GROUP INDEX

General . . . . . . . . . . . . . . . . . . . . . . . . 00
LANCER Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

WORKSHOP MANUAL
SUPPLEMENT

FOREWORD
This Workshop manual contains procedures for
service mechanics, including removal, disassembly,
inspection, adjustment, reassembly and installation.
Use the following manuals in combination with this
manual as required.

TECHNICAL INFORMATION MANUAL

PYME0302
PYME0302-A
PYME0302-B

WORKSHOP MANUAL
CHASSIS GROUP PWME0302
PWME0302-A
PWME0302-B
BODY REPAIR MANUAL
PBME0302
PBME0302-A
PBME0302-B
PARTS CATALOGUE
B606K006A_

All information, illustrations and product descriptions

contained in this manual are current as at the time of
publication. We, however, reserve the right to make
changes at any time without prior notice or obligation.

©Mitsubishi Motors Corporation Oct. 2005

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 00-1

GROUP 00

GENERAL
CONTENTS

VEHICLE IDENTIFICATION . . . . . . . 00-2 GENERAL DATA AND

SPECIFICATIONS . . . . . . . . . . . . . . . 00-3

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 00-2 GENERAL
VEHICLE IDENTIFICATION

VEHICLE IDENTIFICATION
M1001000401448

MODELS
Model code Engine model Price class Transmission model Fuel supply
system
CS9A SRHML6 4G63-DOHC (1,997 mL) Intense F4A4B MPI
<2WD, 4A/T>
No. Item Content
MODEL CODE 1 Development CS: MITSUBISHI LANCER
2 Engine type 9: 1,997mL
3 Sort A: Passenger car
CS 9 W L N H M L 6
4 Body style S: 4-door sedan
5 Transmission R: 4-speed automatic
type transmission
1 2 3 4 5 6 7 8 9 6 Trim level H: Intense
7 Specification M: MPI-DOHC
AC303950AC engine feature
8 Steering wheel L: Left hand
location
9 Destination 6: For Europe

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 GENERAL
GENERAL DATA AND SPECIFICATIONS
00-3
GENERAL DATA AND SPECIFICATIONS
M1001000901197

7
1 3 4 5 9
2 6

AC303990AB

Items CS9A
SRHML6
Vehicle dimensions mm Front track 1 1,470
Overall width 2 1,715
Front overhang 3 965
Wheel base 4 2,600
Rear overhang 5 970
Overall length 6 4,535
Ground clearance (unladen) 7 135
Overall height (unladen) 8 1,415
Rear track 9 1,470
Vehicle weight kg Kerb weight 1,295
Max. gross vehicle weight 1,770
Max. axle weight rating-front 930
Max. axle weight rating-rear 840
Max. trailer weight With brake 1,000
Without brake 400
Max. trailer-nose weight 60
Seating capacity 5
Engine Model code 4G63
Total displacement mL 1,997
Maximum output kW/r/min 99/5,750
Maximum torque N⋅m/r/min 176/4,500
Transmission Model code F4A4B
Type 4-speed automatic
Fuel system Fuel supply system MPI
Maximum speed km/h 187
Minimum turning radius m 5.7

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 NOTES

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 13D-1

MULTIPOINT FUEL
INJECTION (MPI)
<4G63> CONTENTS

GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Basic Idle Speed Adjustment . . . . . . . . . . . . . . . . . . 91

Fuel Pressure Test . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Outline of Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . 95
GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . 3 Engine Control Relay Continuity Check . . . . . . . . . 96
SERVICE SPECIFICATIONS . . . . . . . . . . . . . . . . . 6 Fuel Pump Relay Continuity Check . . . . . . . . . . . . . 96
Intake Air Temperature Sensor Check . . . . . . . . . . 97
SEALANT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Engine Coolant Temperature Sensor Check . . . . . 98
SPECIAL TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Throttle Position Sensor Check . . . . . . . . . . . . . . . . 98
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . 10 Oxygen Sensor Check . . . . . . . . . . . . . . . . . . . . . . . 99
Injector Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
ON-VEHICLE SERVICE . . . . . . . . . . . . . . . . . . . . 90
Idle Speed Control (ISC) Servo (Stepper Motor)
Throttle Body (Throttle Valve Area) Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Purge Control Solenoid Valve Check . . . . . . . . . . 104
Throttle Position Sensor Adjustment . . . . . . . . . . . . 90 EGR Control Solenoid Valve Check . . . . . . . . . . . 104

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 13D-2 MPI <4G63> ï General

GENERAL
OUTLINE OF CHANGE
Following service procedures have been established due to the addition of vehicles with 4G63-MPI engine
for Russia.

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 MPI <4G63> ï General Information 13D-3
GENERAL INFORMATION
The Multipoint Fuel Injection System consists carries out activities such as fuel injection
of sensors which detect the engine conditions, control, idle speed control and ignition timing
the engine-A/T-ECU which controls the system control. In addition, the engine-A/T-ECU is
based on signals from these sensors, and equipped with several diagnosis modes which
actuators which operate under the control of simplify troubleshooting when a problem
the engine-A/T-ECU. The engine-A/T-ECU develops.

FUEL INJECTION CONTROL

The injector drive times and injection timing engine-A/T-ECU provides a richer air/fuel
are controlled so that the optimum air/fuel mixture by carrying out “open-loop” control
mixture is supplied to the engine to correspond when the engine is cold or operating under
to the continually-changing engine operation high load conditions in order to maintain engine
conditions. performance. In addition, when the engine is
A single injector is mounted at the intake port warm or operating under normal conditions,
of each cylinder. Fuel is sent under pressure the engine-A/T-ECU controls the air/fuel mixture
from the fuel tank by the fuel pump, with the by using the oxygen sensor signal to carry out
pressure being regulated by the fuel pressure “closed-loop” control in order to obtain the
regulator. The fuel thus regulated is distributed theoretical air/fuel mixture ratio that provides
to each of the injectors. the maximum cleaning performance from the
Fuel injection is normally carried out once for three way catalyst.
each cylinder for every two rotations of the
crankshaft. The firing order is 1ï3ï4ï2. This
is called sequential fuel injection. The

