circuit diagram

Pin: mark “1” indicates grounding;

Mark “2” indicates signal output;

Mark “3” indicates connection to positive electrode of the power.

3.7.1 Installation position

Camshaft cover.
3.7.2 Working principle

This sensor is used for distributorless electrical devices and works with the pulse disc sensor to
provide ECU with crankshaft phase information, i.e., compression top dead point and exhaust
bottom dead point.

This sensor applies Hall principle. The sensor is made according to a fact that Hall voltage is im-
pacted by changed magnetic field induction intensity.

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B Hall sensor principle

When half of current IS goes through a semi-

conductor thin slice, current may generate
one Hall voltage UH in the right turn direction
which is proportional to magnetic induction
B (perpendicular to the current IS) and cur-
rent IS. Hall voltage is impacted by changed
magnetic field induction intensity B.

I
UH

Fig. 3-33 Hall effect principle diagram

Rotation direction

Phase signal wheel

Output signal

Fig. 3-34 Operation schematic diagram for Fig. 3-35 Operation schematic diagram for
phase sensor (I) phase sensor (II)

3.7.3 Technical characteristic parameter

Limit data

Value
Amount Maxi- Unit
Minimum Typical
mum
Ambient temperature -30 +130 °C
Installation clearance 0.5 1.5 mm
Supply voltage 4.5 24 V

3.7.4 Installation notes

The sensor housing has only one hole used for fastening.
3.7.5 Fault phenomenon and judgment method

• Fault symptom: Excessive emissions and increased fuel consumption.

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• General cause: man-made fault.

• Simple measurement methods:

(Connect the connector) press start button, and do not start the engine, turn a digital multimeter to
DC voltage position, connect two probes with 3#, 1# pins of the sensor, make sure 12V reference
voltage exists. Start the engine, and now check if 2# pin signal is normal with a vehicle oscillo-
scope.
3.8 Electronic controller unit

Fig. 3-36 ECU outline diagram

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Power supply > Motronic-IC LSS > Fuel injector 1

Start button > 6 x 2,2A > Fuel injector 2

5V power supply. 1 < 70V > Fuel injector 3

5V power supply. 2 < 80C167CR > Fuel injector 4

Crankshaft Hall sensor > > Reserved

Main relay < > Reserved

Diagnosis K-line <>

2 x 2,7A > Intake phase variable

Fuel pump > Analog signal input 45V > Exhaust phase variable

oxygen sensor (front) >

Supply voltage > 2 x 2,2A > Canister control valve

Water temperature > 45V > Reserved

Intake air temperature: > FLASH 1MB

Accelerator pedal signal 1 > 4 x 0,6A > Fuel pump relay

Accelerator pedal signal 2 > 40V > A/C compressor relay

Throttle position signal 1 > > Cooling fan 1

Throttle position signal 2 > RAM 32KB > Cooling fan 2

A/C pressure: >

Engine oil temperature > 4 x 0,6A > MIL

Oxygen sensor(rear) > 45V > SVS lamp

Power steering > PORT > Reserved

Air conditioner temperature > Expander > Reserved

Reserved >

Reserved > 3 x 50 mA > TN

> Reserved

Cam shaft signal 2 > Digital signal input > Reserved

Cam shaft signal 1 > EEPROM

Generator voltage > 1024Byte H bridge > Electronic throttle

Electric switch 1 > driver > Electronic throttle

Electric switch 2 >

Brake switch > Ign. Driver > Ignition coil

Brake lamp switch > 68HC05

Air conditioner request signal > Ign. Driver > Ignition coil

Clutch switch >

Anti-theft device > MOSFET > Front oxygen heating

Air conditioner compressor >

Knock sensor 1 > Motronic-IC

Knock sensor 2 >

Anti-theft device <> MUX

CAN bus high <> CAN Bus

CAN bus low <> Driver

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3.8.1 Installation position

Side of the passenger compartment.

3.8.2 Working principle

(1) Function

• Multi-point sequential injection

• Control ignition

• Air inflow control

• Knock control

• Provide sensor power supply: 5V/100mA

• λClosed-loop control, with self-adaption

• Control canister control valve

• Air conditioning switch

• Engine malfunction indicator

• Fuel quantitative correction amount

• Engine speed signal output (TN signal)

• Vehicle speed signal input

• Fault self-diagnosis

• Receive engine load signal

And so on.

(2) ECU pin definitions:

Limit data

Value
Amount Unit
Minimum Typical Maximum
Normal operation 9.0 16.0 V
Battery voltage
Limited function 6.0 to 9.0 16.0 to 18.0 V
Limit and time withstand- Maintain some functions,
26.0V 60 s
ing battery overvoltage and perform fault diagnosis
Working temperature -40 +70 °C
Storage temperature -40 +90 °C

3.8.4 Installation notes

• Pay attention to electrostatic protection during installation

• Pay attention to the protection of connector pins

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3.8.5 Fault phenomenon and judgment method

• Fault symptom: unstable idle, improper acceleration, fail to start, too high idle, excessive ex-
haust, difficult start, A/C failure, injector control failure, and stalling.

• General cause: 1. Electrical overload caused by the external devices made the internal parts
in ECU burn, and consequently leading to failure; 2. Water ingress into ECU cause corrosion
of circuit board.

• Repair instructions: 1. Do not arbitrarily remove the ECU in the process of repair; 2. Remove
the battery terminal posts and wait more than 1 minute before removal of ECU; 3. Before
welding, ECU must be removed, and then place the ECU in a proper position after removal; 4.
Do not additionally mount any line on the connection line of the ECU.

• Simple measurement methods:

1. (Connect the connector) Read engine fault record through engine data line K;

2. (Remove the connector) Check that the ECU connection cables are in good condition. Pay
attention to check that ECU power supply cable and grounding line are in good condition;

3. Check that the external sensors work normally, and that the output signal is reliable and that
the line is in good condition;

4. Check that the actuator works normally, and that the line is in good condition;

5. Replace the ECU at last and conduct a test

3.9 Electric fuel pump EKP13.6 type

Diagram and pins

Fuel Pump Relay

Fuel Pump
Main relay

Battery

Fig. 3-37 Electric fuel pump Fig. 3-38 Electric fuel pump circuit diagram

Pin: electric fuel pump has two pins, which connect with fuel pump relay. There are “+” and “-”
marks on fuel pump cases near two pins, which represent connecting positive and negative elec-
trodes, respectively.

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3.9.1 Installation position

In the fuel tank.

3.9.2 Working principle

Electric fuel pump consists of DC motor, vane pump and end cover (integrated with check valve,
relief valve and anti-electromagnetic interference elements). See the following Fig..

The pump and the electric motor are coaxially mounted, and closed in the same housing. Gaso-
line is full in the surrounding of the pump and electric motor in the housing. Use fuel for cooling
and lubrication. The battery supplies power to the electric fuel pump through the fuel pump relay
which just can have the electric fuel pump turn on only when in starting or the engine is running.
When the engine stops running due to an accident, the fuel pump may automatically stop.

1. Oil pump cover

2. Electric motor
3. Oil channel
4. Vane pump

Fig. 3-39 Cross-sectional view of electric fuel pump

The maximum pressure at the outlet of electric fuel pump is determined by relief valve, between
450~650kPa. This system adopts no fuel return system. The pressure of the whole fuel system is
determined by fuel pressure regulator. Normally, it is 350kPa.

According to the requirements of the engine, electric fuel pump can have different flow rate. In or-
der to facilitate production, EKP13 series of electric fuel pump of the same structure adjusts motor
speed by adjusting turns of coil to adjust flow rate. Therefore, do not install electric fuel pump of
one vehicle onto the other vehicle.
3.9.3 Technical characteristic parameter

(1) Limit data

Value
Amount Maxi- Unit
Minimum Typical
mum
Working voltage 8 14 V (DC)
System pressure 350 kPa
Outlet pressure 450 650 kPa
Ambient temperature
-40 +80 °C
(Suitable for storage and transport)
Permissible fuel temperature -30 +70 °C
Permissible vibration acceleration 20 m/s2

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(2) Characteristic data

Flow rate of electric fuel pump in a given fuel supply pressure is proportional to voltage. Vehicle
plant adopts different fuel pumps.
3.9.4 Installation notes

The electric fuel pump should be stored in sealed original packing box. After being mounted in the
vehicle, the maximum permissible storage time is 6-months; as spare part, it can be stored for 4
years at most. If exceed this storage period, have the manufacturer re-check performance data of
fuel pump. Measures should be taken in the storage place to protect the fuel pump against atmo-
sphere. Original packaging should not be damaged during the storage.

