ENGINE CONTROL

SECTION EC
CONTENTS
PRECAUTIONS .................................................. EC-3 CAMSHAFT POSITION SENSOR (PHASE)
General precautions for service operations .... EC-3 SYSTEM ............................................................ EC-56
PREPARATION .................................................. EC-4 ECM Input/Output Signal Specifications ...... EC-56
Special Service Tools ..................................... EC-4 Circuit Diagram ............................................. EC-56
DESCRIPTION .................................................... EC-5 Component Parts Inspection ........................ EC-56
BASIC INSPECTION ........................................ EC-11 MASS AIR FLOW SENSOR SYSTEM ............. EC-57
Inspection of Idle Speed, Ignition Timing, Service tool Data Monitor Display ................ EC-57
and Air-fuel Ratio .......................................... EC-11 ECM Input/Output Signal Specifications ...... EC-57
Throttle Valve Closed Position Learning and Circuit Diagram ............................................. EC-57
Idle Air Volume Learning .............................. EC-13 Component Parts Inspection ........................ EC-57
Accelerator Pedal Released Position ENGINE COOLANT TEMPERATURE SENSOR
Learning ....................................................... EC-14 SYSTEM ............................................................ EC-58
Fuel pressure inspection .............................. EC-14 Service tool Data Monitor Display ................ EC-58
TROUBLE DIAGNOSIS .................................... EC-16 ECM Input/Output Signal Specifications ...... EC-58
How to Proceed with Trouble Diagnosis ...... EC-16 Circuit Diagram ............................................. EC-58
Diagnosis Chart by Symptom ....................... EC-20 Component Parts Inspection ........................ EC-58
Component Parts Location ........................... EC-26 HEATED OXYGEN SENSOR SYSTEM ........... EC-59
ECM Component .......................................... EC-27 Service tool Data Monitor Display ................ EC-59
Circuit Diagram ............................................. EC-30 ECM Input/Output Signal Specifications ...... EC-59
ECM Terminal Layout ................................... EC-33 Circuit Diagram ............................................. EC-59
ECM Input/Output Signal Specifications ...... EC-36 THROTTLE POSITION SENSOR SYSTEM ..... EC-60
Service tool ................................................... EC-42 Service tool Data Monitor Display ................ EC-60
Self-Diagnosis Function ECM Input/Output Signal Specifications ...... EC-60
(Without Service tool) ................................... EC-47 Circuit Diagram ............................................. EC-60
Service tool Reference Value in Component Parts Inspection ........................ EC-60
Data Monitor ................................................. EC-50 ACCELERATOR PEDAL POSITION SENSOR
Fail-Safe Function ........................................ EC-53 SYSTEM ............................................................ EC-61
POWER SUPPLY AND GROUND SYSTEM .... EC-54 Service tool Data Monitor Display ................ EC-61
ECM Input/Output Signal Specifications ...... EC-54 ECM Input/Output Signal Specifications ...... EC-61
Circuit Diagram ............................................. EC-54 Circuit Diagram ............................................. EC-61
CRANKSHAFT POSITION SENSOR (POS) Component Parts Inspection ........................ EC-61
SYSTEM ............................................................ EC-55 INTAKE AIR TEMPERATURE SENSOR ......... EC-62
ECM Input/Output Signal Specifications ...... EC-55 Service tool Data Monitor Display ................ EC-62
Circuit Diagram ............................................. EC-55 ECM Input/Output Signal Specifications ...... EC-62
Component Parts Inspection ........................ EC-55 Circuit Diagram ............................................. EC-62
Component Parts Inspection ........................ EC-62
PNP SWITCH SYSTEM .................................... EC-63 System Diagram .......................................... EC-73
Service tool Data Monitor Display ................ EC-63 Component Parts Inspection ........................ EC-73
ECM Input/Output Signal Specifications ...... EC-63 FUEL CUT FUNCTION ..................................... EC-74
Circuit Diagram ............................................ EC-63 Inspection Procedure ................................... EC-74
STOP LAMP SWITCH SYSTEM ...................... EC-64 REMOVAL AND INSTALLATION OF ECM
Service tool Data Monitor Display ................ EC-64 COMPONENTS ................................................ EC-75
ECM Input/Output Signal Specifications ...... EC-64 Removal and Installation of ECM ................. EC-75
Circuit Diagram ............................................ EC-64 Removal and Installation of Crankshaft
Component Parts Inspection ........................ EC-64 Position Sensor (POS) ................................. EC-75
ELECTRIC LOAD SWITCH SYSTEM .............. EC-65 Removal and Installation of Camshaft
Service tool Data Monitor Display ................ EC-65 Position Sensor (PHASE) ............................ EC-75
ECM Input/Output Signal Specifications ...... EC-65 Removal and Installation of Mass Air Flow
Circuit Diagram ............................................ EC-65 Sensor .......................................................... EC-76
CAN COMMUNICATION SYSTEM .................. EC-66 Removal and Installation of Engine Coolant
ECM Input/Output Signal Specifications ...... EC-66 Temperature Sensor. ................................... EC-76
Circuit Diagram ............................................ EC-66 Removal and Installation of Heated Oxygen
IGNITION SYSTEM ........................................... EC-67 Sensor (with Heated Oxygen Sensor
Service tool Data Monitor Display ................ EC-67 Heater) ......................................................... EC-76
ECM Input/Output Signal Specifications ...... EC-67 Removal and Installation of Throttle Position
Circuit Diagram ............................................ EC-67 Sensor (Electric Throttle Control Actuator
Component Parts Inspection ........................ EC-67 Assembly) .................................................... EC-77
FUEL INJECTOR SYSTEM .............................. EC-69 Removal and Installation of Accelerator
Service tool Data Monitor Display ................ EC-69 Pedal Position Sensor (Accelerator Pedal
ECM Input/Output Signal Specifications ...... EC-69 Assembly) .................................................... EC-77
Circuit Diagram ............................................ EC-69 Removal and Installation of Intake Air
Component Parts Inspection ........................ EC-69 Temperature Sensor (with Mass Air Flow
FUEL PUMP SYSTEM ...................................... EC-70 Sensor) ........................................................ EC-77
Service tool Data Monitor Display ................ EC-70 Removal and Installation of Ignition Coil
ECM Input/Output Signal Specifications ...... EC-70 (with Power Transistor) ................................ EC-77
Circuit Diagram ............................................ EC-70 Removal and Installation of Fuel Injector ..... EC-77
Component Parts Inspection ........................ EC-70 Removal and Installation of Fuel Pump ....... EC-77
THROTTLE CONTROL MOTOR SYSTEM ...... EC-71 Removal and Installation of Throttle Control
ECM Input/Output Signal Specifications ...... EC-71 Motor (Electric Throttle Control Actuator
Circuit Diagram ............................................ EC-71 Assembly) .................................................... EC-77
Component Parts Inspection ........................ EC-71 Removal and Installation of LPG Injector
HEATED OXYGEN SENSOR HEATER Holder .......................................................... EC-77
SYSTEM ............................................................ EC-72 Removal and Installation of LPG Injector
Service tool Data Monitor Display ................ EC-72 Drive Unit ..................................................... EC-78
ECM Input/Output Signal Specifications ...... EC-72 SERVICE DATA AND SPECIFICATIONS
Circuit Diagram ............................................ EC-72 (SDS) ................................................................ EC-79
Component Parts Inspection ........................ EC-72 Standard, Repair Limit ................................. EC-79
PCV GAS RECIRCULATION DEVICE ............. EC-73
 PRECAUTIONS

PRECAUTIONS General precautions for service operations

• Even when ignition switch is OFF, battery voltage may damage
the control unit. Turn ignition switch OFF and disconnect battery
ground cable before removing and installing control unit
harness.

GIM0059

• Be careful not to damage connector terminals when connecting

and disconnecting.Check the terminals for bend or breakage
before connecting.

ECM0010

• Check the input/output signal of terminal before replacing

control unit. Make sure that it operates normally.
Refer to EC-36, "ECM Input/Output Signal Specifications".

• Ensure the appropriate distance between test probes when

using a circuit tester. A longer distance is recommended,
because if the distance is too short, it may cause contact of test
probes, resulting in a short circuit. A short circuit allows battery
voltage to be applied directly to the control unit, resulting in
damage to its internal power transistors.

ECM0012

EC-3
 PREPARATION

PREPARATION Special Service Tools

Description Application

EGI fuel pressure indicator For measuring fuel pressure gauge

ST19590000

ECM0013

Heated oxygen sensor wrench Removing and installing heated oxygen sensor
KV10113700

ECM0014

DIAGNOSIS KIT For system inspection and diagnosis

29498 FK100

Check adapter V For control unit input/output signal inspection

EG1755000 (for SMJ 150-pin connector)

ECM0016

Harness adapter
EG17550200
(150-pin to 121-pin conversion adapter)

ECM0017

EC-4
 DESCRIPTION

DESCRIPTION • Adopts Electronic Concentrated engine Control System

(ECCS). Fuel injection control, ignition timing control, idle speed
control, and electronically controlled governor control etc. are all
performed by a single control unit.
• Adopts electric throttle control actuator system to control
electronically controlled governor.
• Adopts Hall IC type crankshaft position sensor (POS) and
camshaft position sensor (PHASE).
Items Description

Electric throttle control actuator • Adopts electronic throttle control actuator with integrated throttle control motor to adjust
throttle valve opening optimally according to driving conditions or to improve safety and
operability by electronically controlled governor.
Fuel injection control • With fuel injection control, air-fuel ratio is optimized to improve exhaust performance and
response.
• Using feedback control through learning of air-fuel ratio compensation, the system corrects
the ratio during transitional conditions, such as sudden sharp changes in the ratio, in order
to improve drivability.
Ignition timing control • Uses Hall IC crankshaft position sensor (POS) and camshaft position sensor (PHASE) to
perform controls so that optimum ignition timing is obtained for every operating condition.
Optimum ignition timing setup according to each fuel is also enabled at the time of a
combined use formula.
• Adopts electronic distribution system (NDIS) in which each cylinder is equipped with an
ignition coil incorporating a power transistor for better ignition performance.
Idle speed control • Adopts electronic throttle control actuator that continuously regulates intake air amount
required for idling.
Governor speed control • Performs maximum regulation of engine speed for oil pressure pump protection by engine
speed signal.
Maximum speed regulation control • Performs maximum speed regulation by vehicle speed sensor signal. Also, performs
variable control of maximum speed by changeover switch.
Idling area torque up control • Performs torque up control in idling area by engine speed signal in order to also enable
cargo work at idling.
Overheat prevention control • Reduces engine heat generation by reducing maximum engine speed and regulating
maximum throttle opening when engine coolant temperature reaches approximately 110°C
(230°F).
• Prevents resulting in engine breakage by overheat by performing fuel cut at 1,000 rpm or
more when engine coolant temperature reaches approximately 135°C (275°F).
Slow mode control • Changes throttle opening characteristic of throttle position by slow mode switch, and then
minute operation of engine speed is enabled. (Option setting)
Fuel pump control (gasoline) • Turns fuel pump relay ON/OFF depending on engine speed signal.
LPG interception valve control • Turns interception valve relay ON/OFF depending on engine speed signal and fuel
pressure sensor signal.
Fail-safe function • Ensures vehicle's safe operation and enables vehicle to be driven in an emergency when
any of the major system components (mass air flow sensor, engine coolant temperature
sensor, etc.) have malfunctioned.
Diagnostic system • Adopts self-diagnosis system for easier trouble diagnosis.

EC-5
DESCRIPTION

K-ENGINE ELECTRONIC CONTROLLED SYSTEM DIAGRAM

(GASOLINE)

ECM0376

EC-6
DESCRIPTION

K-ENGINE ELECTRONIC CONTROLLED SYSTEM DIAGRAM

(LPG)

ECM0377

EC-7
DESCRIPTION

K-ENGINE ELECTRONIC CONTROLLED SYSTEM DIAGRAM

(LPG AND GASOLINE)

ECM0378

EC-8
 DESCRIPTION

SENSORS AND ACTUATORS CONTROL ITEMS

Main sensors and actuators related to the ECM are listed below.