IDLE AIR CONTROL

The idle speed is kept at the optimum speed conditioner load. In addition, when the air
by controlling the amount of air that bypasses conditioner switch is turned off and on while
the throttle valve in accordance with changes the engine is idling, the idle speed control motor
in idling conditions and engine load during operates to adjust the throttle valve bypass
idling. The engine-A/T-ECU drives the idle air amount in accordance with the engine load
speed control motor to keep the engine running conditions in order to avoid fluctuations in the
at the pre-set idle target speed in accordance engine speed.
with the engine coolant temperature and air

IGNITION TIMING CONTROL

The power transistor located in the ignition engine operating conditions. The ignition timing
primary circuit turns ON and OFF to control is determined by the engine-A/T-ECU from the
the primary current flow to the ignition coil. This engine speed, intake air volume, engine coolant
controls the ignition timing in order to provide temperature and atmospheric pressure.
the optimum ignition timing with respect to the

SELF-DIAGNOSIS FUNCTION
D When an abnormality is detected in one code corresponding to the abnormality is
of the sensors or actuators related to output.
emission control, the engine warning lamp D The RAM data inside the engine-A/T-ECU
(check engine lamp) illuminates as a that is related to the sensors and actuators
warning to the driver. can be read by means of the M.U.T.-II/III.
D When an abnormality is detected in one In addition, the actuators can be
of the sensors or actuators, a diagnosis force-driven under certain circumstances.

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 13D-4 MPI <4G63> ï General Information

OTHER CONTROL FUNCTIONS

1. Fuel Pump Control 3. Fan Motor Control
Turns the fuel pump relay ON so that current The revolutions of the radiator fan and
is supplied to the fuel pump while the engine condenser fan are controlled in response to
is cranking or running. the engine coolant temperature and vehicle
2. A/C Relay Control speed.
Turns the compressor clutch of the A/C 4. Purge Control Solenoid Valve Control
ON and OFF. 5. EGR Control Solenoid Valve Control

GENERAL SPECIFICATIONS
Item Specification

Throttle body Throttle bore mm 60

Throttle position sensor Variable resistor type

Idle speed control servo Stepper motor type

Engine-A/T- Identification No. E6T37983

ECU

Sensors Air flow sensor Karman vortex type

Barometric pressure sensor Semiconductor type

Intake air temperature sensor Thermistor type

Engine coolant temperature sensor Thermistor type

Oxygen sensor Zirconia type

Inhibitor switch Contact switch type

Camshaft position sensor Hall element type

Crank angle sensor Hall element type

Detonation sensor Piezoelectric type

Power steering fluid pressure switch Contact switch type

Actuators Engine control relay Contact switch type

Fuel pump relay Contact switch type

Injector type and number Electromagnetic type, 4

Injector identification mark HDA250E
EGR control solenoid valve Duty cycle type solenoid valve

Purge control solenoid valve Duty cycle type solenoid valve

Fuel pressure Regulator pressure kPa 328

regulator

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 MPI <4G63> ï General Information 13D-5
MULTI-POINT FUEL INJECTION SYSTEM DIAGRAM
L1 Oxygen sensor (front) l1 Injector
L2 Oxygen sensor (rear) l2 Idle speed control servo
L3 Air flow sensor Engine-A/T-ECU (Stepper motor)
L4 Intake air temperature sensor l3 EGR control solenoid valve
L5 Throttle position sensor l4 Purge control solenoid valve
L6 Camshaft position sensor
L7 Crank angle sensor
L8 Barometric pressure sensor
L9 Engine coolant temperature sensor D Engine control relay
L10 Detonation sensor D Fuel pump relay
D A/C compressor relay
D Ignition coil
D Power supply D Fan controller
D Ignition switch-IG D Air flow sensor filter reset signal
D Ignition switch-ST D Engine warning lamp
D A/C switch D Diagnosis output
D A/C load signal D Alternator G terminal
D Power steering fluid pressure switch D Oxygen sensor (front) heater
D Alternator FR terminal D Oxygen sensor (rear) heater
D Vehicle speed sensor D Tachometer

L4 Intake air temperature sensor

l2 Idle speed control servo L3 Air flow sensor
(Stepper motor)
L8 Barometric
L6 Camshaft position sensor L5 Throttle position pressure sensor
sensor

Fuel pressure Air

regulator M M A

To From
fuel tank fuel pump

EGR valve
L1 Oxygen sensor Canister
(front)

l1 Injector
Catalytic L9 Engine coolant l3 EGR control
converter temperature sensor solenoid valve
L10 Detonation sensor l4 Purge control
solenoid valve
L7 Crank angle sensor
L2 Oxygen sensor (rear)

Catalytic converter

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 13D-6 MPI <4G63> ï Service Specifications/Sealant

SERVICE SPECIFICATIONS
Items Specifications

Basic idle speed r/min 750 r 50

Throttle position sensor adjusting voltage mV 535 ï 735

Throttle position sensor resistance k: 3.5 ï 6.5

Idle speed control servo coil resistance (at 20_C) : 28 ï 33

Intake air temperature sensor ï20_C 13 ï 17

resistance k:
0_C 5.3 ï 6.7

20_C 2.3 ï 3.0

40_C 1.0 ï 1.5

60_C 0.56 ï0.76

80_C 0.30 ï 0.42

Engine coolant temperature ï20_C 14 ï 17

sensor resistance k:
0_C 5.1 ï 6.5

20_C 2.1 ï 2.7

40_C 0.9 ï 1.3

60_C 0.48 ï 0.68

80_C 0.26 ï 0.36

Oxygen sensor output voltage (at racing) V 0.6 ï 1.0

Oxygen sensor heater front 4.5 ï 8.0

resistance (at 20_C) :
rear 11 ï 18

Fuel pressure kPa Vacuum hose disconnection 324 ï 343 at kerb idle

Vacuum hose connection Approximately 265 at kerb idle

Injector coil resistance (at 20_C) : 10.5 ï 13.5

SEALANT
Item Specified sealant Remark

Engine coolant temperature sensor 3M Nut Locking Part No. 4171 or equivalent Drying sealant
threaded portion