EKP13 series electric fuel pump is used for fuel tank. When installing fuel pump, filter screen with
less than 60m meshes or agreed by the customer shall be installed at filler opening. Please pay
attention to prevent fuel ejected from the vent oil from spraying over the oil inlet filter screen, the
pump holder or the fuel tank wall. To be careful when handling the oil pump. Firstly, it is necessary
to protect the oil inlet filter from loading and impacting. The oil pump should be carefully removed
from the plastic packaging material only when it is ready for installation. Before installing fuel
pump, protection cover can be taken away. Never take away the inlet filter screen. Foreign matter
entering the fuel pump inlet or filter screen may cause damage of the fuel pump.

Pay attention to keep oil pipes clean when mounting them. Always keep inside of oil pipe clean.
Please use new oil pipe clips. Make sure that the oil pipe clips are in correct position; please com-
ply with methods recommended by the manufacturer.

Do not hold the oil pump in the oil pipe or the inlet filter screen.

Do not run the fuel pump in dry state in order to avoid damage of fuel pump. Do not use damaged
fuel pump or any fuel pump which was fallen to the ground. After the fuel tank falls to the ground,
you should replace the fuel pump in the fuel tank.

Do not apply any force on fuel inlet plate. No mechanical stress at filleting is allowed. Clamp fuel
pump according to specified range, see the following Fig.

Fuel pump clamping

tolerance range

No mechanical stress at
filleting is allowed.

Fig. 3-40 Fuel pump clamping tolerance range

If product needs to be returned to the manufacturer, please return supply order, check sheet and
packaging label together. Fuel pump returned must be packaged in accordance with methods
specified. If fuel pump has been used, please clean it by test solution and dry it in the air. Do not
blow-dry fuel pump. In consideration of safety, we do not receive fuel pump containing fuel.

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3.9.5 Fault phenomenon and judgment method

• Fault symptom: Big operation noise, poor acceleration, failure in starting (hard to start) etc.

• General cause: Use of poor quality fuel results in: 1. Glial accumulation formed an insulating
layer; 2. Oil pump bushing locks up the armature; 3 Oil level sensor subassembly is corrod-
ed.

• Maintenance notes: 1. According to the requirements of the engine, electric fuel pump can
have different flow rates. Although the outline is the same, fuel pump that is installed may be
not appropriate. Part number for fuel pump used during the course of maintenance shall be
the same as original one. Do not confuse them; 2. In order to avoid damaging fuel pump, do
not run it in a dry state for a long time. 3. If it is necessary to replace fuel pump, please wash
fuel tank and pipe, and replace fuel filter at the same time.

• Simple measurement methods:

(Remove the connector) Turn a digital multimeter to ohm position; connect two probes with two
pins of fuel pump, measure internal resistance. It is not zero or infinite (i.e., not short circuit and
open circuit).

(Connect the connector) connect fuel pressure gauge with fuel inlet pipe, start the engine, check
if fuel pump works; if it does not run, check if “+” pin has power voltage; if it runs, at idle speed,
check if fuel pressure is about 350kPa; step on the accelerator until the engine speed reaches
2500rpm, and check if fuel pressure is about 350kPa.
3. 10 Electromagnetic fuel injector

Diagram and pins

Connect with the

main relay

Cylinder 1 Cylinder 2 Cylinder 3 Cylinder 4

Fuel injector

Fig. 3-42 Electromagnetic fuel injector circuit

Fig. 3-41 Electromagnetic fuel injector diagram

Pin: each fuel injector has two pins. “+” on the side of case is connected with pin 87# on output
end of main relay; the other is connected with pins 27, 6, 7 and 47 of ECU.

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Fig. 3-43 Section view of electromagnetic

Fig. 3-44 Fuel injector of fuel distribution pipe
fuel injector

3.10.1 Installation position

In the intake manifold near the intake valve.

3.10.2 Working principle

ECU sends electrical pulse to the injector coil, forming magnetic force. When the magnetic force
raises to overcome joint resultant of return spring pressure, needle valve gravity and friction force,
the needle valve starts to raise and the injection process begins. When the fuel injection pulse is
cut off, the pressure of the return spring makes the valve close again.

• EV6 type electromagnetic fuel injector:

• Long and standard types according to the length

• According to spraying shapes, B type (single hole and single beam), C type (four-hole
taper) and E type (four holes and double beam)

• Model selection is determined according to engine and intake manifold structure.

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3.10.3 Technical characteristic parameter

(1) Limit data

Value
Amount Maxi- Unit
Minimum Typical
mum
Storage temperature (original packaging) -40 +70 °C
Permissible temperature of injector in the car
+140 °C
(when it is not at work)
Continuous -40 +110 °C
Working temperature of Short time (approxi-
injector mately 3 minutes) after +130 °C
hot start
Injector inlet Continuous +70 °C
Fuel permissive tem- Short time (approximate-
perature +100 °C
ly 3 minutes)
Compared with deviation at 20°C, fuel flow can
-40 +45 °C
reach 5% of the temperature.
Permissible leakage of O-ring at range of -35 to Fuel is allowable to be wet in the area of O-ring, but
-40°C dripping is not allowed.
Maximum permissible vibration acceleration (peak) 400 m/s2
Supply voltage 6 16 V
Insulation resistance 1 MW
Bearable internal fuel pressure 1100 kPa
Bearable bending stress 6 Nm
Bearable axial stress 600 N

(2) Characteristic data

Value
Amount Maxi- Unit
Minimum Typical
mum
Working pressure (pressure difference) 350 kPa
Injector resistance at 20° 11 17 W

(3) Allowable fuel

The Injector can only use fuel specified in national standard of the People’s Republic of China GB
17930-1999 Unleaded Gasoline for Vehicle Use and national environmental standards GWKB
1-1999 Hazardous Materials Control Standard for Motor Vehicle Gasoline. What needs to be
noted is that gasoline will be degraded after a long time of storage. Especially in case of taxi
equipped with dual-fuel engine (LPG and gasoline), LPG is used as fuel for a long time and gaso-
line is used for starting so that the daily consumption of gasoline is very little. But fuel pump runs
a long time, therefore the fuel tank temperature is rather high. If gasoline is stored in the car fuel
tank, gasoline is easily oxidized and degraded, even leading to block or damage of injector
3.10.4 Installation notes

• Confirm BOSCH trademark and product number.

• One fuel injector has a special plug. Do not mix them.

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• For easy installation, it is recommended to smear clean Silicon-free engine oil on the surface
of the upper O-ring which connects with the fuel distributing pipes. Be careful not to let the
engine oil contaminate inside of the injector or the injector nozzle orifice.

• Mount the injector in direction perpendicular to the injector seat and then fasten the fuel in-
jector on the injector seat by clips. Note:

1. The injector clips are grouped in locating manner by axially locating clip and radially lo-
cating clip. Do not confuse them.

2. For installation of injector which requires axial locating, it is required to ensure that
the clipping mouth in the middle of clip is completely buckled into the groove and the
groove in the both side of the clip should be buckled into the edge of the injector seat.

3. When installing the fuel injector with axial and radial locating requirements, both axial
and radial locating clips should be used to locate the locating block of the fuel injector
and the fuel injector seat locating pin respectively in the corresponding groove in the
locating clips.

4. If the fuel injector has two grooves, do not make a mistake in buckling. Refer to the
mounting position of original parts.

• Installation of fuel injector can be carried out by hands. Do not knock the fuel injector by
hammer.

• O-ring should be replaced in removing and re-mounting the fuel injector. Do not damage the
sealing surface of the injector now.

• Do not pull out the supporting washer of O-ring from the fuel injector. Be careful to avoid
damage of fuel ingress end of the fuel injector, O-ring, supporting ring, the nozzle orifice
plate and the electrical plug during installation. Do not use it any more if damaged.