Combined
Gasoline std std std std — std std std std opt opt std std

Fuel

Fuel changing (Gasoline and LPG) Combined

LPG std std std — std std std std std opt opt std std

Control Item Fuel injection

control

Maximum vehicle speed control

Maximum engine speed control
PTC heater control in cold area

Loading speed control

Ignition timing control
Fuel injection control

A/F feedback control

Slow mode control

Fuel pump control

Idle speed control

Self-diagnosis
Fuel cut off

Fail-safe
⊕: Significant impact to control
♦: Impact to control
Crankshaft position sensor (POS,
⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ♦
PHASWE)
Mass air flow sensor ⊕ ⊕ ♦ ⊕ ♦ ♦
Intake air temperature sensor ♦ ⊕ ♦
Engine coolant temperature sensor ♦ ♦ ⊕ ♦ ♦ ♦ ♦
Heated oxygen sensor ⊕ ♦ ♦
Vehicle speed sensor ♦ ♦ ♦ ♦ ⊕ ♦
Throttle position sensor ♦ ♦ ⊕ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦
Accelerator pedal position sensor ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦
Sensors

Ignition switch ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕
P/N POSI SW ♦ ♦ ♦ ♦ ♦
Stop lamp switch ♦
Headlamp (electrical load) switch ♦
Slow mode switch (opt) ⊕
Battery voltage ♦ ♦ ♦ ♦ ♦ ♦
LPG fuel pressure sensor ♦ ⊕ ♦
LPG injector drive unit check signal ♦
Fuel changing switch ⊕ ⊕ ⊕ ⊕ ⊕

EC-9
 DESCRIPTION

Combined
Gasoline std std std std — std std std std opt opt std std

Fuel

Fuel changing (Gasoline and LPG) Combined

LPG std std std — std std std std std opt opt std std

Control Item Fuel injection

control

Maximum vehicle speed control

Maximum engine speed control
PTC heater control in cold area

Loading speed control

Ignition timing control
Fuel injection control

A/F feedback control

Slow mode control

Fuel pump control

Idle speed control

Self-diagnosis
Fuel cut off

Fail-safe
⊕: Significant impact to control
♦: Impact to control
Gasoline injector ⊕ ⊕ ⊕
Power transistor ⊕ ♦
Ignition
system Ignition coil ⊕
Throttle control motor relay ⊕ ⊕ ♦
Throttle control motor ⊕ ⊕ ♦ ♦
Gasoline fuel pump relay ⊕ ⊕
Gasoline fuel pump ⊕ ♦
Actuators

Ignition relay ⊕
ECM relay ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕
LPG injector drive unit ⊕ ⊕ ⊕
LPG injector ⊕ ⊕ ⊕ ♦
LPG assistance injector ⊕ ⊕ ⊕ ♦
LPG interception valve relay ⊕ ⊕ ♦
LPG interception valve ⊕ ♦
LPG PTC heater relay ♦ ⊕
LPG PTC heater ♦ ♦

EC-10
 BASIC INSPECTION

BASIC INSPECTION Inspection of Idle Speed, Ignition Timing,

and Air-fuel Ratio
STANDARD AT IDLE
Transaxle M/T A/T

Idle speed (neutral or N position) (rpm) 700±50 700±50

Ignition timing (°BTDC/rpm) 0±2/700 0±2/700
CO density (%) 0.1 or less
HC density (ppm) 50 or less

CAUTION:
Perform "Idle Air Volume Learning" (on page EC-13) when idle
speed or ignition timing is outside the standard.
• Turn ignition switch ON, and then make sure that no malfunction
is detected by self-diagnosis.
• Make sure that engine is free of oil pressure pump loads and
any electrical loads. Perform the inspection with the shift lever in
the neutral or N position.
• Warm up engine and transaxle to the normal operating
temperature.

IDLE SPEED
With Service tool
1. Connect Service tool to VCM connector.
2. Indicate "Eng.rev" in ECM Input/Output monitor and make sure
that idle speed is 700 ±50 rpm.

CAUTION:
Perform "Idle Air Volume Learning" (on page EC-13) when idle
speed is outside the standard.
Without Service tool
1. Connect an induction type (current detection type) tachometer
to the primary wire of the 1 cylinder to check idle speed.
• The primary wire for the 1 cylinder is looped and longer than the
wires for other cylinders. It is used for detecting idle speed and
ignition timing.
2. Make sure that idle speed is 700 ±50 rpm.

CAUTION:
Perform "Idle Air Volume Learning" (on page EC-13) when idle
speed is outside the standard.

EC-11
 BASIC INSPECTION

Inspection of Idle Speed, Ignition Timing,

and Air-fuel Ratio (Cont’d)
IGNITION TIMING INSPECTION
1. Install a timing light to the primary wire for 1 cylinder.
2. Make sure that ignition timing and idle speed are 0 ±2°BTDC/
700 rpm.

CAUTION:
Perform "Idle Air Volume Learning" (on page EC-13) when
ignition timing is outside the standard.

CO/HC DENSITY INSPECTION

The vehicle uses an air-fuel ratio feedback system with a self-
learning function. Because a wide compensation range is available,
no additional CO/HC density adjustment is necessary.
• Warm up engine to normal operating temperature. Confirm idle
speed and ignition timing are within the standards. Then, check
CO/HC density with a CO/HC measuring device.
• Check condition of air-fuel ratio feedback with the following
steps when measured values are outside the standard:

With Service tool

1. Indicate "O2 sensor rich" in ECM Input/Output monitor.
2. Keep engine speed at approximately 2,000 rpm, and make sure
that "ON" and "OFF" are alternately displayed.

ECM0024
Without Service tool
1. Check it with heated oxygen sensor monitor mode. (Refer to
EC-49, "DIAGNOSTIC TEST MODE II - HEATED OXYGEN
SENSOR MONITOR" for operation procedure.)
2. Keep engine speed at approximately 2,000 rpm, and make sure
that Engine Warning lamp blinks at least 5 times within 10
seconds.
NOTE:
• Increase engine speed when inspecting while air-fuel ratio feed-
back control is activated during idle.

EC-12
BASIC INSPECTION

Throttle Valve Closed Position Learning and

Idle Air Volume Learning
DESCRIPTION
When electric throttle control actuator or ECM connector is removed,
it is necessary for ECM to learn throttle valve closed position (throttle
position sensor output with throttle valve fully closed) after
reinstallation. Thus, throttle valve closed position learning is
performed.
When electric throttle control actuator or ECM is replaced, the
minimum required idle air volume needs to be learned. Thus, throttle
valve closed position learning and idle air volume learning are
performed.
Idle air volume learning is necessary even when idle speed or
ignition timing is outside the standard. Note that idle air volume
learning is equivalent to the base idle speed adjustment by
conventional throttle adjusting screw of carburetor or LPG mixer.

OPERATION PROCEDURE FOR THROTTLE VALVE CLOSED

POSITION LEARNING
1. Turn ignition switch ON → OFF. (And hold it for approximately 5
seconds after turning it OFF.)
2. Make sure that throttle valve operates. (Check for operating
sound.)
3. Upon completion of the above, learning is complete.

CAUTION:
Throttle valve closed position learning cannot be performed
with Service tool.

OPERATION PROCEDURE FOR IDLE AIR VOLUME LEARNING

1. Perform throttle valve closed position learning.
2. Fully warm up engine, transaxle, and lubricant. [Engine coolant
temperature: 70 to 90°C (158 to 194°F)]
3. Set the selector lever to neutral or N position. Make sure that
the engine is free of electrical loads, such as air conditioner, oil
pressure pump, and other electrical components.
4. Execute the following contents while idling using Service tool.

• Touch "OK" in "Idle Air Volume Learning (Normal)" of ECM

Active Test.

CAUTION:
"IDLE AIR VOL LEARN (PLANT)" is the original setting on the
vehicle. Do not use it.

EC-13
 BASIC INSPECTION

Throttle Valve Closed Position Learning and

Idle Air Volume Learning (Cont’d)
• When learning is completed, "CMPLT" is displayed.

CAUTION:
It will take approximately 20 seconds to complete the idle air
volume learning. Do not turn OFF the ignition switch until
completion.
• Confirm whether or not the learning has been completed by
checking the "TAS completion" in ECM Input/Output monitor.
Learning completed: ON
Learning not yet completed: OFF
ECM0027
• Make sure that idle speed and ignition timing are within the
standard.
• Perform "Idle Air Volume Learning" again if values are outside
the standard.

Accelerator Pedal Released Position

Learning
DESCRIPTION
When the accelerator pedal assembly has been replaced or the
accelerator pedal position sensor connector has been disconnected,
the accelerator pedal released position needs to be learned after
being repaired, so learn accelerator pedal in fully-released position.

OPERATION PROCEDURE
1. Turn ignition switch ON and wait at least 2 seconds.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Then turn ignition switch ON again and wait at least 2 seconds
(learning completed).

Fuel pressure inspection

QUICK INSPECTION
With Service tool
1. Turn ignition switch ON (engine stopped).
2. Press "OK" in "Fuel Pressure Release" of ECM Active Test.
3. Pinch the fuel feed hose with the fingers. Hose should not feel
hard.
Without Service tool
• When the fuel feed hose is squeezed while fuel pump is
operating (for 1 second after the ignition switch is turned ON or
while cranking), the hose should be swelling with pressure or
pulsating.

FUEL PRESSURE RELEASE

CAUTION:
Relieve fuel pressure before removing fuel piping to secure
safety.

EC-14
BASIC INSPECTION

Accelerator Pedal Released Position

Learning (Cont’d)
With Service tool
1. Start engine.
2. Select "Fuel Pressure Release" in ECM Active Test, and then
press "OK".
3. Crank engine 2 or 3 times to consume the fuel in the fuel line
after it stalls.
4. Turn ignition switch OFF.

Without Service tool

1. Disconnect fuel pump fuse.
2. Start engine.
3. Crank engine 2 or 3 times to consume the fuel in the fuel line
after it stalls.
4. Turn OFF the ignition switch, and install the fuel pump fuse.

FUEL PRESSURE INSPECTION

CAUTION:
• Safely and securely remove and install fuel hose.
• Use the fuel pressure gauge for fuel pressure inspection.
• Do not inspect fuel pressure while other systems are oper-
ating. Malfunctions may occur in fuel pressure value.
1. Release the fuel pressure.
2. Install fuel pressure gauge using fuel hose for fuel pressure
inspection.
3. Remove fuel hose, and then install fuel hose for fuel pressure
inspection.

CAUTION:
Usable period of fuel hose for fuel pressure inspection is 30
times or less. (Fuel hoses that are damaged and allow fuel
leakage are not contained above.)
4. Turn ignition switch ON, and then make sure that there is no fuel
leakage.
5. Start engine, and check for fuel leakage.
6. Make sure that fuel pressure is within the standard.
At idle: 353 kPa (3.53 bar, 3.6 kg/cm2, 51 psi)

• If the vehicle shows poor starting, check fuel pressure with fuel
pump operating for approximately 1 second after ignition switch
is turned ON, and during cranking.
For 1 second after ignition switch is turned ON and
during cranking: 353 kPa (3.53 bar, 3.6 kg/cm2, 51
psi)

• Check the following items if a malfunction is detected.

CAUTION:
Also check fuel pressure at increased engine speed.
• Malfunctioning pressure regulator (integrated with fuel pump)
• Clogged fuel piping
• Clogged fuel filter (with fuel pump)
• Poor fuel pump discharge

EC-15
 TROUBLE DIAGNOSIS

TROUBLE DIAGNOSIS How to Proceed with Trouble Diagnosis

1. The most important point in performing trouble diagnosis of
malfunctions is to thoroughly understand the vehicle systems
(both control and mechanical).
An ECM-based engine controls actuators such as injectors and
the ignition coil according to information from sensors. Then
through actuator operation, the engine (mechanical system)
runs. Sensors transmit information on the running condition,
which changes constantly, to ECM. It is important to under-
stand these cycles.
ECM0031

2. It is also important to clarify customer concerns before starting

the inspection.
First of all, reproduce the symptom, and understand it fully.
Ask the customer about his/her concerns carefully. In some
cases, it will be necessary to check the symptoms by driving
the vehicle with the customer.

CAUTION:
Customers are not professionals. Do not assume "maybe the
customer means ..." or "maybe the customer mentioned this
ECM0032 symptom".

3. It is essential to confirm symptoms right from the beginning in

order to ensure all malfunctions are completely repaired.
For an intermittent malfunction, it is important to reproduce the
symptom based on an interview with the customer and past
examples. Do not perform an inspection on an ad hoc basis.
Most intermittent malfunctions are caused by poor contacts. In
this case, it will be effective to shake the suspected harness or
connector by hand. When repairs are performed without any
symptom check, no one can judge if the malfunction has actu-
ally been eliminated.
ECM0033
4. The next important thing is to find which system among the
following is causing the malfunction: ECM control signal system,
or a mechanical system (such as the engine main body and
auxiliary component). It is important to inspect the system using
Service tool or by checking the ECM input/output signals. When
checking the ECM input/output signals, connect a check
adapter (Service tool) to ECM in order to prevent misdiagnosis.
Special Service Tools (Service tool):
Check adapter V (EG17530000) (for SMJ 150-pin con-
nector)
Harness adapter (EG17550200) (150-pin → 121-pin
conversion adapter)

EC-16
 TROUBLE DIAGNOSIS

How to Proceed with Trouble Diagnosis

(Cont’d)
5. Use the reference value of input/output data (guideline) in this
manual in order to judge the ECM input/output signals. Measure
the data of another vehicle of the same model under the same
conditions when it is difficult to judge, and compare the data. It
is advisable to collect sufficient data of a normally operating
vehicle.

ECM0034

TROUBLE DIAGNOSIS FLOW CHART

There are many different malfunction symptoms. So there is no
perfect trouble diagnosis technique applicable to all malfunctions.
Experience is also important to achieving an accurate trouble
diagnosis.
Nonetheless, an accurate trouble diagnosis can be performed by
applying similar procedures, regardless of the malfunction symptom.
Perform trouble diagnosis following the flow chart shown below.

ECM0035

EC-17
 TROUBLE DIAGNOSIS

How to Proceed with Trouble Diagnosis

(Cont’d)
DIAGNOSTIC WORK SHEET
Description
• In order to clarify the malfunction symptom, it is important to ask
the customer and collect information about their concerns.
• Ask the customer about what symptoms are present under what
conditions. Use the information to clarify the symptom.
• Use the trouble diagnosis sheet to be certain not to miss any
vital information.

ECM0036

EC-18
TROUBLE DIAGNOSIS

How to Proceed with Trouble Diagnosis

(Cont’d)

ECM0037

EC-19
 TROUBLE DIAGNOSIS

Diagnosis Chart by Symptom

RELATIONSHIP BETWEEN MALFUNCTIONING SYMPTOMS
AND THE SENSOR CIRCUIT
The table below shows the possible symptoms caused by the
malfunction of each sensor circuit.