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 MPI <4G63> ï Special Tools 13D-7
SPECIAL TOOLS
Tool Number Name Use
MB991502 M.U.T.-II sub D Reading diagnosis code
assembly D MPI system inspection
D Measurement of fuel pressure

MB991955 M.U.T.-III sub D Reading diagnosis code

A: MB991824 assembly D MPI system inspection
B: MB991827 D Measurement of fuel pressure
C: MB991910
D: MB991911
E: MB991825
F: MB991826
M.U.T.-III sub
assembly
A: Vehicle com-
munication in-
terface (V.C.I.)
B: M.U.T.-III
USB cable
C: M.U.T.-III
main harness A
(Vehicles with
CAN commu-
nication system)
D: M.U.T.-III
main harness B
(Vehicles with-
out CAN com-
munication sys-
tem)
E: M.U.T.-III
measurement
adapter
F: M.U.T.-III
trigger harness

MB991348 Test harness set D Inspection using an oscilloscope

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 13D-8 MPI <4G63> ï Special Tools

Tool Number Name Use

MB991709 Test harness D Measurement of voltage during
troubleshooting
D Inspection using an oscilloscope
D Check of idle speed control servo

MD998478 Test harness D Measurement of voltage during

(3-pin, triangle) Troubleshooting
D Inspection using an oscilloscope

MB991536 Check harness for D Measurement of voltage during

throttle position Troubleshooting
sensor adjustment D Adjusting of throttle position sensor

MD998464 Test harness D Measurement of voltage during

(4-pin, square) Troubleshooting
D Inspection of oxygen sensor (front)

MB991658 Test harness D Measurement of voltage during

Troubleshooting
D Inspection of oxygen sensor (rear)

A MB991223 Harness set D Check at the ECU terminals

A: MB991219 A: Test harness A: Connector pin contact pressure inspection
B: MB991220 B: LED harness B: Power circuit inspection
C: Power circuit inspection
C: MB991221 C: LED harness D: Commercial tester connection
D: MB991222 adapter
D: Probe
B

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 MPI <4G63> ï Special Tools 13D-9

Tool Number Name Use

MD998709 Adaptor hose Measurement of fuel pressure

MD998742 Hose adaptor

MB991637 Fuel pressure

gauge set

MB991981 Fuel pressure

gauge set

MB992076 Injector test set Checking the spray condition of injectors

MB991607 Injector test

harness

MD998741 Injector test

adaptor

MB991976 Injector test holder

assembly

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 13D-10 MPI <4G63> ï Troubleshooting

Engine warning lamp TROUBLESHOOTING

(check engine lamp)
DIAGNOSIS TROUBLESHOOTING FLOW
Refer to GROUP 00 ï How to Use Troubleshooting/Inspection
Service Point.
NOTE
If the engine-A/T-ECU is replaced, ring antenna with built
in immobilizer-ECU should be replaced, ignition key can be
kept, but must be registered.

DIAGNOSIS FUNCTION
ENGINE WARNING LAMP (CHECK ENGINE LAMP)
If an abnormality occurs in any of the following items related
to the MPI system, the engine warning lamp will illuminate
or flash. If the lamp remains illuminated or if the lamp
illuminates while the engine is running, check the diagnosis
code output.
However, the warning lamp will illuminate as bulb check for
five seconds whenever the ignition switch is turned to the
ON position.

Engine warning lamp inspection items

Engine-A/T-ECU

Oxygen sensor (front)

Air flow sensor

Intake air temperature sensor

Throttle position sensor

Engine coolant temperature sensor

Crank angle sensor

Camshaft position sensor

Barometric pressure sensor

Detonation sensor

Ignition coil, power transistor unit

Injector

Immobilizer system

Oxygen sensor (rear)

NOTE
If the engine warning lamp illuminates because of a malfunction of the engine-A/T-ECU, communication
between M.U.T.-II/III and the engine-A/T-ECU is impossible. In this case, the diagnosis code cannot
be read.

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 MPI <4G63> ï Troubleshooting 13D-11
METHOD OF READING AND ERASING DIAGNOSIS
CODES
Refer to GROUP 00 ï How to Use Troubleshooting/Inspection
Service Points.

INSPECTION USING M.U.T.-II/III DATA LIST AND

ACTUATOR TESTING
1. Carry out inspection by means of the data list and the
actuator test function. If there is an abnormality, check
and repair the chassis harnesses and components.
2. After repairing, re-check using the M.U.T.-II/III and check
that the abnormal input and output have returned to normal
as a result of the repairs.
3. Erase the diagnosis code memory.
4. Remove the M.U.T.-II/III, and then start the engine again
and carry out a road test to confirm that the problem
has disappeared.

FAIL-SAFE FUNCTION REFERENCE TABLE

When the main sensor malfunctions are detected by the diagnosis function, the vehicle is controlled
by means of the pre-set control logic to maintain safe conditions for driving.

Malfunctioning item Control contents during malfunction

Air flow sensor 1. Uses the throttle position sensor signal and engine speed signal (crank angle sensor
signal) to take reading of the basic injector drive time and basic ignition timing from
the pre-set mapping.
2. Fixes the ISC servo in the appointed position so idle control is not performed.

Intake air temperature Controls as if the intake air temperature is 25_C.

sensor

Throttle position No increase in fuel injection amount during acceleration due to the throttle position sensor
sensor (TPS) signal.

Engine coolant Controls as if the engine coolant temperature is 80_C.

temperature sensor

Camshaft position Injects fuel into the cylinders in the order 1-3-4-2 with irregular timing.
sensor (However, after the ignition switch is turned to ON, the No. 1 cylinder top dead centre is not
detected at all.)

Barometric pressure Controls as if the barometric pressure is 101 kPa.

sensor

Detonation sensor Switches the ignition timing from ignition timing for super petrol to ignition timing for standard
petrol.