• Inspect and test air tightness of the fuel distribution pipe after the injector is installed. It is ac-
ceptable if no leakage is found.

• Faulty parts should be removed by hands. Firstly remove the injector clips and then pull out
the injector from the injector seat. After removal, make sure that the fuel injector seat is clean
and no contamination is caused.
3.10.5 Fault phenomenon and judgment method

• Fault symptom: Improper idling, poor acceleration, failure in starting (hard to start) etc.

• General cause: lack of maintenance, lead to occurrence of the glial accumulation inside the
injector, consequently resulting in failure.

• Repair instructions: (refer to installation instructions)

• Simple measurement methods:

(Remove the connector) Turn a digital multimeter to ohm position; connect two probes with two
pins of fuel injector. At 20°C, rated resistance is 11-17Ω.

Recommendation: Clean the fuel injector cleaning thoroughly by special cleaning analyzer
each 20,000 km.

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3. 11 Ignition coil (used for 4-cylinder engine without distributor block)

Diagram and pins

Engine

Battery
cathode Primary
Secondary

Control
signal

Fig. 3-45 Independent live wire coil Fig. 3-46 Independent coil circuit diagram

Definition of pins:

Cylinder #1-4 ignition coil

Low voltage side: Primary winding pin of coil #1 connects with main relay 87#;

Primary winding pin of coil #2 connects with pin 5# of ECU;

High voltage side: terminal posts of two secondary windings connect with spark plugs of engine
cylinders of the same name through distributed live wire.

Cylinder #2-3 ignition coil

Low voltage side: Primary winding pin of coil #1 connects with main relay 87#;

Primary winding pin of coil #2 connects with pin 2# of ECU;

High voltage side: terminal posts of two secondary windings connect with spark plugs of engine
cylinders of the same name through distributed live wire.
3.11.1 Installation position

On the engine.
3.11.2 Working principle

Ignition coil consists of primary winding, secondary winding and housing. When grounding chan-
nel of one primary winding is connected through, the primary winding is charging. Once the ECU
cuts off the primary winding circuit, the charging stops and simultaneously senses high voltage in
the secondary winding to make the spark plug discharge electricity.
3.11.3 Fault phenomenon and judgment method

• Fault symptom: Fail to start etc.

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• General cause: Excessively high current cause burning; or damage is resulted from external
force.

• Repair instructions: Do not test ignition function by "short-circuit fire test" method. Otherwise
the electronic controller will be damaged.

• Simple measurement methods:

(Remove the connector) switch the digital multimeter to "Ohm" position; have two probe pens
connect two pins of secondary winding. At 20 °C, the resistance value should be approximately
0.70~ 0.90Ω; resistance of the secondary winding should be 9.68-12.32kΩ.
3.12 Canister control valve

Diagram and pins

Mainr

Canister control valve

Fig. 3-48 Canister control valve TEV-2 circuit

Fig. 3-47 Canister control valve TEV-2
diagram

Pin: canister control valve has two pins. One pin is connected with 87# pin of main relay output
end, and the other pin is connected with pin 46# of ECU.
3.12.1 Installation position

On canister – intake manifold vacuum pipe.

3.12.2 Working principle

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1. Come from fuel

tank
2. Canister
3. Atmosphere
4 Canister control
valve
5. Go to intake
manifold
6. Throttle valve
△ P is difference between environmental pressures
PU and intake manifold pressure PS

Fig. 3-49 Canister control valve cross-sec- Fig. 3-50 Canister control valve installation
tional view diagram

Canister control valve consists of magnetic coil, armature and valve. The inlet is fitted with a filter
screen. On the one hand, airflow going through the canister control valve is related to the duty
ratio which is output to the canister control valve electric pulse by ECU; on the other hand, it is re-
lated to pressure difference between the canister control valve inlet and outlet. When no electrical
pulse is detected, the canister control valve is closed.

Different types of canister control valves have different flowrate at 100% duty ratio, i.e., at fully
open. The following Fig. shows two typical flow curves. As shown in figure, at the same pressure
difference of 200mbar, flowrate of A type and B type canister control valve is 3.0m3/h and 2.0m3/
h respectively when they are at full open. (B type is used in this project)

A Type

B Type
Flowrate

Pressure difference

Fig. 3-51 Canister control valve flowrate diagram

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3.12.3 Technical characteristic parameter

(1) Limit data

Value
Amount Maxi- Unit
Minimum Typical
mum
Working voltage 9 16 V
1 minute overvoltage 22 V
Minimum start-up voltage 7 V
Minimum voltage drop 1.0 V
Permissible operating temperature -30 +120 °C
Short-term permissible operating temperature +130 °C
Permissible storage temperature -40 +130 °C
Bearable pressure difference between inlet and
800 mbar
outlet
8
Permissible switching times 10
Permissible vibration acceleration specified in the
300 m/s2
product label
Leakage amount when pressure difference is
0.002 m3/h
400mbar

(2) Characteristic data

Value
Amount Maxi- Unit
Minimum Typical
mum
Rated voltage 13.5 V
+20°C resistance 26 W
Current under rated voltage 0.5 A
Frequency of control pulse 30 Hz
Typical A type 7 ms
Controlling pulse width B Type 6 ms
Flowrate when differential pres- A type 2.7 3.0 3.3 m3/h
sure = 200mbar and duty ratio
=100% B Type 1.7 2.0 2.3 m3/h

3.12.4 Installation notes

See figure 3-53 for connection of canister control valve, canister and intake manifold.

• In order to avoid passing solid sound, it is recommended to have the canister control valve
mount on the hose, hanging in the air.

• Air flowing direction must be consistent with rules during installation.

• Proper measures such as filtering and purification must be taken to prevent foreign matters
(such as particles) from entering the canister or hose from going into the canister control
valve.

• It is recommended to mount appropriate protective filter (mesh size <50mm) on the canister
outlet.

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3.12.5 Fault phenomenon and judgment method

• Fault symptom: Functions are lost etc.

• General cause: poor Foreign matter ingress into the valve cause corrosion or poor sealing.

• Repair instructions: 1. Air flowing direction must be consistent with rules during installation;
2. Please check canister can condition if it is required to replace the control valve because it
is found that the black particles in the valve body cause failure of control valve; 3. Try to pre-
vent water or oil from entering the valve in the process of repair; 4. In order to avoid passing
solid sound, it is recommended to have the canister control valve mount on the hose, hang-
ing in the air.

• Simple measurement methods:

(Remove the connector) Switch the digital multimeter to "Ohm" position; have two probe pens
connect two pins of the canister control valve. At 20 °C, rated resistance value should be approxi-
mately 22~30Ω.
3.13 Fuel pressure regulator

Simple diagram

Fig. 3-53 Section view for fuel pressure regu-

Fig. 3-52 Fuel pressure regulator
lator

3.13.1 Installation position

In the fuel pressure regulator seat.

3.13.2 Working principle

As shown in 3-56, a flexible film made of rubber-fiber separates fuel pressure regulator into up-
per and lower chambers. Upper chamber goes to atmosphere. There is a spring in upper cham-
ber. Lower chamber is full of fuel that comes from fuel openings around the bottom of pressure
regulator. Fuel pressure is applied below the film, and atmosphere pressure and spring force are
applied above the film. The film can be deformed to drive valve seat to open or close the valve.
But, because the deformation is very small, applied force of the spring remains. Therefore, the

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valve ON/OFF is determined by the difference between fuel pressure in lower chamber and at-
mosphere pressure. Supposing the valve is closed, fuel pressure rises, leading to pressure dif-
ference increase in upper and lower chambers. Finally, the film is ejected by fuel pressure and
the valve is opened. Fuel returns to fuel tank through fuel return opening in the center of pressure
regulator. Fuel pressure decreases until the valve is closed. So, when working conditions of the
engine changes, the difference between fuel system pressure and atmosphere pressure remains
unchanged.
3.13.3 Technical characteristic parameter

(1) Limit data

Value
Amount Mini- Maxi- Unit
Typical
mum mum
Leaking flow rate at pressure difference 280kPa 9 cm3/min
Permissible temperature of continuous working -40 +80 °C
Maximum permissible temperature of fuel +80 °C
At -30°C, maximum permissible pressure drifting (re-
-2% +5%
versible)
At +80°C, maximum permissible pressure drifting (re-
-5% +2%
versible)
Maximum permissible acceleration peak 100 m/s2
Maximum permissible pressure pulse value 100 kPa

(2) Characteristic data

Value
Amount Maxi- Unit
Minimum Typical
mum
Rated pressure difference when Q=80 l/h 350 kPa
Working pressure change when flow rate is between
17.5 kPa
15 and 140 l/h
Flow range 10 220 L/h
Gradient of characteristics curve 0.14 kPa/ L/h

(3) Fuel requirements

Fuel pressure regulator is applicable to the fuel specified by China National Standard GB 17930-
1999

Lead-free Gasoline for Vehicles and National Environment Protection Standard GWKB 1-1999
Hazardous Substance Control Standard for Vehicle Gasoline.