Poor starting
Impossible

Check that symptoms are detected with self-diagnosis.

to start

Engine

Other
Symptoms Poor idle Poor driving control

Check that symptoms are in fail-safe condition.

stall

During surge and constant speed driving

Engine rpm does not increase smoothly.
Inconsistent idle when engine is cold.

Engine over temperature (Overheat)

Inconsistent idle when warming up

Poor fuel consumption efficiency

During surge and acceleration
When engine is warming up

Description/notable
Fast idle is not effective
No initial combustion

characteristics of the
When engine is cold

During a heavy load

During deceleration
Poor power output
Poor acceleration
Initial combustion

symptom
High idle rpm
Low idle rpm

After-burn
Knocking
Backfire

Driving
At Idle
Sensor malfunction
⊕: Highly possible
♦: Possible

Crankshaft position sensor OPEN ⊕ ⊕ ⊕ ⊕ ⊕ ♦ • An open circuit in either REF or

(POS, PHASE) POS signal makes it impossible
for the vehicle to start.
• Control signals for fuel system
and ignition system are not
output.

Momentarily ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ⊕ ♦ ♦ ♦ ♦ • The symptom depends on the

open duration of momentarily open
circuit and the operating
conditions. Slight shocks and
surges may be sensed during
driving, while engine stall may
be caused during idle.

Mass air flow Signal OPEN ♦ ♦ ⊕ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • It will be in fail-safe condition,

sensor and vehicle runs at an engine
speed of 2,400 rpm or less.

High output ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • The air-fuel ratio becomes rich.

Black smoke may accompany.
Poor connection of grounding
may be a possible cause.

Low output ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • The air-fuel ratio becomes lean.

Contaminated hot wire or
suction of air may be suspected.

Ground OPEN ⊕ ⊕ ⊕ ⊕ ⊕ ♦ • It will be over-rich.

Power OPEN ♦ ♦ ⊕ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • It will be in fail-safe condition,

supply and vehicle runs at an engine
speed of 2,400 rpm or less.

Intake air temperature OPEN/ ♦

sensor SHORT

Engine coolant temperature OPEN/ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • will be in fail-safe condition, and

sensor SHORT then Engine Warning lamp turns
ON. This malfunction tends to
occur when engine is cold or
when the engine coolant
temperature is high.

Resistance ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • The engine coolant temperature

is large. is judged as low. This
malfunction tends to occur after
warming up.

Resistance ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • The engine coolant temperature

is small. is judged as high. This
malfunction tends to occur when
engine is cold.

Heated oxygen sensor OPEN/ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • It will be base air-fuel ratio.

SHORT

Vehicle speed sensor OPEN/ ♦ ♦ ♦ ♦ • Duration of fuel cut becomes

SHORT shorter or fuel may not be cut.

EC-20
 TROUBLE DIAGNOSIS

Poor starting

Check that symptoms are detected with self-diagnosis.

Impossible
to start
Engine

Other
Symptoms Poor idle Poor driving control

Check that symptoms are in fail-safe condition.

stall

During surge and constant speed driving

Engine rpm does not increase smoothly.
Inconsistent idle when engine is cold.

Engine over temperature (Overheat)

Inconsistent idle when warming up

Poor fuel consumption efficiency

During surge and acceleration
When engine is warming up
Description/notable

Fast idle is not effective

No initial combustion
characteristics of the

When engine is cold

During a heavy load

During deceleration
Poor power output
Poor acceleration
Initial combustion
symptom

High idle rpm

Low idle rpm

After-burn
Knocking
Backfire

Driving
At Idle
Sensor malfunction
⊕: Highly possible
♦: Possible

Throttle position sensor OPEN/ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • Idle will be base rpm. No

SHORT addition for acceleration.

Output ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • Possible interruption by

fluctuation unnecessary fuel injection. Poor
ground or control unit
connection may be the cause.

Poor ♦ ♦ • Idling is judged as OFF during

adjustment idle. Turning ignition switch
repeatedly to ON and OFF will
set the system to normal.

Accelerator pedal position OPEN/ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦

sensor SHORT

Output ♦ ♦ ♦ ♦ ♦ ♦ ♦
fluctuation

Ignition switch IGN OPEN ⊕ ⊕ ⊕ ⊕ ⊕ • Impossible to start without

outputs for fuel and ignition
systems.

P/N POSI SW OPEN ♦ ⊕ ♦ ⊕ ♦ ♦ ♦ • PNP switch is judged as OFF,

and the target cold engine
speed in N/P position is
lowered.

SHORT • PNP switch is judged as ON,

and fast idle is effective for cold
engine in positions other than N/
P position, making the creep
larger.
Stop lamp switch OPEN/
SHORT

Headlamp (electrical load) OPEN/ ♦ ♦

switch SHORT

CAN communication line OPEN/

SHORT

Power supply for ECM OPEN ⊕ ⊕ ⊕ ⊕ ⊕ ♦ • Impossible to start without

outputs for fuel and ignition
systems.

Sensor ground (coolant OPEN/ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • The same as the open circuit in

temperature sensor, throttle SHORT the applicable sensor.
position sensor)
Control unit and connector Poor ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • A slightly raised connector often
connection, results in poor connection. Entry
water entry? of water causes engine stall,
and afterwards it is momentarily
impossible to restart engine. In
some cases, restarting is
possible after a short wait.

LPG fuel pressure sensor OPEN/ ♦

SHORT

LPG injector Check OPEN

drive unit signal
line SHORT

Fuel changing switch OPEN • Fuel changing cannot be done.

EC-21
 TROUBLE DIAGNOSIS

RELATIONSHIPS BETWEEN MALFUNCTIONING SYMPTOMS

AND ACTUATOR CIRCUITS
The table below shows the possible symptoms caused by the
malfunction of each actuator circuit.

Poor starting

Check that symptoms are detected with self-diagnosis.

Impossible
to start
Engine

Other
Symptoms Poor idle Poor driving

Check that symptoms are in fail-safe condition.

stall

During surge and constant speed driving

Engine rpm does not increase smoothly.
Inconsistent idle when engine is cold.

Engine over temperature (Overheat)

Inconsistent idle when warming up

Poor fuel consumption efficiency

During surge and acceleration
When engine is warming up

Description/notable
Fast idle is not effective
No initial combustion

characteristics of the
When engine is cold

During a heavy load

During deceleration
Poor power output
Poor acceleration
Initial combustion

symptom
High idle rpm
Low idle rpm

After-burn
Knocking
Backfire

Driving
At Idle
Actuator malfunction
⊕: Highly possible
♦: Possible

Gasoline injector Power OPEN ♦ ♦ ♦ ♦ ⊕ ⊕ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • No fuel injection to cylinder with

supply open circuit, resulting in LEAN
circuit Momentarily ♦ ♦ ♦ ♦ output of heated oxygen
open sensors.
• Starting engine is impossible
Coil OPEN ♦ ♦ ♦ ♦ ⊕ ⊕ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ when the circuits for all the
cylinders are open.
Momentarily ♦ ♦ ♦ ♦
open

Drive OPEN ♦ ♦ ♦ ♦ ♦ ⊕ ⊕ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦
circuit
(ECM Momentarily ♦
side) open

SHORT ♦ ♦ ♦ ♦ ⊕ ⊕ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • Continuous fuel injection to

cylinder with short circuit,
resulting in OVER-RICH and
misfiring.
• Starting engine is impossible
when the circuits for all the
cylinders are open.

Nozzle Foreign ♦ ♦ ♦ ♦ ⊕ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • The cylinder with foreign

hole material material will keep injecting.
intrusion

Clogging ♦ ♦ ♦ ♦ ♦ ⊕ ⊕ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • The symptom depends on

clogging status. The correction
factor of air-fuel ratio becomes
larger.

Ground OPEN ♦ ♦ ♦ ♦ ♦ • Shocks may be sensed and

circuit engine stall may be occur
(ECM) depending on the duration of the
operation conditions.

Momentarily ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦
open

Ignition signal circuit OPEN ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • Slight shocks and surges may

be sensed depending on the
Momentarily ♦ ♦ ♦ duration of momentarily open
open circuit and the operating
conditions.

Ignition coil Power OPEN ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ •

supply
circuit Momentarily ♦ ♦ ♦ • Engine stall may occur if
open duration of momentarily open
circuit is too long.

Coil OPEN ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • Shocks may be sensed and

engine stall may be occur
depending on the duration of the
operation conditions.

Ground OPEN ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • Injects fuel toward spark plug on

circuit the cylinder with open circuit.

Momentarily ♦ ♦ ♦
open

ECM relay circuit OPEN ⊕ ♦ ⊕ ⊕ ⊕ ⊕

EC-22
 TROUBLE DIAGNOSIS

Poor starting

Check that symptoms are detected with self-diagnosis.

Impossible
to start
Engine

Other
Symptoms Poor idle Poor driving

Check that symptoms are in fail-safe condition.

stall

During surge and constant speed driving

Engine rpm does not increase smoothly.
Inconsistent idle when engine is cold.

Engine over temperature (Overheat)

Inconsistent idle when warming up

Poor fuel consumption efficiency

During surge and acceleration
When engine is warming up
Description/notable

Fast idle is not effective

No initial combustion
characteristics of the

When engine is cold

During a heavy load

During deceleration
Poor power output
Poor acceleration
Initial combustion
symptom

High idle rpm

Low idle rpm

After-burn
Knocking
Backfire

Driving
At Idle
Actuator malfunction
⊕: Highly possible
♦: Possible

Throttle control motor circuit OPEN/ ♦ ♦ ♦ ♦ ♦ ♦

SHORT

Throttle motor relay circuit OPEN ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • The same malfunction may

occur as power supply open of
throttle control motor and
throttle position sensor.

Heated oxygen sensor OPEN

heater circuit

• Fuel pump relay circuit OPEN ⊕ ⊕ ⊕ ⊕ ⊕ • Impossible to start

• Fuel pump circuit
• Ignition relay circuit Momentarily ♦ ♦ ♦ ♦ ♦ • Impossible to start
open

Fuel pump OPEN/ ♦ ♦ ♦ ♦

Pressure regulator SHORT

LPG injector Ti OPEN

drive unit circuit
SHORT

Tip OPEN
circuit
SHORT

PWM OPEN
circuit
SHORT

Power OPEN
supply

Ground OPEN

LPG injector HI side OPEN

circuit
SHORT

Coil OPEN

LO side OPEN
circuit
SHORT

LPG assistance injector OPEN

Control unit
side short

LPG interception valve relay OPEN

Control unit
side short

LPG interception valve OPEN

LPG PTC heater relay OPEN/

SHORT

Malfunction indicator lamp OPEN

Improper TAS learning OPEN ♦ ♦ ♦ ♦ ♦ ♦ ♦

EC-23
 TROUBLE DIAGNOSIS

RELATIONSHIP BETWEEN MALFUNCTIONING SYMPTOM AND

THE ENGINE MAIN BODY/AUXILIARY COMPONENT
The table below shows the possible symptoms caused by the
malfunction of engine main body system. It will be helpful in
malfunction trouble diagnosis. (The table lists general symptoms and
some may not be applicable.)

Poor starting
Impossible
to start
Engine

Other
Symptoms Poor idle Poor driving
stall

During surge and constant speed driving

Engine rpm does not increase smoothly.
Inconsistent idle when engine is cold.

Engine over temperature (Overheat)

Inconsistent idle when warming up

Poor fuel consumption efficiency

During surge and acceleration
When engine is warming up
Fast idle is not effective

Description/notable
No initial combustion

When engine is cold

During a heavy load

During deceleration
Poor power output
Poor acceleration characteristics of the symptom
Initial combustion

High idle rpm

Low idle rpm

After-burn
Knocking
Backfire

Driving
At Idle
⊕: Highly possible
♦: Possible
∇: Not very possible
Air sucked from oil level gauge ♦ ∇ ♦ ♦ ∇ ∇ ∇ • Air-fuel ratio becomes LEAN.
• High air-fuel correction factor.
Air sucked from oil filler cap ♦ ∇ ♦ ♦ ∇ ∇ ∇ • Low suction power (vacuum pressure) of
intake manifold.
Air sucked from PCV hose ♦ ∇ ♦ ∇ ♦ ♦ ♦ ♦ ♦ ∇ ∇ ♦ ♦ ♦ ∇ * Check the suction using a pressure
(downstream of PCV) gauge.
* Generally applicable to air suction in air
Air sucked from intake manifold and ♦ ∇ ♦ ∇ ♦ ♦ ♦ ♦ ♦ ∇ ∇ ♦ ♦ ♦ ∇ intake system
gasket

PCV kept open ♦ ♦ ∇ ♦ ♦ ♦ ♦ ♦ • Noise (high hissing tone)

Clogged fuel strainer ♦ ∇ ♦ ∇ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ∇ ♦ ♦ • Symptom depends on clogging status.

This tends to happen during high-speed
Clogged air cleaner element ♦ ♦ ♦ ♦ ♦ ♦ or high load operation.

Malfunctioning gasoline pressure ∇ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • Symptom varies depending on

regulator combustion pressure.
Fuel mixture

Poor quality gasoline ∇ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ∇ ♦ ♦ ♦ ♦ ∇ • Symptom varies depending on oil quality.

Improper LPG fuel (cold area and ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ∇ ♦ ♦ ♦ ♦ ∇ • Starting ability in cold area is changed
propane ratio) depending on propane ratio.
• Use LPG with proper propane ratio.