Ignition coil, power Cuts off the fuel supply to cylinders with an abnormal ignition.
transistor

Alternator FR terminal Does not control the output of the alternator according to an electrical load. (works as a
normal alternator)

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 13D-12 MPI <4G63> ï Troubleshooting

INSPECTION CHART FOR DIAGNOSIS CODES

Code No. Diagnosis item Reference page

11 Oxygen sensor (front) system 13D-13

12 Air flow sensor system 13D-15

13 Intake air temperature sensor system 13D-16

14 Throttle position sensor system 13D-18

21 Engine coolant temperature sensor system 13D-20

22 Crank angle sensor system 13D-22

23 Camshaft position sensor system 13D-23

24 Vehicle speed signal system 13D-25

25 Barometric pressure sensor system 13D-26

31 Detonation sensor system 13D-28

41 Injector system 13D-29

44 Ignition coil (power transistor) system 13D-30

54 Immobilizer system 13D-31

59 Oxygen sensor (rear) system 13D-32

64 Alternator FR terminal system 13D-34

NOTE
1. Do not replace the engine-A/T-ECU until a through terminal check reveals there are no short/open
circuit.
2. Check that the engine-A/T-ECU earth circuit is normal before checking for the cause of the problem.

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 MPI <4G63> ï Troubleshooting 13D-13
INSPECTION PROCEDURE FOR DIAGNOSIS CODE
Code No. 11 Oxygen sensor (front) system Probable cause
Range of Check D Malfunction of the oxygen sensor (front)
D More than 3 minutes passed after completion of start of engine D Oxygen sensor (front) circuit disconnection,
D The engine coolant temperature is approximately more than 80_C. short-circuit, or connector contact defect.
D Intake air temperature 0 ï 55_C. D Malfunction of the engine-A/T-ECU
D The engine speed is more than 1,800 ï 3,500 r/min.
D The volumetric efficiency is 16 ï 60% or more.
Set Conditions
D For 30 seconds, the oxygen sensor output voltage continues to be 0.5 V or
lower, or 0.5 V or higher.
D The Engine-A/T-ECU monitors for this condition once during the drive cycle.

OK
M.U.T.-II/III Data list Intermittent malfunction
D No. 11 Oxygen sensor (front) (Refer to GROUP 00 ï Points to Note
(Refer to P.13D-66.) for Intermittent Malfunctions.)
NG
NG
Check the following connector: Repair
B-17
OK
NG NG
Measure at the B-17 oxygen sensor Check the following connector: Repair
(front) connector. C-124
D Disconnect connector to measure OK
at the harness side
D Resistance between terminal No. NG
Check the harness between the Repair
2 and earth. oxygen sensor (front) and
OK: Less than 2 : engine-A/T-ECU.
OK
NG
M.U.T.-II/III Data list Replace the engine-A/T-ECU.
D No. 11 Oxygen sensor (front)
(Refer to P.13D-66.)
OK

Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)
OK

(1) NG NG
Measure at the B-17 oxygen sensor Check the following connector: Repair
(front) connector. C-124
D Using the test harness
(MD998464), connect the OK
connector, and measure at the NG
Check the harness between the Repair
pickup harness.
oxygen sensor (front) and
D Engine: After warm-up
engine-A/T-ECU.
(1) Voltage between terminal No. 2
and earth
OK: Less than 0.5 V
(2) Voltage between terminal No. 4
and the earth (2) NG NG
Check the oxygen sensor (front). Replace the oxygen sensor (front).
D At rapid deceleration from 4,000
(Refer to P.13D-99.)
r/min
OK: 200 mV or less OK
D During rapid racing NG
OK: 600 ï 1,000 mV Check the following connector: Repair
C-126
OK
OK
To the next page NG
Check the harness between the Repair
oxygen sensor (front) and
engine-A/T-ECU.

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 13D-14 MPI <4G63> ï Troubleshooting

From the previous page

OK
NG NG
Measure at the C-126 engine-A/T-ECU Check the following connector: Repair
connector. C-126
D Measure the engine-A/T-ECU OK
terminal voltage.
D Engine: After warm-up Check and repair the harness between
D Voltage between terminal No. 71 the oxygen sensor (front) and
and earth. engine-A/T-ECU.
D At rapid deceleration from 4,000
r/min
OK: 200 mV or less
D During rapid racing
OK: 600 ï 1,000 mV
OK
NG
Check the following connectors: Repair
C-124, C-126
OK
NG
M.U.T.-II/III Data list Replace the engine-A/T-ECU.
D No. 11 Oxygen sensor (front)
(Refer to P.13D-66.)
OK

Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)

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 MPI <4G63> ï Troubleshooting 13D-15
Code No. 12 Air flow sensor system Probable cause
Range of Check D Malfunction of the air flow sensor
D The engine speed is more than 500 r/min D Air flow sensor circuit disconnection, short-circuit,
Set Condition or connector contact defect
D The sensor output frequency is less than 3.3 Hz for 4 seconds. D Malfunction of the engine-A/T-ECU

OK
M.U.T.-II/III Data list Intermittent malfunction
D No. 12 Air flow sensor (Refer to GROUP 00 ï Points to Note
(Refer to P.13D-66.) for Intermittent Malfunctions.)
NG
NG
Check the following connector: Repair
B-08
OK
(1) NG OK
Measure at the B-08 air flow sensor Measure at the C-124 engine-A/T-ECU Check the following connector:
connector. connector. C-124
D Disconnect the connector to D Measure the voltage of the OK NG
measure at the harness side engine-A/T-ECU terminal. Repair
(1) Voltage between terminal No. 3 D Ignition switch: ON
and earth D Voltage between terminal No. 65 Check and repair the harness between
(Ignition switch: ON) and earth. the air flow sensor and engine-A/T-
OK: 4.9 ï 5.1 V OK: 4.9 ï 5.1 V ECU.
(2) Voltage between terminal No. 4 NG
and earth
(Ignition switch: ON)
OK: System voltage Check the following connector: NG
(3) Resistance between terminal No. Repair
C-124
5 and earth
OK: Less than 2 : OK
NG
Check the harness between the air Repair
flow sensor and engine-A/T-ECU.
OK
NG
M.U.T.-II/III Data list Replace the engine-A/T-ECU.
D No. 12 Air flow sensor
(Refer to P.13D-66.)
OK
Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)

(2) NG NG
Check the following connector: Repair
B-16X
OK
Check the harness between the air
flow sensor and engine control relay.