Fuel pressure regulator is also applicable to gasoline containing less than 15% carbinol or etha-
nol.

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3.13.4 Installation notes

• Immerse O ring in clean and free-ketonic engine oil or other lubricating oil approved by
BOSCH.

• When installing and dismantling, do not deform pressure regulating valve.

• When dismantling or reinstalling pressure regulating valve, a new O ring shall be used. If
pressure regulating valve bears more than 1500kPa, this regulating valve shall be replaced.

• Pressure regulating valve that goes through burst test or durability test shall not be used on
the vehicle.
3.13.5 Fault phenomenon and judgment method

• Fault phenomenon: fuel pressure is too low or high, so it is difficult to start.

• General fault reason: lack of maintenance for a long time leads to: 1. filter screen clogged; 2.
particle impurity causes heavy leakage; 3. mechanical damage caused by human error etc.

• Maintenance notes: during the course of maintenance: 1. High pressure gas is forbidden to
impact diaphragm elements; 2. Strong corrosive liquid is forbidden to wash it; 3. No external
force is applied.

• Simple measuring method: connect fuel pressure gauge with fuel inlet pipe, start the engine
to run it idly, check if fuel pressure is about 350kPa; step on the accelerator until engine
speed reaches 2500rpm, and check if fuel pressure is about 350kPa.
3.14 Steel fuel distribution pipe assembly

Simple diagram

Fig. 3-54 Fuel distribution pipe assembly

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3.14.1 Installation position

On the intake manifold.

3.14.2 Working principle

Fuel distribution pipe assembly consists of fuel distribution pipe (KVS) and fuel injector (EV).
Used to store and distribute fuel.
3.14.3 Technical characteristic parameter

Limit data

Value
Amount Maxi- Unit
Minimum Typical
mum
Working temperature when fuel distribution pipes
-40 +120 °C
and O-ring are connected correctly
Maximum working temperature after immersion of
+130 °C
15 minutes
Maximum permissible vibration acceleration (peak) 300 m/s2

Refer to characteristic parameters of the pressure regulator for system pressure; refer to charac-
teristic parameters of the fuel injector for fuel requirements; the sealing requirement is that no fuel
leakage occurs at working pressure.

Inner diameter of fuel rubber hose is Φ7.9 ± 0.3.

3.14.4 Installation notes

• Fuel inlet pipe and rubber hose are tightened by clamps. The clamps shall match with rubber
hose to ensure fuel inlet pipe and rubber pipe are tightly connected.

• No cracks, scratches, groove, burrs and corrosion should be found in the inlet tube wall.

• Before assembling the fuel distribution pipe assembly, lubricate the O-ring under the lubrica-
tion injector using clean lubricant.
3.14.5 Fault phenomenon and judgment method

Sealing ability for fuel distribution pipe can be tested by pressure difference: test O ring of fuel
distribution pipe fuel injector; at 4.5bar, leakage limit value tested ≤ 1.5cm3/min.

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4. ME7 system checks diagnosis flow according to fault code.

Note:

1. Check the current steady-state fault that has been confirmed. Otherwise, diagnosis mistake
may occur.

2. A “multimeter” refers to a digital multimeter. A pointer multi-meter is forbidden to check EFI

system circuit.

3. Check a vehicle with anti-theft system. If it is required to replace ECU, please program ECU
after replacement.

4. If description of diagnostic trouble code is “too low circuit voltage”, it indicates that short cir-
cuit to ground might exist in this circuit; if description of diagnostic trouble code is “too high
circuit voltage”, it indicates that short circuit to power supply might exist in this circuit; if de-
scription of diagnostic trouble code is line failure, it indicates that open circuit might exist in
this circuit or many line faults exist.

Diagnosis help:
1. Fault code cannot be cleared and the fault is steady-state fault.

If it is an occasional fault, check if wire harness joint is loose.

2. No abnormality is found after checking according to steps above;

3. Do not ignore impact of vehicle maintenance conditions, cylinder pressure and mech-
anical ignition timing on the system during the inspection and repair.

4. Replace the ECU and conduct test.

If the trouble code can be cleared now, the fault position is in ECU; if the trouble code
is still not cleared, replace the original ECU and repeat the procedures and then con-
duct the inspection and test job again.

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5. ME7 system checks diagnosis flow according to fault phenomenon

Conduct preliminary inspection items at first before carrying out the fault diagnosis according to
engine fault symptoms:

1. Confirm that the engine fault indicator light works properly;

2. Conduct the inspection by the fault diagnostic instrument and confirm that no fault informa-
tion record is found;

3. Confirm that fault symptom described by the car owner in the complaint exists and confirm
conditions where the fault occurs.

And then check the appearance:

(1) Check if fuel pipe leaks;

(2) 2. Check that vacuum pipeline is broken, twisted and connected correctly;

(3) 3. Check that the intake pipeline is clogged, leaks, or crushed to become flat or damaged;

(4) 4. Check that high pressure line in the ignition system is broken, degraded and that the igni-
tion sequence is correct;

(5) Check if wire harness grounding is clean or fixed;

(6) 6. Check that various sensors and actuator connectors are loose or in poor contact.

Important note: If symptoms above exist, conduct maintenance and repair jobs corre-
sponding to the fault symptom. Otherwise subsequent fault diagnosis and repair jobs will
be impacted.

Diagnosis help:
1. Confirm the engine has no fault record;

2. Confirm that fault symptoms described by the car own in complaint do exist;

3. No abnormality is found after checking according to steps above;

4. Do not ignore impact of vehicle maintenance conditions, cylinder pressure, ignition

timing and fuel on the system during the inspection and repair.

5. Replace the ECU and conduct test.

If the fault symptom can be eliminated now, the fault position is in ECU; if the fault
symptom still exists, replace the original ECU and repeat the procedures and then
conduct the inspection and test job again.

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1. Engine does not turn, or runs slowly in starting.

2. Engine may rotate in dragging but fail to starting in starting.

3. Tough starting even when the car is warmed up.

4. Tough starting when the car is in cold state.

5. Starting is difficult at any time when the engine speed is normal.

6. Idling speed is not stable at any time when the starting is normal.

7. Starting is normal, but idling speed is not stable in warming up.

8. Starting is normal, but idling speed is not stable after warming up.

9. Starting is normal; idling speed is not stable or the engine stops with some load (such as,
turn on A/C).

10. Starting is normal, but idling speed is too high.

11. Engine speed fails to go up or engine stops in accelerating.

12. Response is slow in accelerating.

13. Force is weak and performance is poor in accelerating.

1. Engine does not turn, or runs slowly in starting.

General fault location: 1. Battery; 2. Start motor; 3. wire harness or start button; 4. Mechanical
parts of the engine.

General diagnosis process:

Test re-
S/N Operation steps: Next steps
sults
Use a multimeter to check voltage between two terminal Yes Next
1 posts of the battery. Check that voltage is approximately 8
~ -12V when the engine is starting. No Replace the battery

Yes Next
Press start button to start the engine and keep start button
2 pressed, check if positive electrode terminal post of start Repair or replace
motor has the voltage of 8V above. No
the harness.