Malfunctioning LPG vaporizer ∇ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • If the pressure is low, it is caused by poor

pressure adjusting valve output during high-speed or high load
operation.
• If the pressure is excessively high, relief
valve operates and engine stalls at rich.

Clogged LPG vaporizer hot water ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • Symptom depends on fuel temperature.

circuit This tends to happen during engine stall
and is impossible to restart during engine
warming up.

Clogged LPG interception valve ♦ ∇ ♦ ∇ ♦ ♦ ♦ ♦ ♦ ∇ ♦ ∇ • Symptom depends on clogging status.

filter This tends to happen during high-speed
or high load operation.

Valve deposit ♦ ♦ ♦ ∇ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ∇ • Air-fuel ratio becomes LEAN. High air-

fuel correction factor.

Improper connection of wire ∇ ∇ ∇ ∇ ∇ ∇ ∇ ∇ ∇ ∇ ∇ ∇ ∇ ∇ ∇ ∇ ∇ ∇ • Check that wiring route is proper.

connector

Poor connection of wire connector ∇ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • Check that connector is slightly raised.

Poor starting if slightly raised connectors
are in all cylinders.
Sparking

Improper ignition timing adjustment ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ —

Malfunctioning spark plug ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ∇ ∇ ∇ • Check that the gap is proper. Check

spark plug for electric wear, soil (fuel
injection, smoking), and damaged
insulator.

Leakage from high-pressure parts ∇ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • Symptom varies depending on the level

of leakage.

EC-24
 TROUBLE DIAGNOSIS

Poor starting
Impossible
to start
Engine

Other
Symptoms Poor idle Poor driving
stall

During surge and constant speed driving

Engine rpm does not increase smoothly.
Inconsistent idle when engine is cold.

Engine over temperature (Overheat)

Inconsistent idle when warming up

Poor fuel consumption efficiency

During surge and acceleration
When engine is warming up
Fast idle is not effective
Description/notable
No initial combustion

When engine is cold

During a heavy load

During deceleration
Poor power output
characteristics of the symptom

Poor acceleration
Initial combustion

High idle rpm

Low idle rpm

After-burn
Knocking
Backfire

Driving
At Idle
⊕: Highly possible
♦: Possible
∇: Not very possible
Improper bulb contact ∇ ♦ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ♦ ♦ ♦ ♦ ♦ • Symptom varies depending on contact
Compression

condition and the number of cylinders.

pressure

Worn piston ring ∇ ♦ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ♦ ♦ ♦ ♦ • Symptom varies depending on degree of

wear and the number of cylinders.

Clogged three-way catalytic ∇ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • In some cases, after engine stall,

converter /exhaust system restarting is possible.

Low idle base speed ∇ ∇ ∇ ∇ ♦ ♦ ♦ ♦ • Engine stall may occur by power steering
load and cargo load during deceleration
or at idling.

Dragging of brakes ♦ ♦ ♦ ♦ • Tires/wheels are hot.

Belt tension too high (excessive ♦ ♦ ♦ ♦ ♦ —

tension)

High A/C load ♦ ♦ ∇ ∇ ∇ ∇ ∇ ♦ ∇ ♦ ♦ ♦ • Too much refrigerant

∇ ∇ ♦ ∇ ♦
Other

High A/T load • Insufficient ATF amount, improper oil

specification (This symptom may
especially occur in the cold.)

High HYD PUMP load (PS, Cargo) ∇ ∇ ∇ ♦ ♦ ∇ ∇ ∇ ♦ • Malfunctioning oil pressure relief valve,
improper oil specification (This symptom
may especially occur in the cold.)

Foreign material in fuel tank (such ∇ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ • With low fuel, this may easily occur.
as dust)

Damaged fan, malfunctioning water ♦ • Noise

pump
Clogged/restricted radiator/ ♦ —
condenser

Also check the following items other than the above:

• Check harness tension.
• Check each connector connection.
• Check ground wire for looseness.
• Check battery connection for looseness or corrosion.
• Check water and oil condition.
• Check fan belts for looseness.

EC-25
 TROUBLE DIAGNOSIS

Component Parts Location

ECM0038

Specifications
Main component part Type Location
Gasoline LPG Combined

Actuators Gasoline injector High resistance Intake manifold ○ ○

LPG injector Gas injection Integrated in injector ○
holder (on intake
manifold)
Fuel pump Electric motor/turbine Integrated in fuel tank ○ ○
Fuel pressure regulator Diaphragm ○ ○
Throttle control motor Electric DC motor (DC Integrated in electronic ○ ○ ○
motor) throttle control actuator
Ignition coil Mold (built-in power Cylinder head (On each ○ ○ ○
transistor) spark plug)

EC-26
 TROUBLE DIAGNOSIS

Component Parts Location (Cont’d)

Specifications
Main component part Type Location
Gasoline LPG Combined

Sensors Crankshaft Crankshaft Hall IC (element) Front cover ○ ○ ○

position position sensor
sensor (POS)
Camshaft position Chain housing ○ ○ ○
sensor (PHASE)
Mass air flow sensor Hot wire Air horn ○ ○ ○
Accelerator pedal position Variable resistance Integrated in accelerator ○ ○ ○
sensors 1 and 2 work unit (accelerator
pedal assembly)
Throttle position sensors 1 and 2 Integrated in electronic ○ ○ ○
throttle control actuator
Engine coolant temperature Thermistor Water outlet ○ ○ ○
sensor
Intake air temperature sensor With air flow meter ○ ○ ○
Heated oxygen sensor Zirconia (with heater) Front tube ○ ○ ○
ECM 121-pin digital control Vehicle side ○ ○ ○
ECM & IGN coil relay Compact general relay Vehicle side ○ ○ ○
(1M X 2)

ECM Component
Specifications NOTE
Component Location
Gasoline LPG Combined Actuator Sensor Other
Gasoline injector Intake manifold ○ ○ ○
LPG injector Integrated in injector holder (on ○ ○ ○
intake manifold)
Throttle control motor Integrated in electronic throttle ○ ○ ○ ○
control actuator
Throttle position sensors 1 and 2 ○ ○ ○ ○
Ignition coil Cylinder head (on each spark plug) ○ ○ ○ ○
Crankshaft position sensor (POS) Front cover ○ ○ ○ ○
Camshaft position sensor (PHASE) Front housing ○ ○ ○ ○
Mass air flow sensor Air horn ○ ○ ○ ○
Intake air temperature sensor With air flow meter ○ ○ ○ ○
Engine coolant temperature sensor Water outlet ○ ○ ○ ○
Accelerator pedal position sensors Integrated in accelerator work unit ○ ○ ○ ○
1 and 2 (accelerator pedal assembly)
Fuel pump Integrated in fuel tank ○ ○ ○
Fuel pressure regulator ○ ○ ○
Heated oxygen sensor (Vehicle side) ○ ○ ○ ○
Vehicle speed sensor (Vehicle side) ○ ○ ○ ○
ECM (Vehicle side) ○ ○ ○ ○
ECM & IGN coil relay (Vehicle side) ○ ○ ○ ○
Stop lamp switch (Vehicle side) ○ ○ ○ ○
Throttle control motor relay (Vehicle side) ○ ○ ○ ○
Fuel pump relay (Vehicle side) ○ ○
Vaporizer (Vehicle side) ○ ○ ○
LPG interception valve (Vehicle side) ○ ○ ○

EC-27
TROUBLE DIAGNOSIS

ECM Component (Cont’d)

ECM0039

EC-28
TROUBLE DIAGNOSIS

ECM Component (Cont’d)

ECM0040

EC-29
TROUBLE DIAGNOSIS

Circuit Diagram
K-ENGINE ELECTRONIC CONTROLLED ECM CIRCUIT DIA-
GRAM (GASOLINE)

ECM0379

EC-30
TROUBLE DIAGNOSIS

Circuit Diagram (Cont’d)

K-ENGINE ELECTRONIC CONTROLLED ECM CIRCUIT DIA-
GRAM (LPG)

ECM0380

EC-31
TROUBLE DIAGNOSIS

Circuit Diagram (Cont’d)

K-ENGINE ELECTRONIC CONTROLLED ECM CIRCUIT DIA-
GRAM (COMBINED GASOLINE AND LPG)

ECM0381

EC-32
 TROUBLE DIAGNOSIS

ECM Terminal Layout

ECM0044

The symbol in ( ) next to terminal numbers indicates the data link

connector.
Terminal Description

24 Heated oxygen sensor heater

2 —
6 —
7 —
8 LPG injector
9 —
113 Gasoline F/P relay
11 LPG assistance injector
12 —
15 —
16 —
17 —
18 —
19 —
111 Self shut-off
62 Ignition signal No. 1
81 IGN-COIL #2
61 Ignition signal No. 3
80 Ignition signal No. 4
25 —
27 PTC heater relay
28 —
29 —
30 —
31 LPG fuel pressure sensor
32 Fuel changing switch 2 (Gasoline)
94 CAN communication line H
86 CAN communication line L
36 —
37 —
38 —
39 LPG injector drive keeping
101 Brake switch
109 (IGN) Ignition switch

EC-33
 TROUBLE DIAGNOSIS

ECM Terminal Layout (Cont’d)

Terminal Description

102 PNP switch

100 —
45 —
46 —
47 Electric throttle control actuator open
49 Fuel changing switch power supply
85 (K LINE) Signal line for service
52 —
84 Headlamp switch
54 —
55 —
56 —
57 —
67 Sensor ground
115 (-) ECM ground
116 (-) ECM ground
13 Crankshaft position sensor (POS)
63 —
91 Accelerator pedal position sensor 2 power supply
48 Sensor power supply
121 Power supply (backup)
68 —
70 Fuel changing switch 1 (LPG)
14 Camshaft position sensor (PHASE)
51 Mass air flow sensor
50 Throttle position sensor 1
69 Throttle position sensor 2
106 Accelerator pedal position sensor 1
98 Accelerator pedal position sensor 2
77 —
78 Heated oxygen sensor ground
79 —
34 Intake air temperature sensor signal
83 Accelerator pedal position sensor 2 ground
87 —
88 —
89 —
35 Heated oxygen sensor
92 —
73 Engine coolant temperature sensor signal
95 —
23 Injector No. 1
42 Injector No. 2
22 Injector No. 3
41 Injector No. 4
105 —
107 —

EC-34
 TROUBLE DIAGNOSIS

ECM Terminal Layout (Cont’d)

Terminal Description

108 —
119 Power supply for ECM
110 —
120 Power supply for ECM
104 Throttle control motor relay
3 Throttle control motor relay power supply
5 Throttle control motor (Open)
4 Throttle control motor (Close)
1 ECM ground
10 —
20 —
21 —
26 —
33 —
40 —
43 —
44 LPG injector drive intake
53 —
58 —
59 —
60 —
64 —
65 —
66 Sensor ground (Throttle position sensor)
71 —
72 LPG injector check
74 —
75 —
76 —
82 Accelerator pedal position sensor 1 ground
90 Accelerator pedal position sensor 1 power supply
93 —
96 —
97 —
99
103 —
112 LPG interception valve relay
114 —
117 —
118 —

EC-35
 TROUBLE DIAGNOSIS

ECM Input/Output Signal Specifications

REFERENCE VALUE LIST
• Voltage is measured with a circuit tester, and the sample
waveforms obtained with an oscilloscope are shown below for
each ECM terminal. Measurement data varies depending on
variation in parts as well as many other factors. Such factors
include vehicle history, driving conditions, environmental
conditions, maintenance status, measuring instrument/method,
etc. Data shown below are reference values.

ECM0044

Terminal
Signal name Measurement condition Measured value
signal

24 Heated oxygen sensor heater At idle after warming up Approx. 0.3V

113 Gasoline F/P relay For approximately 1 second after ignition Approx. 1V
switch ON
After that Battery voltage
At cranking, engine running Approx. 1V
111 Self shut-off For approximately 10 seconds with Approx. 1V
ignition switch ON and after ignition
switch OFF
Ignition switch OFF Battery voltage

EC-36
 TROUBLE DIAGNOSIS

ECM Input/Output Signal Specifications

(Cont’d)
Terminal
Signal name Measurement condition Measured value
signal

61 Ignition signal (power transistor drive At cranking Approx. 0.2V

62 signal)
80
81

ECM0047

At idle after warming up Approx. 0.1V

ECM0048

At approx. 2,000 rpm Approx. 0.1V

ECM0049

94 CAN communication line H Always Approx. 2.4V (Varies depending on

communication status.)

ECM0050

86 CAN communication line L Always Approx. 2.2V (Varies depending on

communication status.)

ECM0051

101 Brake switch Brake pedal released Approx. 0V

Brake pedal depressed Battery voltage
109 (IGN) Ignition switch Ignition switch OFF Approx. 0V
Ignition switch ON Battery voltage
102 PNP switch Neutral, or N position Approx. 0V
Other than above Battery voltage (A/T models)
Approx. 4.8V (M/T models)

EC-37
 TROUBLE DIAGNOSIS

ECM Input/Output Signal Specifications

(Cont’d)
Terminal
Signal name Measurement condition Measured value
signal

85 (K LINE) Signal line for service When connected to Service tool Approx. 6.6 - Battery voltage
When not connected to Service tool Approx. 6V
84 Headlamp switch Lighting switch OFF Approx. 0V
Lighting switch ON Battery voltage
67 Sensor ground Always Approx. 0V
115 ECM ground Always Approx. 0V
116
1
13 Crankshaft position sensor (POS) At cranking Approx. 2.6V

ECM0052

At idle after warming up Approx. 3V

ECM0053

At approx. 2,000 rpm Approx. 3V

ECM0054

91 Accelerator pedal position sensor 2 Ignition switch ON, engine running Approx. 2.5V
power supply
48 Sensor power supply Ignition switch ON, engine running Approx. 5V
121 Power supply (backup) Always Battery voltage
47 Electric throttle control actuator open Ignition switch ON, engine running Approx. 5V
78 Heated oxygen sensor ground Always Approx. 0V
82 Accelerator pedal position sensor 1 Always Approx. 0V
ground
90 Accelerator pedal position sensor 1 Ignition switch ON, engine running Approx. 5V
power supply

EC-38
 TROUBLE DIAGNOSIS

ECM Input/Output Signal Specifications

(Cont’d)
Terminal
Signal name Measurement condition Measured value
signal

14 Camshaft position sensor (PHASE) At cranking Approx. 0.15V

ECM0055

At idle after warming up Fluctuates between approx. 1.5 - 2V.