(3) NG NG
Check the following connector: Repair
C-122
OK
OK
To the next page NG
Check the harness between the air Repair
flow sensor and engine-A/T-ECU.
OK
NG
M.U.T.-II/III Data list Replace the engine-A/T-ECU.
D No. 12 Air flow sensor
(Refer to P.13D-66.)
OK
Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)

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 13D-16 MPI <4G63> ï Troubleshooting

From the previous page

OK
NG NG
Measure at the B-08 air flow sensor Check the following connector: Repair
connector. C-122
D Using the test harness OK
(MB991709), connect the NG
connector, and measure at the Check the harness between the air Repair
pickup. flow sensor and engine-A/T-ECU.
D Ignition switch: ON
OK
D Voltage between terminal No. 7
and earth. Replace the air flow sensor.
OK: 7 ï 8 V
OK

NG NG
Measure at the B-08 air flow sensor Check the following connector: Repair
connector. C-122
D Using the test harness
(MB991709), connect the OK
NG
connector, and measure at the Check the harness between air flow Repair
pickup harness. sensor and engine-A/T-ECU.
D Voltage between terminal No. 7
and earth. OK
OK: Engine: idle NG
0 ï 1 V M.U.T.-II/III Data list Replace the engine-A/T-ECU.
Engine: 3,000 r/min D No. 12 Air flow sensor
6 ï 9 V (Refer to P.13D-66.)
OK OK

Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)

NG
Measure the output waveform at the Replace the air flow sensor.
B-08 air flow sensor connector (using
an analyzer). OK
D Using the test harness Check the trouble symptom. End
(MB991709), connect the
connector, and measure at the NG
pickup harness. NG
D Engine: Idle Check the following connectors: Repair
D Voltage between terminal No. 3 B-16X, C-122, C-124
and earth. OK
OK: Output the waveform as NG
shown on P.13D-79 (in- Check the harness between the air Repair
spection procedure by ana- flow sensor and engine control relay.
lyzer), and check that there
is noise in the output wave- OK
form.
Check the harness between the air
OK flow sensor and engine-A/T-ECU.

M.U.T.-II/III Data list NG

D No. 12 Air flow sensor Replace the engine-A/T-ECU.
(Refer to P.13D-66.)
OK

Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)

Code No. 13 Intake air temperature sensor system Probable cause

Range of Check D Malfunction of the intake air temperature sensor
D 60 seconds after the ignition switch is set to the “ON” position, or after the D Intake air temperature sensor circuit disconnection,
completion of the start of engine. short-circuit, or connector contact defect
Set Conditions D Malfunction of the engine-A/T-ECU
D The sensor output voltage is more than 4.6 V for 4 seconds (Equivalent to intake
air temperature less than ï40_C)
or
D The sensor output voltage is less than 0.2 V for 4 seconds (Equivalent to intake
air temperature of more than 120_C)

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 MPI <4G63> ï Troubleshooting 13D-17
OK
M.U.T.-II/III Data list Intermittent malfunction
D No. 13 Intake air temperature (Refer to GROUP 00 ï Points to Note
sensor for Intermittent Malfunctions.)
OK: Ambient temperature (More
or less the same as the air
temperature)
NG
NG
Check the following connector: Repair
B-08
OK
NG
Check the intake air temperature Replace the intake air temperature
sensor alone. (Refer to P.13D-97.) sensor.
OK
(1) NG NG
Measure at the B-08 air flow sensor Check the following connector: Repair
connector. C-122
D Disconnect the connector to
OK
measure at the harness side
(1) Resistance between terminal No. NG Repair
Check the harness between the air
5 and earth flow sensor and engine-A/T-ECU.
OK: Less than 2 :
(2) Voltage between terminal No. 6 OK
and earth NG
(Ignition switch: ON) M.U.T.-II/III Data list Replace the engine-A/T-ECU.
OK: 4.5 ï 4.9 V D No. 13 Intake air temperature
sensor
OK: Ambient temperature (More
or less the same as the air
temperature)
OK
Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)

(2) NG OK
Measure at the C-124 engine-A/T-ECU Check the following connector:
connector. C-124
D Measure the engine-A/T-ECU OK NG
terminal voltage. Repair
D Disconnect the B-08 air flow
sensor connector.
Check and repair the harness between
D Ignition switch: ON
the air flow sensor and engine-A/T-
D Voltage between terminal No. 64
ECU.
and earth.
OK: 4.5 ï 4.9 V
NG
NG
Check the following connector: Repair
C-124
OK
OK NG
Check the harness between the air Repair
To the next page flow sensor and engine-A/T-ECU.
OK
NG
M.U.T.-II/III Data list Replace the engine-A/T-ECU.
D No. 13 intake air temperature
sensor
OK: Ambient temperature (More
or less the same as air
temperature)
OK
Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)

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 13D-18 MPI <4G63> ï Troubleshooting

From the previous page

OK
NG NG
Measure at the B-08 air flow sensor Check the following connectors: Repair
connector. C-122, C-124
D Using the test harness
OK
(MB991709), connecting only
connector terminals No. 5 and Check and repair the harness between
No. 6, and measure at the the air flow sensor and engine-A/T-
pickup harness. ECU.
D Ignition switch: ON
D Voltage between terminal No. 6
and earth.
OK: Ambient temperature ï20_C
3.8 ï 4.4 V
Ambient temperature 0_C
3.2 ï 3.8 V
Ambient temperature 20_C
2.3 ï 2.9 V
Ambient temperature 40_C
1.5 ï 2.1 V
Ambient temperature 60_C
0.8 ï 1.4 V
Ambient temperature 80_C
0.4 ï 1.0 V
OK
NG
M.U.T.-II/III Data list Replace the engine-A/T-ECU.
D No. 13 intake air temperature
sensor
OK: Ambient temperature (More
or less the same as the air
temperature)
OK

Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)

Code No. 14 Throttle position sensor system Probable cause

Range of Check D Malfunction of the throttle position sensor
D 60 seconds after the ignition switch is set to the “ON” position, or after the D Improper connector contact, open circuit or
completion of start of engine. short-circuited harness wire
Set Conditions D Malfunction of the engine-A/T-ECU
D The sensor output voltage is 4.3 V or more for 4 seconds and volumetric
efficiency 40 % or less.
or
D The sensor output voltage is 0.2 V or less for 2 seconds