Dismantle the starter electric motor, and check working Repair or replace the
conditions of the starter electric motor. Focus on checking Yes
3 starter electric motor
that open circuit exists or seizure occurs due to poor lubri-
cation. No Next

If the fault occurs only in winter, check that the reason why Use lubricants with
the starter electric motor resistance is too large is because Yes proper grade and
4 brand.
of the improper selection of engine lubricating oil and gear-
box oil. No Next

Check internal resis-

Check that mechanical resistance in the engine is too Yes
tance of the engine
5 large and that it cause a failure of the electric motor rota-
tion or slow rotation. Instructions for diag-
No
nosis

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2. Engine may rotate in dragging but fail to starting in starting.

General fault location: 1. fuel tank is empty; 2. fuel pump; 3. speed sensor; 4. ignition coil; 5. Me-
chanical parts of the engine.

General diagnosis process:

Test
S/N Operation steps: Next steps
results

Connect the fuel pressure gauge (connection point is the in- Yes Next
let pipe front end of the fuel distribution pipe assembly). Start
1
the engine and check that the fuel pressure is approximately Check and inspect
350kPa. No
the fuel system
Connect up the diagnostic instrument of electronic fuel injec- Next
tion system. Observe “engine speed” item among data stream
2 Check speed sen-
and start the engine. Observe whether the rotating speed sig- No
nal is outputted.Yes sor circuit

Pull out the ignition coil of one cylinder and connect up the Yes Next
spark plug. Keep spark plug electrode 5mm away from the
3
engine body. Start the engine and check that blue and white
Check and inspect
high-pressure fire exists. No
the ignition system
Eliminate the en-
Check pressure of reach engine cylinder; observe whether the Yes gine mechanical
4 fault
engine cylinder is in the lack of pressure or not.
No Next

3. Tough starting even when the car is warmed up.

General faulty parts: 1. Fuel containing water; 2. Fuel pump; 3. Coolant temperature sensor; 4.
Fuel pressure regulator vacuum tube;5. Ignition coil.

General diagnosis process:

Test
S/N Operation steps: Next steps
results
Connect the fuel pressure gauge (connection point is the in- Yes Next
let pipe front end of the fuel distribution pipe assembly). Start
1 Check and inspect
the engine and check that the fuel pressure is approximately No
350kPa. the fuel system

Pull out the ignition coil of one cylinder and connect up the Yes Next
spark plug. Keep spark plug electrode 5mm away from the en-
2 Check and inspect
gine body. Start the engine and check that blue and white high- No
pressure fire exists. the ignition system

Remove the coolant temperature sensor connector, start the Check circuit or
Yes
engine, and observe whether the engine can be success- replace the sensor
fully started or not. (Or Connect one 300 ohms resistor in the
3
coolant temperature sensor connector to replace the coolant
temperature sensor. Now observe whether the engine can be No Next
successfully started or not.)
Yes Repair or replace it
4 Check if fuel pressure regulator vacuum pipe is loose or leaks.
No Next
Check fuel conditions. Observe that fault symptom is resulted Yes Replace fuel
5
from due to fuel added just a moment ago. No Next

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4. Tough starting when the car is in cold state.

General fault location: 1. Fuel containing water; 2. Fuel pump; 3. Coolant temperature sensor; 4.
Fuel injector; 5. Ignition coil; 6. Throttle body; 7. Mechanical parts of the engine.

General diagnosis process:

Test
S/N Operation steps: Next steps
results
Connect the fuel pressure gauge (connection point is the in- Yes Next
let pipe front end of the fuel distribution pipe assembly). Start
1 Check and inspect
the engine and check that the fuel pressure is approximately No
350kPa. the fuel system

Pull out the ignition coil of one cylinder and connect up the Yes Next
spark plug. Keep spark plug electrode 5mm away from the en-
2 Check and inspect
gine body. Start the engine and check that blue and white high- No
pressure fire exists. the ignition system

Remove the coolant temperature sensor connector, start the Check circuit or re-
Yes
engine, and observe whether the engine can be successfully place the sensor
started or not. (Or Connect one 2500 ohms resistor in the
3
coolant temperature sensor connector to replace the coolant
temperature sensor. Now observe whether the engine can be No Next
successfully started or not.)
Clean the throttle
Gently depress the accelerator, and observe whether it can be Yes
4 and idling airway
easily started.
No Next
Remove the fuel injector. Use the special cleaning analyzer for Yes Replacement of fault
5
fuel injector to check the fuel injector for leakage or clogging. No Next
Check fuel conditions. Observe that fault symptom is resulted Yes Replace fuel
6
from due to fuel added just a moment ago. No Next
Eliminate the engine
Check pressure of reach engine cylinder; observe whether the Yes
7 mechanical fault
engine cylinder is in the lack of pressure or not.
No Next
Instructions for diag-
Yes
Connect EFI system adapter, start the engine, check if power nosis
8 supply for pins12#, 13#, 44#, 45# and 63# is normal; check if Check and repair
grounding for pins 3#, 51#, 53#, 61# and 80# are normal. No corresponding cir-
cuits

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5. Starting is difficult at any time when the engine speed is normal.

General fault location: 1. Fuel containing water; 2. fuel pump; 3. Coolant temperature sensor; 4.
Fuel injector; 5. Ignition coil;6. Electronic throttle body; 7.Air inlet; 8.Ignition timing; 9.Spark plug;
10.Mechanical parts of the engine.

General diagnosis process:

Test
S/N Operation steps: Next steps
results
Check and inspect
Check that the air filter is clogged, and the air intake channel Yes
1 the intake system
has air leakage.
No Next

Connect the fuel pressure gauge (connection point is the inlet Yes Next
pipe front end of the fuel distribution pipe assembly). Start
2
the engine and check that the fuel pressure is approximately Check and inspect
350kPa. No
the fuel system

Pull out the ignition coil of one cylinder and connect up the Yes Next
spark plug. Keep spark plug electrode 5mm away from the
3
engine body. Start the engine and check that blue and white
Check and inspect
high-pressure fire exists. No
the ignition system

Check spark plug for each cylinder. Observe that model and Yes Next
4
clearance are consistent with specifications. No Adjust or replace it

Remove the coolant temperature sensor connector, start the Check circuit or re-
Yes
5 engine, and observe whether the engine can be successfully place the sensor
started or not.
No Next
Clean the throttle
Gently depress the accelerator, and observe whether it can Yes
6 and idling airway
be easily started.
No Next
Remove the fuel injector. Use the special cleaning analyzer Replacement of
Yes
7 for fuel injector to check the fuel injector for leakage or clog- fault
ging. No Next
Check fuel conditions. Observe that fault symptom is resulted Yes Replace fuel
8
from due to fuel added just a moment ago. No Next
Eliminate the en-
Check pressure of reach engine cylinder; observe whether Yes gine mechanical
9 fault
the engine cylinder is in the lack of pressure or not.
No Next
Yes Next
10 Check that engine firing order and ignition timing is correct. Check ignition tim-
No
ing

Instructions for di-

Yes
Connect EFI system adapter, start the engine, check if power agnosis
11 supply for pins12#, 13#, 44#, 45# and 63# is normal; check if
Check and repair
grounding for pins 3#, 51#, 53#, 61# and 80# are normal.
No corresponding cir-
cuits

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6. Idling speed is not stable at any time when the starting is normal.

General fault location: 1. Fuel containing water; 2. Fuel injector; 3. Spark plug; 4. Throttle body
and idle speed bypass air duct; 5. Air inlet; 6. Electronic throttle body; 7. Ignition timing;8. Spark
plug; 9.Mechanical parts of the engine.

General diagnosis process:

Test re-
S/N Operation steps: Next steps
sults
Check and in-
Check that the air filter is clogged, and the air intake channel Yes spect the intake
1 system
has air leakage.
No Next
Clean or replace
Yes
2 Check if idle speed regulator is not smooth. it
No Next
Yes Next
Check spark plug for each cylinder. Observe that model and
3 Adjust or replace
clearance are consistent with specifications. No
it
Check the throttle body and idling speed bypass air channel Yes Clean it
4
for coke formation. No Next
Remove the fuel injector. Use the special cleaning analyzer for Replacement of
Yes
5 fuel injector to check the fuel injector for leakage, or clogging fault
or flowrate out-of-tolerance. No Next
Check fuel conditions. Observe that fault symptom is resulted Yes Replace fuel
6
from due to fuel added just a moment ago. No Next
Eliminate the en-
Check pressure of reach engine cylinder; observe whether the Yes gine mechanical
7 fault
engine cylinder pressure is in big difference or not.
No Next
Yes Next
8 Check that engine firing order and ignition timing is correct. Check ignition
No
timing

Instructions for
Yes
Connect EFI system adapter, start the engine, check if power diagnosis
9 supply for pins12#, 13#, 44#, 45# and 63# is normal; check if
Check and repair
grounding for pins 3#, 51#, 53#, 61# and 80# are normal.
No corresponding
circuits

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7. Starting is normal, but idling speed is not stable in warming up.