ECM0056

At approx. 2,000 rpm Approx. 2V

ECM0057

51 Mass air flow sensor Ignition switch ON Approx. 1V

At cranking Approx. 1.5V
At idle after warming up Approx. 1.3V
At approx. 2,000 rpm Approx. 1.5V
50 Throttle position sensor 1 At idle after warming up Approx. 0.6V
Ignition switch ON with engine stopped Approx. 0.75V
Accelerator pedal is fully depressed
Ignition switch ON with engine stopped Approx. 0.75V
Accelerator pedal is released
At approx. 2,000 rpm Approx. 0.7V
69 Throttle position sensor 2 At idle after warming up Approx. 4.5V
Ignition switch ON with engine stopped Approx. 4.35V
Accelerator pedal is fully depressed
Ignition switch ON with engine stopped Approx. 4.35V
Accelerator pedal is released
At approx. 2,000 rpm Approx. 4.4V
106 Accelerator pedal position sensor 1 At Idle Approx. 0.6V
Ignition switch ON with engine stopped Approx. 0.6V
Accelerator pedal is fully depressed
Ignition switch ON with engine stopped Approx. 4.2V
Accelerator pedal is released
At approx. 2,000 rpm Approx. 0.65V

EC-39
 TROUBLE DIAGNOSIS

ECM Input/Output Signal Specifications

(Cont’d)
Terminal
Signal name Measurement condition Measured value
signal

98 Accelerator pedal position sensor 2 At Idle Approx. 0.3V

Ignition switch ON with engine stopped Approx. 0.3V
Accelerator pedal is fully depressed
Ignition switch ON with engine stopped Approx. 2V
Accelerator pedal is released
At approx. 2,000 rpm Approx. 0.35V
34 Intake air temperature sensor signal Intake air temperature is approx. 20°C Approx. 3.5V
(68°F).
Intake air temperature is approx. 80°C Approx. 1.2V
(176°F).
83 Accelerator pedal position sensor 2 Always Approx. 0V
ground
35 Heated oxygen sensor At idle after warming up Changes between approx. 0.1 -
0.4V⇔;approx. 0.6 - 0.9V

ECM0058

At approx. 2,000 rpm Changes between approx. 1 -

0.4V⇔;approx. 0.6 - 0.9V

ECM0059

73 Engine coolant temperature sensor Engine coolant temperature is approx. Approx. 3.5V
signal 20°C (68°F).
Engine coolant temperature is approx. Approx. 1.2V
80°C (176°F).

EC-40
 TROUBLE DIAGNOSIS

ECM Input/Output Signal Specifications

(Cont’d)
Terminal
Signal name Measurement condition Measured value
signal

22 Injector drive signal At cranking Approx. 10.5V

23
41
42

ECM0060

At idle after warming up Battery voltage

ECM0061

At approx. 2,000 rpm Relatively lower than battery voltage

ECM0062

119 Power supply for ECM Ignition switch ON, engine running Battery voltage
120
104 Throttle control motor relay Ignition switch ON, engine running Approx. 1V
3 Throttle control motor relay power supply Always Battery voltage
5 Throttle control motor (Open) At idle after warming up Approx. 0.1 - 0.15V
At approx. 2,000 rpm
4 Throttle control motor (Close) At idle after warming up Approx. 2 - 2.5V
At approx. 2,000 rpm
11 LPG assistance injector Other than above (Ignition switch ON, Battery voltage
engine running)
27 PTC heater relay Other than above (Ignition switch ON, Battery voltage
engine running)
32 Fuel changing switch 2 (Gasoline) Changing switch ON (At gasoline side) Approx. 5V
Changing switch ON (At LPG side or Approx. 0V
neutral)
49 Fuel changing switch power supply Changing switch ON Approx. 5V
Changing switch ON (At neutral) Approx. 0V
70 Fuel changing switch 1 (LPG) Changing switch ON (At LPG side) Approx. 5V
Changing switch ON (At LPG side or Approx. 0V
neutral)
112 LPG interception valve relay For approximately 10 seconds with Battery voltage
ignition switch ON and after ignition
switch OFF
Ignition switch OFF Approx. 0V

Numerical values are obtained using an analog circuit tester.

EC-41
 TROUBLE DIAGNOSIS

Service tool
DESCRIPTION
Service tool executes the following functions using the combination
of ECM data reception, instructions, and transmission from the VCM
via the communication line.
Diagnosis test mode Description

WORK SUPPORT • Reduces the preparation work necessary for inspecting.

• Displays input/output signal data related to the work.
• Allows setting control target values of idle speed or ignition timing.
• Allows performing "Idle Air Volume Learning".
SELF-DIAGNOSTIC RESULTS • Displays names of suspect circuits stored in ECM.
• Erases DTCs recorded in memory. (DTC: Diagnostic Trouble Cord)
DATA MONITOR • Provides useful data along with self-diagnosis results to determine the main cause.
• Displays input/output data of ECM in real time.
• Records and stores data.
• Detects malfunctions in real-time.
ACTIVE TEST • Can be used to determine and identify the primary sources of malfunctions based on self-
diagnosis results and data from DATA MONITOR.
• Each actuator is activated after receiving a drive signal.

OPERATION PROCEDURE
1. Turn ignition switch OFF.
2. Connect Service tool to VCM connector.
3. Turn ignition switch ON.
4. Touch "START".
5. Touch "ENGINE".
6. Perform the necessary trouble diagnosis mode.
Refer to "Service tool Operation Manual" for further information.

WORK SUPPORT
Service tool assists with idle adjustment work. With Service tool, it
sends an operation command to ECM, and adjustment control is
performed accordingly. However, inspector performs actual
adjustment work.

Display Item List

Work support item Description

FUEL PRESSURE RELEASE Shuts down the fuel pump and stops the engine. (While cranking, pressure in the fuel piping can be
released.)
IDLE AIR VOL LEARN Learns the minimum idle air flow amount required for idle speed control when predetermined conditions
are specified following replacement of electric throttle control actuator and ECM.
SELF-LEARNING CONT Clears air-fuel ratio feedback control correction coefficient.

EC-42
 TROUBLE DIAGNOSIS

Service tool (Cont’d)

SELF-DIAGNOSTIC RESULTS
When a malfunction occurs in ECM input/output signal circuit, the
malfunctioning circuit is recorded and displayed. Also, the
malfunction item that is occurred is displayed.

Display sample [Example: When there is a malfunction in mass air

flow sensor]
Display DTC and the malfunction item in the alarm monitor screen.

ECM0077

Display Item List

Engine
Diagnosis item Malfunction Return Condition Display Warning Trip
lamp

NO DTC • No malfunction is detected in any of the circuits. — — —

Mass air flow sensor (MAFS) • When engine is stopped (ignition switch ON) and mass air Air flow meter fault — —
flow sensor output voltage has been 4.9V or more for [E21]
predetermined period.
• When engine is running and mass air flow sensor output
voltage has been 0.5V or less for predetermined period.
• When air flow meter output voltage remains approximately
1V for a predetermined time while engine is running.
Engine coolant temperature • Engine coolant temperature sensor output voltage has Water temp sensor — 2
sensor (ECTS) (CIRCUIT) been approximately 4.8V or more (open) or less than fault [E22]
0.06V (short) for predetermined period
Throttle position sensor signal • Sensor power supply voltage has a malfunction. Throttle sensor fault ON* 1
circuit • Throttle position sensor signal circuit is open or shorted. [E23]
• A malfunction occurs in relation between throttle position
sensors 1 and 2.
• When the fully-closed position learning value was
unusually small or was not learning.
Acceleration sensor signal circuit • Accelerator pedal position sensor signal circuit is open or Accel sensor fault — 1
shorted. [E24]
• A malfunction occurs in relation between accelerator
pedal position sensors 1 and 2.
Heated oxygen sensor (circuit) • Heated oxygen sensor signal circuit is open. O2 sensor fault — 2
[E25]
Heated oxygen sensor (high • Heated oxygen sensor output voltage is higher than O2 sensor fault — 2
voltage) normal (2V or more). [E25]

EC-43
 TROUBLE DIAGNOSIS

Service tool (Cont’d)

Engine
Diagnosis item Malfunction Return Condition Display Warning Trip
lamp

Crankshaft position sensor • The crankshaft position sensor (POS) signal is not POS sensor fault ON 2
(POS) signal circuit detected for a predetermined time at the engine start or [E27]
during engine running (during camshaft position sensor
(PHASE) signal input).
• A crankshaft position sensor (POS) signal irregular
waveform is detected for a predetermined time during
engine running (during camshaft position sensor (PHASE)
signal input).
Camshaft position sensor • At start-up, no camshaft position sensor (PHASE) signal Phase sensor fault ON 2
(PHASE) signal circuit has been detected for more than a predetermined period. [E28]
• The camshaft position sensor (PHASE) signal is not
detected for a predetermined time during engine running
(during crankshaft position sensor (POS) signal input).
• A camshaft position sensor (PHASE) signal irregular
waveform is detected for a predetermined time during
engine running (during crankshaft position sensor (POS)
signal input).
Engine control module • CPU system or circuits in ECM have a malfunction. CCS C/U system ON* 1 or 2
fault [E30] (Note)
ECM power supply circuit • Power is not supplied to ECM for some time. ECM BACKUP/ ON 2
CIRC [P1065]
Electric throttle control actuator • Because of mechanical malfunction of electric throttle Throttle control fault — 1
control actuator, electric throttle control actuator does not [E31]
operate normally.
Electric throttle control function • When a malfunction occurred due to the correlation Throttle control fault — 1
between the target throttle position and the actual throttle [E31]
position.
• Over current flows into throttle motor control circuit.
Throttle control motor relay • When throttle control motor relay has been locked ON or Throttle control fault — Locked
circuit OFF. [E31] ON: 1
Locked
OFF: 2
Overheat (STEP1) • Coolant temperature sensor output voltage has been Overheat (STEP1) — 1
approximately 0.35V or lower for a predetermined period [E32]
of time. (With the coolant temperature sensor normal)
Ignition signal • Ignition signal has not been continuously generated while Ignition system fault — 1
the engine is running. [E34]
Brake switch • Brake switch signal circuit is open or shorted. Stop lamp SW fault — 2
[E41]
CAN communication system • Malfunction occurs in CAN communication transmit/ Communication — 1
receive data or in ECM, and data transmission/reception fault ECM [E04]
cannot be confirmed.
• CAN communication data is transmitted/received for
predetermined period.
LPG injector control signal circuit • LPG injector control signal circuit is open or shorted. F/INJ disconn [E35] — 1
LPG vaporizer fuel pressure • LPG fuel pressure in vaporizer is excessively high. LPG result signal — 1
fault [E38]
Lifting up switch signal circuit • When lifting up switch has been locked ON or OFF. Mast height SW — 2
fault [E39]

Note: Number of trips varies depending on diagnosis content.

CAUTION:
Some DTC specified above may detect a malfunction related in
vehicle side self-diagnosis when the DTC detects some
malfunction. Check self-diagnosis except engine at this time.

EC-44
TROUBLE DIAGNOSIS

Service tool (Cont’d)

Trip 1: If a malfunction is detected by self-diagnosis between the
time ignition switch is turned ON (engine is running) and then turned
OFF (this is defined as "trip"), Engine Warning lamp is lit. The
corresponding DTC is recorded immediately after detection.
Trip 2: When a malfunction is detected by self-diagnosis for the first
time in the first trip, a tentative DTC is recorded. If the same
malfunction is detected again by self-diagnosis in the next trip
(second trip), Engine Warning lamp is lit and the corresponding final
DTC is recorded.

Service tool self-diagnostic results timing

• For items of trip 1, timing "0" is displayed immediately after
detection of a malfunction.
• For items of trip 2, when a malfunction is detected for the first
time (trip 1), timing "1t" is displayed. When a malfunction is
detected again in the next trip (trip 2), it is displayed as "0".
Accumulative counting is performed at the end of warming-up
operation,

Conditions to turn off Engine Warning lamp

• The Engine Warning lamp, marked with *, is turned off when
ignition switch is turned ON (engine starts) again after normal
state is resumed.
• For other self-diagnostic items, self-diagnostic results shall be
erased by turning ignition switch to OFF after normal operation
is resumed.

DATA MONITOR
• Allows determination and identification of the possible source of
a malfunction based on self-diagnosis test results.
• Displays ECM input/output signal data in real time.
• Records the data before and after engine stalls, falters or
refuses to start intentionally.