OK
M.U.T.-II/III Data list Intermittent malfunction
14 Throttle position sensor (Refer to GROUP 00 ï Points to
(Refer to P.13D-66, DATA LIST Note for Intermittent Malfunctions.)
REFERENCE TABLE.)
NG
NG
Check the throttle position sensor. Replace
(Refer to P.13D-98.)
OK
NG
Check the following connector: Repair
B-06
OK
To the next page

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 MPI <4G63> ï Troubleshooting 13D-19
From the previous page
OK
(1) NG OK
Measure at throttle position sensor Measure at engine-A/T-ECU Check the following connector:
connector B-06. connector C-124. C-124
D Disconnect the connector and D Measure the voltage at the
OK NG
measure at the harness side. engine-A/T-ECU terminals.
(1) Voltage between terminal 1 and D Ignition switch: ON Repair
earth D Voltage between terminal 46 and Check the harness wire between the
(Ignition switch: ON) earth throttle position sensor and the
OK: 4.9 ï 5.1 V OK: 4.9 ï 5.1 V engine-A/T-ECU, and repair if
(2) Resistance between terminal 4 necessary.
and earth NG
OK: 2 : or less NG
Check the following connector: Repair
C-124
OK
NG
Check the harness wire between the Repair
throttle position sensor and the
engine-A/T-ECU.
OK
NG
Check the trouble symptoms. Replace the engine-A/T-ECU.

(2) NG NG
Check the following connector: Repair
C-124
OK NG Repair
Check the harness wire between the
throttle position sensor and the
engine-A/T-ECU.
OK
OK NG
Check the trouble symptoms. Replace the engine-A/T-ECU.

(1) NG NG
Measure at throttle position sensor Check the following connector: Repair
connector B-06. (2) NG C-124
D Use test harness (MB991536) to
connect the connector, and OK
measure at the pick-up harness.
D Ignition switch: ON Check the harness wire between the
(1) Voltage between terminal 1 and throttle position sensor and the
earth engine-A/T-ECU.
OK: 4.9 ï 5.1 V
(2) Voltage between terminal 4 and (3) NG
earth Adjust the throttle position sensor.
OK: 0.5 V or less (Refer to P.13D-98.)
(3) Voltage between terminal 2 and
earth NG
OK: Accelerator pedal fully re- Check the following connector: Repair
leased: 0.335 ï 0.935 V C-126
Accelerator pedal fully de- OK
pressed: 4.4 ï 5.3 V
OK Check the harness wire between the
throttle position sensor and the
To the next page engine-A/T-ECU, and repair if
necessary.

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 13D-20 MPI <4G63> ï Troubleshooting

From the previous page

OK
NG
Measure at the engine-A/T-ECU NG Check the following connector: Repair
connector C-126 C-126
D Measure voltage at the OK
engine-A/T-ECU terminal.
D Ignition switch: ON Check the harness wire between the
D Voltage between terminal 78 and throttle position sensor and the
earth engine-A/T-ECU, and repair if
OK: Accelerator pedal fully re- necessary.
leased: 0.335 ï 0.935 V
Accelerator pedal fully de- OK NG
Check the following connectors: Repair
pressed: 4.4 ï 5.3 V C-124, C-126
OK

Check the trouble symptoms.

NG

Replace the engine-A/T-ECU.

Code No. 21 Engine coolant temperature sensor system Probable cause

Range of Check D Malfunction of the engine coolant temperature
D 60 seconds after the ignition switch is set to the “ON” position, or after the sensor
completion of start of engine. D Open or short circuit in the engine coolant
Set Conditions temperature sensor circuit or loose connector
D The sensor output voltage is 4.6 V or more for 4 seconds (equivalent to contact
ï45_C or lower of engine coolant temperature) D Malfunction of the engine-A/T-ECU
or
D The sensor output voltage is 0.1 V or less for 4 seconds (equivalent to
140_C or higher of engine coolant temperature)
Range of Check
D Engine: After starting
Set Condition
D The engine coolant temperature has reduced from over 40_C to less than
40_C, and that condition has lasted for five minutes or more.

OK
M.U.T.-II/III Data list Intermittent malfunction
21 Engine coolant temperature (Refer to GROUP 00 ï Points to
sensor Note for Intermittent Malfunctions.)
OK: When the engine is cold,
the temperature is roughly
the same as ambient tem-
perature. If warm, it is 80 ï
120_C.
NG
NG
Measure at engine coolant Replace
temperature sensor connector
B-111.
D Disconnect the connector and
measure at the sensor side.
D Resistance between terminals 1
and 2
OK: At 20_C of engine coolant
temperature: 2.1 ï 2.7 k:
At 80_C of engine coolant
temperature:
0.26 ï 0.36 k:
OK NG
Check the following connector: Repair
B-111
OK

To the next page

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 MPI <4G63> ï Troubleshooting 13D-21
From the previous page
OK
(1) NG OK
Measure at engine coolant Measure at engine-A/T-ECU Check the following connector:
temperature sensor connector B-111. connector C-124. C-124
D Disconnect the connector and D Measure the voltage at the OK NG
measure at the harness side. engine-A/T-ECU terminal. Repair
(1) Voltage between terminal 1 and D Disconnect connector B-111.
earth D Ignition switch: ON Check the harness wire between the
(Ignition switch: ON) D Voltage between terminal 44 and engine coolant temperature sensor
OK: 4.5 ï 4.9 V earth and the engine-A/T-ECU, and repair
(2) Resistance between terminal 2 OK: 4.5 ï 4.9 V if necessary.
and earth NG
OK: 2 : or less
Check the following connector: NG
C-124 Repair

OK

Check the harness wire between the NG

engine coolant temperature sensor Repair
and the engine-A/T-ECU.
OK
NG
Check the trouble symptoms. Replace the engine-A/T-ECU.
(2) NG NG
Check the following connector: Repair
C-124
OK

Check the harness wire between the NG

OK engine coolant temperature sensor Repair
and the engine-A/T-ECU.
OK
NG
Check the trouble symptoms. Replace the engine-A/T-ECU.