General fault location: 1. Fuel containing water; 2. Coolant temperature sensor; 3. Spark plug; 4.
Throttle body carbon deposition; 5. Air inlet; 6. Mechanical parts of the engine.

General diagnosis process:

Test
S/N Operation steps: Next steps
results
Check and inspect
Check that the air filter is clogged, and the air intake channel Yes
1 the intake system
has air leakage.
No Next
Check spark plug for each cylinder. Observe that model and Yes Next
2
clearance are consistent with specifications. No Adjust or replace it
Clean related
Yes
3 Check if throttle body has carbon deposition. parts
No Next
Remove the coolant temperature sensor connector, start the Check circuit or
Yes
4 engine, and observe whether the engine can run unstably in replace the sensor
warm-up process. No Next
Remove the fuel injector. Use the special cleaning analyzer for Replacement of
Yes
5 fuel injector to check the fuel injector for leakage, or clogging fault
or flowrate out-of-tolerance. No Next
Check fuel conditions. Observe that fault symptom is resulted Yes Replace fuel
6
from due to fuel added just a moment ago. No Next
Eliminate the en-
Check pressure of reach engine cylinder; observe whether the Yes gine mechanical
7 fault
engine cylinder pressure is in big difference or not.
No Next
Instructions for di-
Yes
Connect EFI system adapter, start the engine, check if power agnosis
8 supply for pins12#, 13#, 44#, 45# and 63# is normal; check if Check and repair
grounding for pins 3#, 51#, 53#, 61# and 80# are normal. No corresponding cir-
cuits

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8. Starting is normal, but idling speed is not stable after warming up.

General fault location: 1. Fuel containing water; 2. coolant temperature sensor; 3. Spark plug; 4.
Electronic throttle body; 5. Air inlet; 6. Mechanical parts of the engine.

General diagnosis process:

Test
S/N Operation steps: Next steps
results
Check and inspect
Check that the air filter is clogged, and the air intake channel Yes
1 the intake system
has air leakage.
No Next
Check spark plug for each cylinder. Observe that model and Yes Next
2
clearance are consistent with specifications. No Adjust or replace it
Yes Clean related parts
3 Check if throttle body has carbon deposition.
No Next
Remove the coolant temperature sensor connector, start the Check circuit or re-
Yes
4 engine, and observe whether the engine can run unstably in place the sensor
warm-up process. No Next
Remove the fuel injector. Use the special cleaning analyzer for Replacement of
Yes
5 fuel injector to check the fuel injector for leakage, or clogging fault
or flowrate out-of-tolerance. No Next
Check fuel conditions. Observe that fault symptom is resulted Yes Replace fuel
6
from due to fuel added just a moment ago. No Next
Eliminate the en-
Check pressure of reach engine cylinder; observe whether the Yes gine mechanical
7 fault
engine cylinder pressure is in big difference or not.
No Next

Instructions for di-

Yes
Connect EFI system adapter, start the engine, check if power agnosis
8 supply for pins12#, 13#, 44#, 45# and 63# is normal; check if
Check and repair
grounding for pins 3#, 51#, 53#, 61# and 80# are normal.
No corresponding cir-
cuits

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9. Starting is normal; idling speed is not stable or the engine stops with some load (such as,
turn on A/C).

General fault location: 1. Air conditioner system; 2. Idle speed regulator; 3. Fuel injector

General diagnosis process:

Test re-
S/N Operation steps: Next steps
sults
Clean related
Yes
1 Check if throttle body has carbon deposition. parts
No Next

Observe whether the engine output power increases with A/C Yes To step 4
on or not; use the EFI system diagnostic instrument to observe
2
change of ignition advance angle, fuel injection pulse width
and air input. No Next

Yes Next
Connect up the EFI system and disconnect connection line of
3 the electronic control unit 75 # pin. Check that with A/C on, wir- Check and in-
ing harness end has high level signal. No spect the A/C
system
Yes Next
Check that A/C system pressure, compressor electromagnetic Check and in-
4
clutch and A/C compressor pump are in normal condition. No spect the A/C
system
Remove the fuel injector. Use the special cleaning analyzer for Replacement of
Yes
5 fuel injector to check the fuel injector for leakage, or clogging fault
or flowrate out-of-tolerance. No Next

Instructions for
Yes
Connect EFI system adapter, start the engine, check if power diagnosis
6 supply for pins12#, 13#, 44#, 45# and 63# is normal; check if
Check and repair
grounding for pins 3#, 51#, 53#, 61# and 80# are normal.
No corresponding
circuits

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10. Starting is normal, but idling speed is too high.

General fault location: 1. Throttle body and idle speed bypass air duct; 2. Vacuum pipe; 3. Idle
speed regulator; 4. coolant temperature sensor; 5. ignition timing.

General diagnosis process:

Test
S/N Operation steps: Next steps
results
Yes Adjust it
1 Check that accelerator cable is stuck or too tight.
No Next
Check and inspect
Check that the intake system or the connected vacuum pipe- Yes
2 the intake system
line has air leakage.
No Next
Dismantle idle speed regulator, check if throttle body, idle Yes Clean related parts
3 speed regulator and idling bypass air duct have carbon depo-
sition. No Next

Check circuit or re-

Pull out coolant temperature sensor joint, start the engine and Yes
4 place the sensor
check if idle speed of the engine is too high.
No Next
Yes Next
5 Check that engine ignition timing is correct. Check ignition tim-
No
ing

Instructions for di-

Yes
Connect EFI system adapter, start the engine, check if power agnosis
6 supply for pins12#, 13#, 44#, 45# and 63# is normal; check if
Check and repair
grounding for pins 3#, 51#, 53#, 61# and 80# are normal.
No corresponding cir-
cuits

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11. Engine speed fails to go up or engine stops in accelerating.

General faulty parts: 1. Fuel containing water; 2. Intake combustion analyzer or throttle position
sensor 3. Spark plug; 4. Throttle body and idling speed bypass air channel; 5. Air intake channel;
6.Idle stepper motor; 7.Fuel injector; 8.Ignition timing; 9.Exhaust pipe.

General diagnosis process:

Test re-
S/N Operation steps: Next steps
sults
Check and
Yes inspect the
1 Check that the air filter is clogged intake system
No Next

Connect the fuel pressure gauge (connection point is the inlet Yes Next
pipe front end of the fuel distribution pipe assembly) . Start
2 Check and
the engine and check that the fuel pressure is approximately
350kPa during acceleration. No inspect the fuel
system
Yes Next
Check spark plug for each cylinder. Observe that model and
3 Adjust or re-
clearance are consistent with specifications. No
place it
Dismantle idle speed regulator, check if throttle body, idle Clean related
Yes
4 speed regulator and idling bypass air duct have carbon deposi- parts
tion. No Next
Yes Next
Check that the intake air pressure sensor, the throttle position Check circuit
5
sensor and their circuit are in normal condition. No or replace the
sensor
Replacement
Remove the fuel injector. Use the special cleaning analyzer for Yes
6 of fault
fuel injector to check the fuel injector for leakage or clogging.
No Next
Check fuel conditions. Observe that fault symptom is resulted Yes Replace fuel
7
from due to fuel added just a moment ago. No Next
Yes Next
8 Check that engine firing order and ignition timing is correct. Check ignition
No
timing
Yes Next

9 Check that air in exhaust pipe can flow smoothly. Repair or

No replace the
exhaust pipe

Instructions for
Yes
diagnosis
Connect EFI system adapter, start the engine, check if power
10 supply for pins12#, 13#, 44#, 45# and 63# is normal; check if Check and
grounding for pins 3#, 51#, 53#, 61# and 80# are normal. repair cor-
No
responding
circuits

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12. Response is slow in accelerating.