EC-45
 TROUBLE DIAGNOSIS

Service tool (Cont’d)

Display Item List
Monitor item Unit Description

Eng.rev rpm Engine speed computed from crankshaft angle sensor signal
Air flow meter mV Mass air flow sensor output voltage
Cly air ratio GAS % Average of cycles for air-fuel ratio feedback correction coefficient
Cly air ratio LPG
Eng.temp °C Value converted into temperature from the output voltage of the engine coolant temperature
sensor.
O2 sensor volt mV Output voltage of heated oxygen sensor
O2 sensor rich ON/OFF Air-fuel ratio is given as heated oxygen sensor output signal during air-fuel ratio feedback control.
ON: Heated oxygen sensor output is high. Controlling to lower the value for leaner ratio.
OFF: Heated oxygen sensor output is low. Controlling to raise the value for richer ratio.
Battery voltage mV ECM battery voltage
Accelerator % Value converted from the output voltage of accelerator pedal position sensor into accelerator
position
Throttle % Value converted from the output voltage of throttle position sensor into throttle position
Air temp sensor °C Value converted from the output power supply of intake air temperature sensor into intake air
temperature
Stater SW ON/OFF ON/OFF status as judged by each input signal
Idle SW
Air conditioner SW
Neutral SW
Mast high SW 1,2
Electric load SW
Chg fuel SW 1,2
Inching SW
Foot brake SW
Fuel jet pls GAS µs Value calculated by ECM
Fuel jet pls LPG
Spark timing deg
Fuel pump relay ON/OFF Status of each control as calculated by ECM.
Throttle relay
LPG relay
O2 sensor heater
TAS completion ON/OFF State of "Idle Air Volume Learning".
Ratio date clr comp ON/OFF Status of each control as calculated by ECM.
TAS factory run
TAS general run
Spark correct run
Ratio correct run
Power balance run
Pressure clr run
Self chk clr comp
All shut update exp
Connect CONSULT-II
Cly air ratio GAS % Value converted from the output voltage of mass air flow sensor into filling efficiency.
Cly air ratio LPG
Fuel control GASOLINE/ Fuel changing switch connecting condition
LPG/NEUTRAL
LPG pres sensor kg/cm2 Value converted into pressure from the output voltage of LPG fuel pressure sensor.

EC-46
 TROUBLE DIAGNOSIS

Service tool (Cont’d)

ACTIVE TEST
Use this mode to determine and identify the details of a malfunction,
based on self-diagnosis test results and data obtained from DATA
MONITOR mode. Service tool, instead of the ECM on the vehicle,
sends a drive signal to actuators to check their operation.

Display Item List

Active test item Description

FUEL PRESSURE • Can increase or decrease the amount of fuel injection ( ±25%).
RELEASE
• Can reproduce conditions resulting from air-fuel ratio related malfunctions (e.g. hesitation, poor acceleration,
poor racing, etc.) and can help solve these malfunctions by pinpointing the causes.
IGNITION TIMING • Allows setting a correction coefficient for retarding (-10 - 0°)
POWER BALANCE • Stops operation of specified injector. Also, displays the condition at that time.
• Mainly used to inspect for misfiring cylinders.

Self-Diagnosis Function (Without Service

tool)
DESCRIPTION
• In self-diagnosis, when any of the critical sensors or actuator
and exhaust gas control systems necessary for ECM control
return a malfunction and self-diagnosis detection conditions are
satisfied, a DTC corresponding to the suspect system is stored
in ECM for easier trouble diagnosis. Self-diagnostic results can
be displayed with either Service tool or Engine Warning lamp in
the (combination) meter. Engine Warning lamp indication is
explained here.
• The trouble diagnosis mode has two types: mode 1 and mode
2. Mode 1 is normal mode and mode 2 is self-diagnosis or
heated oxygen sensor monitor function.

OPERATION PROCEDURE
• Refer to the following for how to activate self-diagnosis mode or
erase heated oxygen sensor monitor and self-diagnostic results.

CAUTION:
When a malfunction occurs in accelerator pedal position
sensors, self-diagnosis (without Service toolService tool)
cannot be activated. Thus, use Service tool to perform self-
diagnosis, and repair malfunctioning part.

EC-47
TROUBLE DIAGNOSIS

Self-Diagnosis Function (Without Service

tool) (Cont’d)

ECM0078

DIAGNOSTIC TEST MODE 1 - BULB CHECK

• Engine Warning lamp should turn on when the ignition switch is
turned ON (engine stopped), and turn off after the engine starts.

DIAGNOSTIC TEST MODE 1 - MALFUNCTION WARNING

• When a malfunction is detected by self-diagnosis, the system
goes into the malfunction warning mode and warns the driver by
blinking the Engine Warning lamp in the (combination) meter.
• There are two types of warning indications: items for which
warning is given by Engine Warning lamp indication for the first
trip and those for which warning is given by Engine Warning
lamp indication for the second trip. For the latter, the Engine
Warning lamp will not light up for the first trip.

DIAGNOSTIC TEST MODE II - SELF-DIAGNOSTIC RESULTS

• In this mode, the Engine Warning lamp blinks (indicating the
DTC) to identify the system that returned a malfunction.
• If no malfunction is detected, the code "0000" is displayed.

EC-48
 TROUBLE DIAGNOSIS

Self-Diagnosis Function (Without Service

tool) (Cont’d)
Display Item List
DTC ENGINE
(code Diagnosis item Malfunction Return Condition Warning Trip
number) lamp

0000 NO DTC • No malfunction is detected in any of the circuits. — —

E23 Throttle position sensor • Sensor power supply voltage has a malfunction. ON* —
signal circuit • Throttle position sensor signal circuit is open or shorted.
• A malfunction occurs in relation between throttle position sensors 1
and 2.
• When the fully-closed position learning value was unusually small or
was not learning.
E27 Crankshaft position sensor • The crankshaft position sensor (POS) signal is not detected for a ON 2
(POS) signal circuit predetermined time at the engine start or during engine running
(during camshaft position sensor (PHASE) signal input).
• A crankshaft position sensor (POS) signal irregular waveform is
detected for a predetermined time during engine running (during
camshaft position sensor (PHASE) signal input).
E28 Camshaft position sensor • At start-up, no camshaft position sensor (PHASE) signal has been ON 2
(PHASE) signal circuit detected for more than a predetermined period.
• The camshaft position sensor (PHASE) signal is not detected for a
predetermined time during engine running (during crankshaft
position sensor (POS) signal input).
• A camshaft position sensor (PHASE) signal irregular waveform is
detected for a predetermined time during engine running (during
crankshaft position sensor (POS) signal input).
0500 Vehicle speed sensor • Vehicle sensor signal has not been input under some condition for a ON 2
predetermined time during driving after warming up.
E30 Engine control module • CPU system or circuits in ECM have a malfunction. ON* 1 or 2 (Note)
E33 Engine over temperature • Coolant temperature sensor output voltage has been approximately ON 1
(Overheat) 0.35V or lower for a predetermined period of time. (With the coolant
temperature sensor normal)

Note: Number of trips varies depending on diagnosis content.

CAUTION:
Some DTC specified above may detect a malfunction related in
vehicle side self-diagnosis when the DTC detects some
malfunction. Check self-diagnosis except engine at this time.
Trip 1: If a malfunction is detected by self-diagnosis between the
time ignition switch is turned ON (engine is running) and then turned
OFF (this is defined as "trip"), Engine Warning lamp is lit. The
corresponding DTC is recorded immediately after detection.
Trip 2: When a malfunction is detected by self-diagnosis for the first
time in the first trip, a tentative DTC is recorded. If the same
malfunction is detected again by self-diagnosis in the next trip
(second trip), Engine Warning lamp is lit and the corresponding final
DTC is recorded. Even when 1st trip DTC is being memorized, the
appropriate malfunction code is displayed as self-diagnostic results
by Engine Warning lamp.

EC-49
 TROUBLE DIAGNOSIS

Self-diagnosis function (without Service

tool) (Cont’d)
Conditions to turn off Engine Warning lamp
• The Engine Warning lamp, marked with *, is turned off when
ignition switch is turned ON (engine starts) again after normal
state is resumed.
• For other self-diagnostic items, self-diagnostic results shall be
erased by turning ignition switch to OFF after normal operation
is resumed.

DIAGNOSTIC TEST MODE II - HEATED OXYGEN SENSOR

MONITOR
• In this mode, status of air-fuel ratio is displayed by blinking of
Engine Warning lamp.
• Make sure that Engine Warning lamp blinks at least 5 times
within 10 seconds after warming up engine and keeping engine
speed at approximately 2,000 rpm.
NOTE:
• Although air-fuel ratio feedback control is active at idle, increase
engine speed and check.
• During air-fuel ratio feedback control
ECM0080 Heated oxygen sensor output is large (rich).: OFF
Heated oxygen sensor output is small (lean).: ON
• Air-fuel ratio feedback control is stopped: OFF
• Air-fuel ratio feedback control is clamped: State immediately
before clamping is maintained.

Service tool Reference Value in Data Monitor

• Values in the table are reference values.
• Values in the table are values detected in ECM or input/output
values sent from ECM. Thus, they may differ from actual part
values. [Example: ignition timing checked using timing light and
display on "IGN TIMING" screen in "DATA MONITOR" mode
could be different. This happens because values on "IGN
TIMING" screen is calculated by ECM using input signal from
various sensors. They are crankshaft position sensor (POS)
and other ignition timing related sensors.]
Monitor item Measurement condition Reference value

Eng. Rev • Tachometer: Connected Almost in accordance

• Start engine, and compare with the value displayed by tachometer.
Air flow meter • After engine warming up At Idle Approx. 1.3V
• A/C SW: OFF
At approx. 2,000 rpm Approx. 1.6V
• Selector lever: neutral or N
• No load
Cly air ratio GAS • After engine warming up At Idle Approx. 90 - 110%
Cly air ratio LPG
Eng. temp • After engine warming up Approx. 80°C (176°F) or more
O2 sensor volt • After engine warming up At Idle Changes between approx.
0.1 - 0.4V⇔0.6 - 0.9V
Maintain at approx. 2,000 rpm Changes between approx.
0.1 - 0.4V⇔0.6 - 0.9V
O2 sensor rich • After engine warming up At Idle Switches slowly between
LEAN⇔RICH.
Maintain at approx. 2,000 rpm Switches between LEAN⇔RICH at
least 5 times for 10 seconds.

EC-50
 TROUBLE DIAGNOSIS

Service tool Reference Value in Data Monitor

(Cont’d)
Monitor item Measurement condition Reference value

Battery voltage • Ignition switch: ON (with engine Approx. 11 - 14V

stopped)
Accelerator • After engine warming up At Idle Approx. 0.6 - 0.65V
Approx. 2,000 rpm Approx. 0.75 - 0.8V
Ignition switch ON with accelerator pedal Approx. 4.1 - 4.3V
depressed (With engine stopped)
Throttle • After engine warming up At Idle Approx. 0.5 - 0.55V
Approx. 2,000 rpm Approx. 0.65 - 0.7V
Ignition switch ON with accelerator pedal Approx. 0.7 - 0.75V
depressed (With engine stopped)
Air temp sensor • After engine warming up Values according to intake air
temperature
Starter SW • Ignition switch: ON → START → ON OFF → ON → OFF
Idle SW • After engine warming up Accelerator pedal is fully depressed ON
• Ignition switch: ON (with engine
Accelerator pedal is released OFF
stopped)
Air conditioner SW • After engine warmed up (at idle) A/C SW: OFF OFF
A/C switch: ON (compressor is ON
operating)
Neutral SW • Ignition switch: ON Neutral, or N ON
Other than above OFF
Electric load SW • Ignition switch: ON Headlamp switch: ON ON
Above switch: OFF OFF
Foot brake SW • Ignition switch: ON Brake pedal depressed ON
Brake pedal released OFF
Fuel jet pls GAS • After engine warming up At Idle Approx. 2 - 4 msec
Fuel jet pls LPG • Selector lever: neutral or N At approx. 2,000 rpm
• No load
Spark timing • After engine warming up At Idle Approx. 15°BTDC
• Selector lever: N
At approx. 2,000 rpm Approx. 30 - 40°BTDC
• No load
Fuel pump relay • For 1 second after ignition switch is ON ON
• While engine is running and cranking
• Other than above OFF
Throttle relay • Ignition switch: ON → OFF ON → OFF
O2 sensor heater • After engine warmed up (at idle) ON
TAS completion • After engine warmed up (at idle) Learning completed ON
• All electrical load switches: OFF
Learning not yet completed OFF
• Selector lever: neutral or N
• Throttle valve closed position learning
completed
Mast high SW1 • Engine running Fork is approximately 50 cm (19.7 in) on ON
Mast high SW2 • Lifting up operation this side of maximum lifting up stroke
end.
Fork is down from the above position. OFF
Chg fuel SW1 • Ignition switch: ON Fuel changing switch: LPG ON
Fuel changing switch: Gasoline or neutral OFF
Chg fuel SW2 • Ignition switch: ON Fuel changing switch: Gasoline ON
Fuel changing switch: LPG or neutral OFF
Inching SW • Ignition switch: ON Inching pedal depressed ON
Inching pedal released OFF