NG
Measure at engine coolant Check the engine coolant NG
temperature sensor connector B-111. temperature sensor. Repair
D Use test harness (MB991658) to (Refer to P.13D-98.)
connect the connector, and OK
measure at the pick-up harness.
D Ignition switch: ON Check the following connector: NG
D Voltage between terminal 1 and Repair
C-124
earth
OK: At 0_C of engine coolant OK
temperature: 3.2 ï 3.8 V Check the harness wire between the
At 20_C of engine coolant engine coolant temperature sensor
temperature: 2.3 ï 2.9 V and the engine-A/T-ECU, and repair
At 40_C of engine coolant if necessary.
temperature: 1.3 ï 1.9 V
At 80_C of engine coolant
temperature: 0.3 ï 0.9 V
OK
NG
Check the trouble symptoms. Replace the engine-A/T-ECU.

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 13D-22 MPI <4G63> ï Troubleshooting

Code No. 22 Crank angle sensor system Probable cause

Range of Check D Malfunction of the crank angle sensor.
D Engine is cranking D Open or short circuit in the crank angle sensor
Set Condition circuit or loose connector contact.
D Sensor output voltage does not change for 4 seconds (no pulse signal input). D Malfunction of the engine-A/T-ECU

OK
M.U.T.-II/III Data list Intermittent malfunction
22 Crank angle sensor (Refer to GROUP 00 ï Points to
OK: Refer to P.13D-66, DATA Note for Intermittent Malfunctions.)
LIST REFERENCE TABLE.
NG
NG
Check the following connector: Repair
B-116
OK
(1) NG
Measure at the crank angle sensor Check the harness between the
connector B-116. crank angle sensor and earth, and
D Disconnect the connector and repair if necessary.
measure at the harness side.
(1) The resistance between terminal (2) NG OK
1 and earth Measure at the engine-A/T-ECU Check the following connector:
OK: 2 : or less connector C-124. C-124
(2) The voltage between terminal 2 D Measure the voltage at the
OK NG
and earth engine-A/T-ECU terminal.
Repair
(Ignition switch: ON) D Disconnect the connector B-116
OK: 4.9 ï 5.1 V D Ignition switch: ON
D The voltage between terminal 45 Check the harness wire between the
(3) The voltage between terminal 3
and earth crank angle sensor and the
and earth
OK: 4.9 ï 5.1 V engine-A/T-ECU, and repair if
(Ignition switch: ON)
necessary.
OK: System voltage NG
NG
Check the following connector: Repair
C-124
OK
NG
Check the harness wire between the Repair
crank angle sensor and the
engine-A/T-ECU.
OK
NG
Check the trouble symptoms. Replace the engine-A/T-ECU.

(3) NG NG
Check the following connector: Repair
B-16X
OK

Check the harness wire between the

OK crank angle sensor and the engine
control relay, and repair if necessary.
To the next page

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 MPI <4G63> ï Troubleshooting 13D-23
From the previous page
OK
NG NG
Use an analyzer to measure the Check the crank angle sensor vane. Replace
output waveform at the crank angle
sensor connector B-116. OK
D Use the test harness
Replace the crank angle sensor.
(MD998478) to connect the
connector, and measure at the
pick-up harness side. Check the trouble symptoms.
D Engine: Idling
D The voltage between terminal 2 NG
and earth NG
Check the following connectors: Repair
OK: A normal waveform should
be displayed as described B-16X, C-124
on P.13D-81 (Inspection OK
Procedure Using an Ana-
lyzer). Its maximum value Check the harness wires between
should be 4.8 V or more, the crank angle sensor and the
and its minimum value engine-A/T-ECU, crank angle sensor
should be 0.6 V or less and the engine control relay, and the
with no noise in waveform. crank angle sensor and earth. Then,
OK repair if necessary.

Check the trouble symptoms.

NG
Replace the engine-A/T-ECU.

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 13D-24 MPI <4G63> ï Troubleshooting

Code No. 23 Camshaft position sensor system Probable cause

Range of Check D Malfunction of the camshaft position sensor
D During engine cranking and driving D Open or short circuit in the camshaft position
Set Condition sensor circuit or loose connector contact.
D The sensor output voltage does not change for 4 seconds (no pulse signal D Malfunction of the engine-A/T-ECU
input).

NG
Check the following connector: Repair
B-107
OK
(1) NG NG
Measure at camshaft position sensor Check the following connector: Repair
connector B-107. B-16X
D Disconnect the connector and OK
measure at the harness side.
(1) The voltage between terminal 3 Check the harness wire between the
and earth camshaft position sensor connector
(Ignition switch: ON) and the engine control relay, and
OK: System voltage repair if necessary.
(2) The voltage between terminal 2
and earth (2) NG Check the following connector:
(Ignition switch: ON) Measure at the engine-A/T-ECU OK
C-124
OK: 4.9 ï 5.1 V connector C-124.
(3) The resistance between terminal D Measure the voltage at the OK NG
1 and earth engine-A/T-ECU terminal. Repair
OK: 2 : or less D Disconnect connector B-107.
D Ignition switch: ON Check the harness wire between the
D The voltage between terminal 56 camshaft position sensor connector
and earth and the engine-A/T-ECU, and repair if
OK: 4.9 ï 5.1 V necessary.
NG
NG
Check the following connector: Repair
C-124
OK
NG
Check the harness wire between the Repair
intermediate connector and the
engine-A/T-ECU.
OK OK
NG
Check the trouble symptoms. Replace the engine-A/T-ECU.

(3) NG
Check the harness wire between the
camshaft position sensor connector
and earth, and repair if necessary.