General faulty parts: 1. Fuel containing water; 2. Intake combustion analyzer or throttle position
sensor 3. Spark plug; 4. Throttle body and idling speed bypass air channel; 5. Air intake channel;
6.Idle stepper motor; 7.Fuel injector; 8.Ignition timing; 9.Exhaust pipe.

General diagnosis process:

Test
S/N Operation steps: Next steps
results
Check and inspect
Yes
1 Check that the air filter is clogged the intake system
No Next

Connect the fuel pressure gauge (connection point is the inlet Yes Next
pipe front end of the fuel distribution pipe assembly) . Start
2
the engine and check that the fuel pressure is approximately Check and inspect
350kPa during acceleration. No
the fuel system

Check spark plug for each cylinder. Observe that model and Yes Next
3
clearance are consistent with specifications. No Adjust or replace it
Dismantle idle speed regulator, check if throttle body, idle Clean related
Yes
4 speed regulator and idling bypass air duct have carbon deposi- parts
tion. No Next
Yes Next
Check that the intake air pressure sensor, the throttle position
5 Check circuit or
sensor and their circuit are in normal condition. No
replace the sensor

Replacement of
Remove the fuel injector. Use the special cleaning analyzer for Yes
6 fault
fuel injector to check the fuel injector for leakage or clogging.
No Next
Check fuel conditions. Observe that fault symptom is resulted Yes Replace fuel
7
from due to fuel added just a moment ago. No Next
Yes Next
8 Check that engine firing order and ignition timing is correct. Check ignition tim-
No
ing
Yes Next
9 Check that air in exhaust pipe can flow smoothly. Repair or replace
No
the exhaust pipe

Instructions for
Yes
Connect EFI system adapter, start the engine, check if power diagnosis
10 supply for pins12#, 13#, 44#, 45# and 63# is normal; check if
Check and repair
grounding for pins 3#, 51#, 53#, 61# and 80# are normal.
No corresponding
circuits

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 BYD S6, S6A, S6K Service Manual

13. Force is weak and performance is poor in accelerating.

General fault location: 1. Fuel containing water; 2. intake pressure sensor; 3. Spark plug; 4. Igni-
tion coil; 5. Throttle body; 6. Air inlet; 7. Fuel injector; 8. Ignition timing; 19. Exhaust pipe.

General diagnosis process:

Test re-
S/N Operation steps: Next steps
sults
Check that the clutch is slipping, the tire pressure is low, the Yes Repair
1 brake operation is dragging, the tire size is wrong and the
wheel alignment is conducted in a wrong manner. No Next

Check and in-

Yes spect the intake
2 Check that the air filter is clogged system
No Next

Connect the fuel pressure gauge (connection point is the inlet Yes Next
pipe front end of the fuel distribution pipe assembly) . Start
3 Check and
the engine and check that the fuel pressure is approximately
350kPa during acceleration. No inspect the fuel
system

Pull out the ignition coil of one cylinder and connect up the Yes Next
spark plug. Keep spark plug electrode 5mm away from the
4
engine body. Start the engine and check that high pressure fire Check and
strength is normal. No inspect the igni-
tion system
Yes Next
Check spark plug for each cylinder. Observe that model and
5 Adjust or re-
clearance are consistent with specifications. No
place it
Clean related
Yes
6 Check if carbon deposits on throttle body and air inlet. parts
No Next
Yes Next

7 Check if intake pressure sensor and throttle wire are normal. Check circuit or
No replace the sen-
sor
Replacement of
Remove the fuel injector. Use the special cleaning analyzer for Yes
8 fault
fuel injector to check the fuel injector for leakage or clogging.
No Next
Check fuel conditions. Observe that fault symptom is resulted Yes Replace fuel
9
from due to fuel added just a moment ago. No Next
Yes Next
10 Check that engine firing order and ignition timing is correct. Check ignition
No
timing
Yes Next

11 Check that air in exhaust pipe can flow smoothly. Repair or re-
No place the ex-
haust pipe

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6. ME7system diagnosis tester function requirement

Diagnosis tester shall be provided with the following functions:

I. Self-diagnosis

Mainly include: read fault code and clear fault code;

II. System parameter display

Mainly include: Water temperature, intake temperature, throttle opening, engine speed, ignition
angle, short-time correction of air-fuel ratio, long-time addition and multiplication correction of air-
fuel ratio, intake pressure, intake flow rate, oxygen sensor signal, system voltage and torque de-
mand value;

III. System state

Mainly include: display programming state, cooling system, stable working conditions, dynamic
working conditions, emission control, oxygen sensor, idle speed, MIL, emergent operation and air
conditioner;

IV. Actuator testing

Mainly include: MIL, fuel pump, A/C relay, fan control, ignition test, single cylinder fuel cut-off;

V. System initialization reset (self-adaption value reset)

After the engine flames out, initialization command is sent. The system will reset the previous self-
adaption.

VI. Speedometer

Mainly include: travel distance and travel time;

VII. Version information

Mainly include: vehicle identification code (optional), ECU hardware number, ECU software num-
ber.

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7. Accessories:
7.1 Installation force of parts/ torque specification table

S/N Part name Installation torque (NM)

1 Intake pressure temperature sensor 3.3
2 Coolant Temp Sensor 20(Max)
3 Knock sensor 20 ± 5
4 Oxygen sensor 50 ± 10
5 Throttle position sensor 2 ± 0.5
6 Speed sensor 8±2
7 Phase sensor 8 ± 0.5
8 Electromagnetic fuel injector 6

7.2 Maintenance regulations for EFI system

7.2.1 Family Cars

Explanation:

1. The maintenance procedures are applicable to family cars;

2. Maintenance interval; reading in odometer or time interval, whichever comes first;

3. Maintenance procedures are prepared based on the normal use, and must be strictly ob-
served.

Mileage
10 20 30 40 50 60 70 80
x1000km
Items
Months
3 6 9 12 15 18 21 24
Month
Ignition Coil I I I I
Ignition Cam I I I I
Ignition Cap I I I I
Ignition Wire I I I I
Spark Plug I I I R
Ignition Timing I I I I
Engine Idling Speed I I I I
Fuel Tank I C
Fuel Filter R R R R
Fuel Injector C C C C
Air Filter I R I R
EWD or Stepper Air Bypass C C C C
Throttle Body C C C C
Emission Check I I I I
Check by Diagnostic Tool I I I I

7.2.2 Taxi

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 BYD S6, S6A, S6K Service Manual

Explanation:

1. The maintenance procedures are applicable to taxi;

2. Maintenance interval; reading in odometer or time interval, whichever comes first;

3. Maintenance procedures are prepared based on the normal use, and must be strictly ob-
served.

Mileage
20 40 60 80 100 120 140 160
x1000km
Items
Months
3 6 9 12 15 18 21 24
Month
Ignition Coil I I I I I I I I
Ignition Cam I I I I I I I I
Ignition Cap I I I I I I I I
Ignition Wire I I I I I I I I
Spark Plug I R I R
Ignition Timing I I I I
Engine Idling Speed I I I I
Fuel Tank C C
Fuel Filter R R R R R R R R
Fuel Injector C C C C C C C C
Air Filter I R I R I R I R
EWD or Stepper Air Bypass I C I C I C I C
Throttle Body I C I C I C I C
Emission Check I I I I
Check by Diagnostic Tool I I I I

Note: R-Replace

C-Clean

I -Inspect (Replace the spare parts when find out failure in inspection.)

C*-The maintenance of fuel injector had better clean by a special tool --- fuel injector
cleaner.