EC-51
 TROUBLE DIAGNOSIS

Service tool Reference Value in Data Monitor

(Cont’d)
Monitor item Measurement condition Reference value

LPG relay • While engine is running and cranking ON

• Other than above OFF
Cyl air ratio GAS • After engine warming up At Idle Approx. 30%
• Selector lever: neutral or N
At approx. 2,000 rpm Approx. 20%
• While engine is running on gasoline
• While engine is running on LPG. 0%
Cyl air ratio LPG • After engine warming up At Idle Approx. 30%
• Selector lever: neutral or N
At approx. 2,000 rpm Approx. 20%
• While engine is running on LPG.
• While engine is running on LPG. 0%
LPG pres sensor • Ignition switch: ON Approx. 29 kPa (0.29 bar, 0.3
kg/cm2, 4 psi)
Ratio data clr comp • Perform air-fuel ratio learning clear in Complete ON
active test.
Not yet complete OFF
TAS factory run • Perform idle air volume learning (plant) Active ON
in active test Inactive OFF
TAS general run Perform idle air volume learning (active) in Active ON
active test Inactive OFF
Spark correct run • Perform target idle timing adjustment in Active ON
active test
Inactive OFF
Ratio correct run • Perform air-fuel ratio correction in Active ON
active test
Inactive OFF
Power balance run • Perform power balance in active test Active ON
Inactive OFF
Pressure clr run • Perform fuel pressure release in active Active ON
test
Inactive OFF
Self chk clr comp • Perform self-diagnostic results clear in Active ON
active test Inactive OFF
All shut update exp • Ignition switch: ON Closed position learning completed ON
Closed position leaning not yet OFF
completed
Tas completion • Perform idle air volume learning in Complete ON
active test Not yet complete OFF
Connect consult2 • Ignition switch: ON When connected to Service tool ON
When not connected to Service tool OFF

EC-52
 TROUBLE DIAGNOSIS

Fail-Safe Function
When any of the critical sensors or systems sends a malfunction
message, the fail-safe function estimates the driving conditions with
other input signals and selects safer conditions for engine (vehicle)
control, based on data previously stored in ECM.
Engine
Related sensors Malfunction condition Fail-safe Warning
lamp

Mass air flow sensor Same as self-diagnosis • Selects fuel injection pulse width depending on engine speed and ON
malfunction detection throttle position so the vehicle can be driven. However, fuel injection
conditions. will be inhibited (fuel cut off) when engine speed exceeds
approximately 2,400 rpm.
• Idle speed is 800 rpm.
Engine coolant • Uses the estimated engine coolant temperature (varies with elapsed ON
temperature sensor time after start) to perform controls so the vehicle can be driven.
Accelerator pedal position • Fuel injection will be inhibited when 1 circuit is opened. Release ON
sensor valve mechanically until it can drive at low speed when disconnecting
connector.
Throttle position sensor • Fixes output to a preset value so the vehicle can be driven. However, ON
fuel injection will be inhibited (fuel cut off) when engine speed
exceeds approximately 2,500 rpm.
Malfunction indicator lamp • Fuel injector will be inhibited at approximately 2,500 rpm to prevent —
Engine Warning lamp malfunction if exhaust performance and
driving performance malfunctions are occurring.

EC-53
 POWER SUPPLY AND GROUND SYSTEM

POWER SUPPLY AND ECM Input/Output Signal Specifications

GROUND SYSTEM Measure voltage between terminals shown below and ground using
a circuit tester.
Terminal signal Signal name Measurement condition Measured value

111 Self shut-off For approximately 10 seconds with ignition switch Approx. 1V
ON and after ignition switch OFF
Approximately 10 seconds or more after ignition Battery voltage
switch OFF
109 Ignition switch Ignition switch ON
119 Power supply for ECM
120
121 Power supply (backup) Always
115 Ground Approx. 0V
116
1

Circuit Diagram

ECM0081

EC-54
 CRANKSHAFT POSITION SENSOR (POS) SYSTEM

CRANKSHAFT POSITION ECM Input/Output Signal Specifications

SENSOR (POS) SYS- Check waveform between terminals shown below and ground using
an oscilloscope.
TEM
Terminal Signal name At cranking At idle after warming up At approx. 2,000 rpm

13 Crankshaft position Approx. 2.6V Approx. 3V Approx. 3V

sensor (POS)

ECM0082 ECM0083 ECM0084

Numerical values (reference values) are obtained using an analog

circuit tester.

Circuit Diagram

ECM0085

Component Parts Inspection

Crankshaft position sensor (POS)
Check resistance between terminals using an analog circuit tester.
At room temperature
(+) - (-) Resistance
3-1 : Not 0 Ω nor ∞ Ω
2-1 : Not 0 Ω nor ∞ Ω
3-2 : Not 0 Ω nor ∞ Ω

CAUTION:
Measurement values will vary depending on the measurement
range of circuit tester. Note that the higher the range is, the
larger the resistance is.
ECM0086

EC-55
 CAMSHAFT POSITION SENSOR (PHASE) SYSTEM

CAMSHAFT POSITION ECM Input/Output Signal Specifications

SENSOR (PHASE) SYS- Check waveform between terminals shown below and ground using
an oscilloscope.
TEM
Terminal Signal name At cranking At idle after warming up At approx. 2,000 rpm

14 Camshaft position Approx. 0.15V Fluctuates between approx. 1.5 - 2V. Approx. 2V
sensor (PHASE)

ECM0087 ECM0088 ECM0089

Numerical values (reference values) are obtained using an analog

circuit tester.

Circuit Diagram

ECM0090

Component Parts Inspection

Camshaft position sensor (PHASE)
Check resistance between terminals using an analog circuit tester.
At room temperature
(+) - (-) Resistance
3-1 : Not 0 Ω nor ∞ Ω
2-1 : Not 0 Ω nor ∞ Ω
3-2 : Not 0 Ω nor ∞ Ω

CAUTION:
Measurement values will vary depending on the measurement
range of circuit tester. Note that the higher the range is, the
ECM0091
larger the resistance is.

EC-56
 MASS AIR FLOW SENSOR SYSTEM

MASS AIR FLOW SENSOR SYSTEM Service tool Data Monitor Display
Monitor item At idle after warming up At approx. 2,000 rpm

Air flow meter Approx. 1.3V Approx. 1.6V

ECM Input/Output Signal Specifications

Measure voltage between terminals shown below and ground using
a circuit tester.
Terminal Signal name At cranking At idle after warming up At approx. 2,000 rpm

51 Mass air flow sensor Approx. 1.5V Approx. 1.3V Approx. 1.5V
67 Mass air flow sensor ground Approx. 0V

Circuit Diagram

ECM0092

Component Parts Inspection

Mass air flow sensor
1. Remove mass air flow sensor.
2. Turn ignition switch to ON. While blowing air into the mass air
flow sensor from the air cleaner case side, check output voltage
between terminal 3 and ground.
No air blowing: Approx. 1V
With air blowing: Approx. 1.3V
(The more the air is blown, the higher the voltage is.)

CAUTION:
If air is blown from the air duct side, the voltage becomes lower.
ECM0093

EC-57
 ENGINE COOLANT TEMPERATURE SENSOR SYSTEM

ENGINE COOLANT TEMPERA- Service tool Data Monitor Display

TURE SENSOR SYSTEM
Monitor item At idle after warming up At approx. 2,000 rpm

Eng. temp After warming up engine: Approx. 80°C or more

ECM Input/Output Signal Specifications

Measure voltage between terminals shown below and ground using
a circuit tester.
Terminal Signal name At Idle At approx. 2,000 rpm

73 Engine coolant Engine coolant temperature at approx.

temperature sensor signal 20°C (68°F): Approx. 3.5V
Engine coolant temperature at approx.
80°C (176°F): Approx. 1.2V

NOTE:
ECM0382 • If engine coolant temperature sensor has a malfunction, the
value of engine coolant temperature signal is changed along
with start-up time by fail-safe to enable normal operation.

Circuit Diagram

ECM0095

Component Parts Inspection

Engine coolant temperature sensor
Check resistance between terminals 1 and 2 on the engine coolant
temperature sensor.
Resistance
Coolant temperature at approx. 20°C (68°F): Approx.
2.5 k Ω
Coolant temperature at approx. 80°C (176°F): Approx.
0.3 k Ω

ECM0383

EC-58
 HEATED OXYGEN SENSOR SYSTEM

HEATED OXYGEN SENSOR SYSTEM Service tool Data Monitor Display

Monitor item At idle after warming up At approx. 2,000 rpm

O2 sensor volt Changes between approx. 0.1 - 0.4V⇔ approx. 0.6 - 0.9V
O2 sensor rich ON and OFF alternate slowly. ON and OFF alternate at least 5 times in 10 seconds.

ECM Input/Output Signal Specifications

Check waveform between terminals shown below and ground using
an oscilloscope.
Terminal Signal name At idle after warming up At approx. 2,000 rpm

35 Heated oxygen sensor Changes between approx. 0.1 - 0.4V⇔ approx. ←

0.6 - 0.9V

ECM0097 ECM0098

Numerical values (reference values) are obtained using an analog

circuit tester.

Circuit Diagram

ECM0099

EC-59
 THROTTLE POSITION SENSOR SYSTEM

THROTTLE POSITION SENSOR SYSTEM Service tool Data Monitor Display

Monitor item At idle after warming up At approx. 2,000 rpm

Throttle Approx. 0.5 - 0.55V Approx. 0.65 - 0.7V

ECM Input/Output Signal Specifications

Measure voltage between terminals shown below and ground using
a circuit tester.
Terminal Signal name At idle after warming up At approx. 2,000 rpm

66 Sensor ground (Throttle position sensor) Approx. 0V

47 Electric throttle control actuator open Approx. 5V
50 Throttle position sensor 1 Approx. 0.6V Approx. 0.7V
69 Throttle position sensor 2 Approx. 4.5V Approx. 4.4V

Circuit Diagram

ECM0100

Component Parts Inspection

THROTTLE POSITION SENSOR 1, 2 (ELECTRIC THROTTLE
CONTROL ACTUATOR ASSEMBLY)
Check voltage between ECM terminal 50, 69 and ground.
Refer to (EC-36), "ECM Input/Output Signal Specifications" for the
voltage.

CAUTION:
• Make sure that there is no moisture around connector
when removing and installing throttle position sensor con-
nector. If there are any water drops, completely wipe them
off.
• Do not apply voltage to throttle position sensor terminal.
• Perform "Throttle Valve Closed Position Learning" if dis-
ECM0101
connecting connector. Perform "Throttle Valve Closed
Position Learning and Idle Air Volume Learning" if replac-
ing electric throttle control actuator. (Refer to (EC-13),
"Throttle Valve Closed Position Learning and Idle Air Vol-
ume Learning".)
• Do not disassemble electric throttle control actuator.

EC-60
 ACCELERATOR PEDAL POSITION SENSOR SYSTEM

ACCELERATOR PEDAL POSITION SENSOR SYSTEM Service tool Data Monitor Display
Monitor item At idle after warming up At approx. 2,000 rpm

Accelerator Approx. 0.6 - 0.65V Approx. 0.75 - 0.8V

ECM Input/Output Signal Specifications

Measure voltage between terminals shown below and ground using
a circuit tester.
Terminal Signal name At Idle At approx. 2,000 rpm

90 Sensor power supply Approx. 5V

106 Accelerator pedal position sensor 1 Approx. 0.6V Approx. 0.65V
82 Sensor ground Approx. 0V
91 Accelerator pedal position sensor 2 power supply Approx. 2.5V
98 Accelerator pedal position sensor 2 Approx. 0.3V Approx. 0.35V
83 Accelerator pedal position sensor 2 ground Approx. 0V

NOTE:
• When the accelerator pedal is depressed slowly from the fully-
closed position, the voltage must increase in proportion to the
opening of the throttle. [Ignition switch ON (engine stopped)]
Ignition switch ON, engine stopped Ignition switch ON, engine stopped
Terminal Signal name
Accelerator pedal is fully depressed Accelerator pedal is fully released
106 Accelerator pedal position sensor 1 Approx. 0.6V Approx. 4.2V
98 Accelerator pedal position sensor 2 Approx. 0.3V Approx. 2V

Circuit Diagram

ECM0102

Component Parts Inspection

ACCELERATOR PEDAL POSITION SENSORS 1, 2 (ACCELERA-
TOR WORK UNIT)
Check voltage between ECM terminal 106, 98 and ground.
Refer to (EC-36), "ECM Input/Output Signal Specifications" for the
voltage.

CAUTION:
• Do not apply voltage to accelerator pedal position sensor
terminal.
• Do not disassemble accelerator work unit.

ECM0103

EC-61
 INTAKE AIR TEMPERATURE SENSOR

INTAKE AIR TEMPERATURE SENSOR Service tool Data Monitor Display

Monitor item At Idle At approx. 2,000 rpm

Air temp sensor Values according to intake air temperature

ECM Input/Output Signal Specifications

Measure voltage between terminals shown below and ground using
a circuit tester.
Terminal Signal name At Idle At approx. 2,000 rpm

34 Intake air temperature sensor signal Intake air temperature at 20°C (68°F): approx. 3.5V
Intake air temperature at 80°C (176°F): approx. 1.2V

Circuit Diagram

ECM0092

Component Parts Inspection

INTAKE AIR TEMPERATURE SENSOR (JOINED WITH MASS
AIR FLOW SENSOR)
Check resistance between intake air temperature sensor (mass air
flow sensor connector) terminals 3 and 5.
Resistance
Intake air temperature at approx. 20°C (68°F): Approx. 2.5
kΩ
Intake air temperature at approx. 80°C (176°F): Approx. 0.3
kΩ

ECM0384

EC-62
 PNP SWITCH SYSTEM

PNP SWITCH SYSTEM Service tool Data Monitor Display

Monitor item Neutral, or N position Other than the left

Neutral SW ON OFF

ECM Input/Output Signal Specifications

Measure voltage between terminals shown below and ground using
a circuit tester.
Terminal Signal name Neutral, or N position Other than the left

102 PNP switch Approx. 0V Battery voltage (A/T models)

Approx. 4.8V (M/T models)

Circuit Diagram

ECM0106

EC-63
 STOP LAMP SWITCH SYSTEM

STOP LAMP SWITCH SYSTEM Service tool Data Monitor Display

Monitor item Brake pedal released Brake pedal depressed

Foot brake SW OFF ON

ECM Input/Output Signal Specifications

Measure voltage between terminals shown below and ground using
a circuit tester.
Terminal Signal name Brake pedal released Brake pedal depressed

101 Brake switch Approx. 0V Battery voltage

Circuit Diagram

ECM0107

Component Parts Inspection

Stop lamp switch
Check continuity between stop lamp switch terminals 1 and 2.
Brake pedal released: Continuity should not exist.
Brake pedal depressed: Continuity should exist.

ECM0108

EC-64
 ELECTRIC LOAD SWITCH SYSTEM

ELECTRIC LOAD SWITCH SYSTEM Service tool Data Monitor Display

Monitor item Headlamp OFF Headlamp ON

Electric load SW OFF ON

ECM Input/Output Signal Specifications

Measure voltage between terminals shown below and ground using
a circuit tester.
Terminal Signal name Headlamp switch OFF Headlamp switch ON

84 Headlamp switch Approx. 0V Battery voltage

Circuit Diagram

ECM0109

EC-65
 CAN COMMUNICATION SYSTEM

CAN COMMUNICATION SYSTEM ECM Input/Output Signal Specifications

Check waveform between terminals shown below and ground using
an oscilloscope.
Terminal Headlamp switch OFF Headlamp switch ON

94 CAN communication line H Approx. 2.4V (Varies depending on communication status.)

ECM0110

86 CAN communication line L Approx. 2.2V (Varies depending on communication status.)

ECM0111

Numerical values (reference values) are obtained using an analog

circuit tester.

Circuit Diagram

ECM0112

EC-66
 IGNITION SYSTEM

IGNITION SYSTEM Service tool Data Monitor Display

Monitor item At idle after warming up At approx. 2,000 rpm

Spark timing Approx. 0 deg

ECM Input/Output Signal Specifications

Check waveform between terminals shown below and ground using
an oscilloscope.
Terminal Signal name At cranking At idle after warming up At approx. 2,000 rpm

61 Ignition signal (power Approx. 0.2V Approx. 0.1V Approx. 0.1V

62 transmission drive signal)
80
81

ECM0113 ECM0114 ECM0115

Numerical values (reference values) are obtained using an analog

circuit tester.

Circuit Diagram

ECM0116

Component Parts Inspection

Spark plug
• Check electrode for dirt, damage, and wear and insulator for
damage.
• Replace spark plug if necessary.

CAUTION:
• Check terminals for looseness.
• Check insulator for cracks or damage.
• Check for contamination by oil, water, and dust.
• Make sure that the spark plug gap is normal, using a feeler
gauge.
Spark plug gap: 0.8 - 0.9 mm (0.031 - 0.035 in)
ECM0117

EC-67
 IGNITION SYSTEM

Ignition coil
Check the resistance between terminals of the power transistor by
applying and exchanging (+ and -) the inspection rods of an analog
circuit tester.
(+) - (-) Resistance (at room temperature)
1-2 : Not 0 Ω nor ∞ Ω
2-1 : Not 0 Ω nor ∞ Ω
3-1 : Except 0 Ω
1-3 : Except 0 Ω
3-2 : Except 0 Ω
2-3 : Except 0 Ω
ECM0118
CAUTION:
Do not use a digital circuit tester because the standard is
different.

EC-68
 FUEL INJECTOR SYSTEM

FUEL INJECTOR SYSTEM Service tool Data Monitor Display

Monitor item At idle after warming up At approx. 2,000 rpm

Fuel jet pls GAS Approx. 2 µs

ECM Input/Output Signal Specifications

Check waveform between terminals shown below and ground using
an oscilloscope.
Terminal Signal name At cranking At idle after warming up At approx. 2,000 rpm

22 Injector drive signal Approx. 10.5V Battery voltage Relatively lower than battery voltage
23
41
42

ECM0119 ECM0120 ECM0121

Numerical values (reference values) are obtained using an analog

circuit tester.

Circuit Diagram

ECM0122

Component Parts Inspection

Injector
• Check resistance between each cylinder injector terminals 1
and 2.
Standard resistance (all cylinders): Approx. 14.5 Ω
(at room temperature)

ECM0123

EC-69
 FUEL PUMP SYSTEM

FUEL PUMP SYSTEM Service tool Data Monitor Display

Monitor item Fuel pump is not activated Fuel pump is operated

Fuel pump relay OFF ON

ECM Input/Output Signal Specifications

Measure voltage between terminals shown below and ground using
a circuit tester.
Terminal Signal name For approx. 1 second after ignition switch is turned ON At cranking, engine running

113 Gasoline F/P relay Approx. 1V (After approx. 1 second: Battery voltage) Approx. 1V

Circuit Diagram

ECM0124

Component Parts Inspection

Fuel pump
Check resistance between terminals 3 and 6.
Resistance: Approx. 1 Ω (at room temperature)

EC-70
 THROTTLE CONTROL MOTOR SYSTEM

THROTTLE CONTROL ECM Input/Output Signal Specifications

MOTOR SYSTEM Measure voltage between terminals shown below and ground using
a circuit tester.
Terminal Signal name At idle after warming up At approx. 2,000 rpm

5 Throttle control motor 1 (Open) Approx. 0.1 - 0.15V

4 Throttle control motor 2 (Close) Approx. 2 - 2.5V

Circuit Diagram

ECM0100

Component Parts Inspection

Electric throttle control motor (Electric throttle control actuator
assembly)
Check resistance between electric throttle control motor (throttle
position sensor connector) terminals 3 and 6.
Resistance: Approx. 1 -15 Ω [at 25°C (77°F)]

CAUTION:
• Make sure that there is no moisture around connector
when removing and installing throttle position sensor con-
nector. Completely wipe off water drops if there are any.
• Do not apply voltage to electric throttle control motor termi-
nal.
• Perform "Throttle Valve Closed Position Learning" if dis-
ECM0126
connecting connector. Perform "Throttle Valve Closed
Position Learning and Idle Air Volume Learning" if replac-
ing electric throttle control actuator. (Refer to (EC-13),
"Throttle Valve Closed Position Learning and Idle Air Vol-
ume Learning".)
• Do not disassemble electric throttle control actuator.

EC-71
 HEATED OXYGEN SENSOR HEATER SYSTEM

HEATED OXYGEN SENSOR HEATER SYSTEM Service tool Data Monitor Display
Monitor item At idle after warming up

Oxygen sensor heater ON

ECM Input/Output Signal Specifications

Measure voltage between terminals shown below and ground using
a circuit tester.
Terminal Signal name At idle after warming up Approx. 3600 rpm or more

24 Heated oxygen sensor heater open signal Approx. 0.3V Battery voltage

Circuit Diagram

ECM0099

Component Parts Inspection

Heated oxygen sensor 1 Heater
Check resistance between heated oxygen sensor terminals 2 and 3.
Resistance: Approx. 3.3 - 3.5 Ω

ECM0128

EC-72
 PCV GAS RECIRCULATION DEVICE

PCV GAS RECIRCULATION DEVICE System Diagram

ECM0143

Component Parts Inspection

PCV valve
1. At idle, remove PCV valve together with hoses from rocker
cover.
2. Check if hissing sound is heard from the air passage when PCV
valve is operating normally.

ECM0144

3. Check air flow through the PCV valve and sucking air to/from
the INT end.
Blowing air: No air flow
Sucking air: Air flow exists

ECM0145

EC-73
 FUEL CUT FUNCTION

FUEL CUT FUNCTION Inspection Procedure

With Service tool
1. Check "INJ PULSE GAS" (gasoline) or "INJ PULSE LPG"
(LPG) in Input/Output monitor, and increase the engine speed
to approximately 2,500 rpm after warming up engine.
2. Make sure that "INJ PULSE GAS" (gasoline) or "INJ PULSE
LPG" (LPG) instantly drops when accelerator pedal is released.

ECM0146
Without Service tool
1. Warm up the engine sufficiently.
2. Disconnect harness connector of the injector and connect a test
lamp.
3. Release the accelerator pedal at the engine speed of
approximately 2,500 rpm or more, and confirm test lamp goes
off for a moment.

ECM0147

EC-74
 REMOVAL AND INSTALLATION OF ECM COMPONENTS

REMOVAL AND INSTALLATION OF ECM COMPONENTS Removal and Installation of ECM

1. Disconnect ECM connector.
2. Remove ECM together with ECM bracket.
3. Remove ECM bracket.
4. Install in the reverse order of removal.

CAUTION:
Perform "Throttle Valve Closed Position Learning and Idle Air
Volume Learning" after installation if replacing ECM. (Refer to
(EC-12), "Throttle Valve Closed Position Learning and Idle Air
Volume Learning".)
ECM0148
Removal and Installation of Crankshaft
Position Sensor (POS)
Removal
1. Remove fan.
2. Remove harness connector.
3. Remove crankshaft position sensor (POS).

Installation
NOTE:
• Make sure that there is no foreign material on sensor flange, O-
rings, and cylinder block.
• Keep away from magnetized objects.

ECM0385 • Make sure that the sensor is inserted securely into front cover
before tightening bolts.

Removal and Installation of Camshaft

Position Sensor (PHASE)
Removal
1. Remove fan.
2. Remove harness connector.
3. Remove camshaft position sensor (PHASE).

Installation
NOTE:
• Make sure that there is no foreign material on sensor flange, O-
rings, and chain housing.
• Keep away from magnetized objects.
ECM0386 • Make sure that the sensor is inserted securely into cylinder
head front cover before tightening bolts.

EC-75
REMOVAL AND INSTALLATION OF ECM COMPONENTS

Removal and Installation of Mass Air Flow

Sensor
1. Remove harness connector.
2. Remove mass air flow sensor assembly from air horn.

ECM0151

Removal and Installation of Engine Coolant

Temperature Sensor.
1. Disconnect radiator drain plug, and drain coolant.

CAUTION:
Make sure to drain when the coolant temperature is cold.
2. Remove harness connector.
3. Remove coolant temperature sensor using a socket specially
designed for removing and installing coolant temperature
sensors [commercially available: Thermosensor Socket
manufactured by KTC (part No.: B20T-19)] and similar parts.

ECM0387
Removal and Installation of Heated Oxygen
Sensor (with Heated Oxygen Sensor Heater)
1. Remove harness connector from hearted oxygen sensor.
2. Remove heated oxygen sensor using a socket designed for
heated oxygen sensor removal and installation (Service tool).

ECM0388

CAUTION:
Handle it carefully and avoid impacts.

EC-76
REMOVAL AND INSTALLATION OF ECM COMPONENTS

Removal and Installation of Throttle Position

Sensor (Electric Throttle Control Actuator
Assembly)
Refer to "Removal and Installation" in EF section.

Removal and Installation of Accelerator

Pedal Position Sensor (Accelerator Pedal
Assembly)
CAUTION:
Do not disassemble accelerator pedal assembly and remove
sensors and switches.

Removal and Installation of Intake Air

Temperature Sensor (with Mass Air Flow
Sensor)
• Refer to (EC-76), "Removal and Installation of Mass Air Flow
Sensor" because intake air temperature sensor is joined with
mass air flow sensor.

Removal and Installation of Ignition Coil

(with Power Transistor)

Removal and Installation of Fuel Injector

Refer to "Removal and Installation" in EF section.

Removal and Installation of Fuel Pump

Removal and Installation of Throttle Control

Motor (Electric Throttle Control Actuator
Assembly)
Refer to "Removal and installation of throttle position sensor (electric
throttle control actuator assembly)" in EF section.

Removal and Installation of LPG Injector

Holder
Removal
1. Remove air duct from air horn.
2. Remove harness connectors of mass air flow sensor, LPG
injector, and LPG fuel pressure sensor.
3. Loosen air horn bolts and remove air horn.
4. Loosen and remove LPG injector holder bolt.

Installation
NOTE:
• Uniformly tighten bolts diagonally in several steps.

EC-77
REMOVAL AND INSTALLATION OF ECM COMPONENTS

CAUTION:
• Make sure that there is no moisture around connector
when removing and installing each connector. Completely
wipe off water drops if there are any.
• Do not apply voltage to each terminal.

ECM0156

Removal and Installation of LPG Injector

Drive Unit
Refer to EF-11, "Removal and installation" of LPG Injector Drive Unit
Connector.

EC-78
 SERVICE DATA AND SPECIFICATIONS (SDS)

SERVICE DATA AND SPECIFICATIONS (SDS) Standard, Repair Limit

Fuel pressure [kPa (bar, kg/cm2, psi)] 0.35{3.6}

Idle speed (rpm) M/T model (at neutral) 700±50

A/T model (at N position) 700±50
Ignition timing (°BTDC/rpm) M/T model (at neutral) 0±2/700
A/T model (at N position) 0±2/700
Firing order 1-3-4-2
Spark plug Manufacturer/type/gap mm (in) NGK/FR2A-D/0.8 - 0.9 (0.0031 - 0.035)
Ignition advance device Electronically controlled ignition advance
Density of CO at idle speed (%) /Density of HC at idle speed (ppm) 0.1/50 or less

EC-79