7.3 Fault code (PCODE) list

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 BYD S6, S6A, S6K Service Manual

S/N Trouble code Fault code description

1 P000A Intake air VVT running is unreasonable
2 P0010 Intake air VVT circuit is open
3 P0012 Intake air VVT locking position is unreasonable
4 P0016 Relative position of crankshaft and cam shaft are faulty
5 P0030 Upstream oxygen sensor heating control circuit is open
6 P0031 Upstream oxygen sensor heating control circuit is short to the ground
7 P0032 Upstream oxygen sensor heating control circuit is short to the battery
8 P0036 Downstream oxygen sensor heating control circuit is open
9 P0037 Downstream oxygen sensor heating control circuit is short to the ground
10 P0038 Downstream oxygen sensor heating control circuit is short to power supply
11 P0053 Upstream oxygen sensor heating internal resistance is unreasonable
12 P0054 Downstream oxygen sensor heating internal resistance is unreasonable
13 P0105 Intake pressure sensor signal is unchanged (frozen)
14 P0106 Intake pressure sensor is unreasonable
15 P0107 Intake pressure sensor is short to the ground
16 P0108 Intake pressure sensor is short to the battery
17 P0112 Intake temperature sensor signal voltage is too low
18 P0113 Intake temperature sensor signal voltage is too high
19 P0116 Engine coolant temperature sensor is unreasonable
20 P0117 Engine coolant temperature sensor circuit voltage is too low
21 P0118 Engine coolant temperature sensor circuit voltage is too high
22 P0121 Throttle valve position sensor 1 signal is unreasonable
23 P0122 Throttle valve position sensor 1 signal circuit voltage is too low
24 P0123 Throttle valve position sensor 1 signal circuit voltage is too high
25 P0130 Upstream oxygen sensor signal is unreasonable
26 P0131 Upstream oxygen sensor signal circuit voltage is too low
27 P0132 Upstream oxygen sensor signal circuit voltage is too high
28 P0133 Upstream oxygen sensor is aging
29 P0134 Upstream oxygen sensor circuit signal fault
30 P0136 Downstream oxygen sensor signal is unreasonable
31 P0137 Downstream oxygen sensor signal voltage is too low
32 P0138 Downstream oxygen sensor signal circuit voltage is too high
33 P0140 Downstream oxygen sensor circuit signal fault
34 P0170 Off-line detection for air-fuel ratio closed-loop control self-learning is unreasonable
35 P0171 Off-line detection for air-fuel ratio closed-loop control self-learning is too thin
36 P0172 Off-line detection for air-fuel ratio closed-loop control self-learning is too strong
37 P0201 Cylinder #1 fuel injector control circuit is open
38 P0202 Cylinder #2 fuel injector control circuit is open

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39 P0203 Cylinder #3 fuel injector control circuit is open

40 P0204 Cylinder #4 fuel injector control circuit is open
41 P0219 Engine speed exceeds the maximum speed limit
42 P0221 Throttle valve position sensor 2 signal is unreasonable
43 P0222 Throttle valve position sensor 2 signal circuit voltage is too low
44 P0223 Throttle valve position sensor 2 signal circuit voltage is too high
45 P0261 Cylinder #1 fuel injector control circuit is short to the ground
46 P0262 Cylinder #1 fuel injector control circuit is short to the battery
47 P0264 Cylinder #2 fuel injector control circuit is short to the ground
48 P0265 Cylinder #2 fuel injector control circuit is short to the battery
49 P0267 Cylinder #3 fuel injector control circuit is short to the ground
50 P0268 Cylinder #3 fuel injector control circuit is short to the battery
51 P0270 Cylinder #4 fuel injector control circuit is short to the ground
52 P0271 Cylinder #4 fuel injector control circuit is short to the battery
53 P0300 Multi-cylinder misfire
54 P0301 Cylinder #1 misfire
55 P0302 Cylinder #2 misfire
56 P0303 Cylinder #3 misfire
57 P0304 Cylinder #4 misfire
58 P0321 DG-to-speed signal gear teeth missing BM signal is lost frequently
59 P0322 Without speed sensor pulse signal (open circuit or short circuit)
60 P0327 Knock sensor signal circuit voltage is too low
61 P0328 Knock sensor signal circuit voltage is too high
62 P0340 Phase sensor installation position is improper
63 P0341 Phase sensor contact is poor
64 P0342 Phase sensor is short to the ground
65 P0343 Phase sensor is short to the battery
Three-way catalytic converter oxygen storage capacity is aging (emission exceeds
66 P0420
the limit)
67 P0444 Canister control valve control circuit is open
68 P0458 Canister control valve control circuit voltage is too low
69 P0459 Canister control valve control circuit voltage is too high
70 P0480 Cooling fan relay control circuit is open (low speed)
71 P0481 Cooling fan relay control circuit is open (high speed)
72 P0501 Vehicle speed sensor signal is unreasonable
73 P0506 Idle speed control is lower than target idle speed
74 P0507 Idle speed control is higher than target idle speed
75 P0537 A/C temperature sensor is short to the ground
76 P0538 A/C temperature sensor is short to the battery

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77 P0560 The system battery voltage signal is unreasonable

78 P0562 The system battery voltage is too low
79 P0563 The system battery voltage is too high
Brake switch signal circuit fault or brake lamp switch correlation is not synchro-
80 P0571
nous
81 P0602 Electronic control unit code fault
82 P0604 Electronic control unit RAM fault
83 P0605 Electronic control unit ROM fault
84 P0606 Electronic throttle valve safety monitoring function fault
85 P0627 Fuel pump relay control circuit is open
86 P0628 Fuel pump relay control circuit is short to the ground
87 P0629 Fuel pump relay control circuit is short to the battery
88 P0645 A/C compressor relay control circuit is open
89 P0646 A/C compressor relay control circuit is short to the ground
90 P0647 A/C compressor relay control circuit is short to the battery
91 P0650 MIL driving stage circuit
92 P0688 Main relay output voltage is unreasonable
93 P0691 Cooling fan relay control circuit is short to the ground (low speed)
94 P0692 Cooling fan relay control circuit is short to the battery (low speed)
95 P0693 Cooling fan relay control circuit is short to the ground (high speed)
96 P0694 Cooling fan relay control circuit is short to the battery (high speed)
97 P0704 Clutch pedal switch signal is incorrect.
98 P1336 Electronic throttle valve safety monitoring torque restriction
The deviation between actual position and target position of electronic throttle
99 P1545
valve exceeds the limit
100 P1558 Opening resistance of electronic throttle valve is too high
101 P1559 Electronic throttle valve self-learning process fault
The system voltage does not satisfy electronic throttle valve self-learning condi-
102 P1564
tions
103 P1565 Electronic throttle valve lower limit position initialization self-learning fault
104 P1568 Electronic throttle valve return resistance is too high
105 P1579 Electronic throttle valve self-learning condition is not satisfied
106 P1604 Electronic throttle valve gain adjustment self-learning fault
107 P1610 Anti-theft key has no code
108 P1611 Anti-theft code of the key is wrong
109 P1612 Communication between anti-theft device and ECU is off
110 P1613 Communication between anti-theft device and ECU is off
111 P1614 Anti-theft key chip fault
112 P1651 SVS lamp driving stage circuit fault
113 P2088 Intake VVT is short to the ground

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114 P2089 Intake VVT is short to the battery

115 P2106 Electronic throttle valve driving stage fault
116 P2122 Electronic accelerator pedal position sensor 1 signal voltage is too low
117 P2123 Electronic accelerator pedal position sensor 1 signal voltage is too high
118 P2127 Electronic accelerator pedal position sensor 2 signal voltage is too low
119 P2128 Electronic accelerator pedal position sensor 2 signal voltage is too high
120 P2138 Electronic accelerator pedal position sensor signal is unreasonable
Air-fuel ratio closed-loop control self-learning value exceeds upper limit (medium
121 P2177
loading zone)
Air-fuel ratio closed-loop control self-learning value exceeds lower limit (medium
122 P2178
loading zone)
Air-fuel ratio closed-loop control self-learning value exceeds upper limit (low load-
123 P2187
ing zone)
Air-fuel ratio closed-loop control self-learning value exceeds lower limit (low load-
124 P2188
ing zone)
125 P2195 Upstream oxygen sensor is aging
126 P2196 Upstream oxygen sensor is aging
127 P2270 Downstream oxygen sensor is aging
128 P2271 Downstream oxygen sensor is aging

7.4 Wire harness diagram

(Please review detailed drawings of the project)

Please follow Operation Manual strictly to find out faults and make maintenance.

503