NG NG
Use an analyzer to measure the Check the camshaft position sensing Replace
output waveform at camshaft position cylinder.
sensor connector B-107.
D Use test harness (MB991709) to OK
connect the connector, and
measure at the pick-up harness. Replace the camshaft position
D Engine: Idling sensor.
D The voltage between terminal 2
and earth
OK: A normal waveform should Check the trouble symptoms.
be displayed as described
NG
on P.13D-81 (Inspection
Procedure Using an Ana- NG
Check the following connectors: Repair
lyzer), its maximum value B-16X, C-124
should be 4.8 V or more,
and its minimum value OK
should be 0.6 V or less
Check the harness wires between the camshaft position sensor connector and the
with no noise in waveform.
engine-A/T-ECU, the camshaft position sensor connector and the engine control relay,
OK and the camshaft position sensor connector and earth. Then, repair if necessary.

OK
Check the trouble symptoms. Intermittent malfunction
(Refer to GROUP 00 ï Points to Note for Intermittent Malfunctions.)
NG

Replace the engine-A/T-ECU.

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 MPI <4G63> ï Troubleshooting 13D-25
Code No. 24 Vehicle speed signal system Probable cause
Range of Check D Malfunction of the output shaft speed sensor
D 60 seconds after the ignition switch is set to the “ON” position, or after the D Open or short circuit in the output shaft speed
completion of start of engine. sensor circuit or loose connector contact
D The engine speed is more than 2,300 r/min. D Malfunction of the engine-A/T-ECU
D Volumetric efficiency 50 % or more
Set Condition
D The vehicle speed signal does not change for 4 seconds (no pulse signal
input.)

YES
M.U.T.-II/III Self-Diag code D Automatic transmission system check
D Is diagnosis code of automatic transmission system output? (Refer to GROUP 23B ï Troubleshooting ï Inspection
chart for diagnosis codes)
NO

OK
Check the trouble symptoms. Intermittent malfunction. (Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)
NG

Replace the engine-A/T-ECU.

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 13D-26 MPI <4G63> ï Troubleshooting

Code No. 25 Barometric pressure sensor system Probable cause

Range of Check D Malfunction of the barometric pressure sensor
D 60 seconds after the ignition switch is set to the “ON” position, or after the D Barometric pressure sensor circuit disconnection,
completion of start of engine. short-circuit, or connector contact defect
D Battery voltage 8 V or more. D Malfunction of the engine-A/T-ECU
Set Conditions
D The sensor output voltage is more than 4.5 V for 4 seconds (Equivalent to
air pressure of more than 114 kPa)
or
D The sensor output voltage is less than 0.2 V for 4 seconds (Equivalent to air
pressure of less than 5 kPa)

OK
M.U.T.-II/III Data list Intermittent malfunction
D No. 25 Barometric pressure (Refer to GROUP 00 ï Points to Note
sensor (Refer to P.13D-66.) for Intermittent Malfunctions.)
NG
NG
Check the following connector: Repair
B-08
OK
(1) NG OK
Measure at the B-08 air flow sensor Measure at the C-124 engine-A/T-ECU Check the following connector:
connector. connector. C-124
D Disconnect the connector to D Measure the engine-A/T-ECU
OK NG
measure at the harness side terminal voltage.
Repair
(1) Voltage between terminal No. 1 D Ignition switch: ON
and earth D Voltage between terminal No. 46
(Ignition switch: ON) and earth Check and repair the harness between
OK: 4.9 ï 5.1 V OK: 4.9 ï 5.1 V the air flow sensor and engine-A/T-
(2) Resistance between terminal No. ECU.
NG
5 and earth.
OK: Less than 2 :
NG
Check the following connector: Repair
C-124
OK
NG
Check the harness between the air Repair
flow sensor and engine-A/T-ECU.
OK
NG
M.U.T.-II/III Data list Replace the engine-A/T-ECU.
D No. 25 Barometric pressure
sensor (Refer to P.13D-66.)
OK

Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)

(2) NG NG
Check the following connector: Repair
C-122
OK OK
NG
Check the harness between the air Repair
To the next page
flow sensor and engine-A/T-ECU.
OK
NG
M.U.T.-II/III Data list Replace the engine-A/T-ECU.
D No. 25 Barometric pressure
sensor (Refer to P.13D-66.)
OK

Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)

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 MPI <4G63> ï Troubleshooting 13D-27
From the previous page
OK
(1) NG NG
Measure at the B-08 air flow sensor Check the following connector: Repair
connector. C-124
D Using the test harness
(MB991709), connect only OK
connector terminals No. 1, No. 2, Check and repair the harness between
and No. 5, and measure at the the air flow sensor and engine-A/T-
pickup harness. ECU.
D Ignition switch: ON
(1) Voltage between terminal No. 1 NG
(2) NG
and earth Check the following connector: Repair
OK: 4.9 ï 5.1 V C-122
(2) Voltage between terminal No. 5
and earth OK
OK: Less than 0.5 V
Check and repair the harness between
(3) Voltage between terminal No. 2 the air flow sensor and engine-A/T-
and earth ECU.
OK: High 0 m 3.8 ï 4.2 V
High 600 m 3.5 ï 3.9 V (3) NG NG
Check the following connector: Repair
High 1,200 m 3.3 ï 3.7 V C-124
High 1,800 m 3.0 ï 3.4 V OK
OK NG
Check the harness between the air Repair
flow sensor and engine-A/T-ECU.
OK
Replace the air flow sensor.

NG NG
Measure at the C-124 engine-A/T-ECU Check the following connector: Repair
connector. C-124
D Measure the engine-A/T-ECU OK
terminal voltage.
D Ignition switch: ON Check and repair the harness between
D Voltage between terminal No. 55 the air flow sensor and engine-A/T-
and earth. ECU.
OK: High 0 m 3.8 ï 4.2 V
High 600 m 3.5 ï 3.9 V
High 1,200 m 3.3 ï 3.7 V
High 1,800 m 3.0 ï 3.4 V
OK
NG
Check the following connectors: Repair
C-122, C-124
OK

M.U.T.-II/III Data list NG

D No. 25 Barometric pressure Replace the engine-A/T-ECU.
sensor (Refer to P.13D-66.)
OK

Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)

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 13D-28 MPI <4G63> ï Troubleshooting

Code No. 31 Detonation sensor system Probable cause

Range of Check D Malfunction of the detonation sensor
D 60 seconds after the ignition switch is set to the “ON” position, or after the D Open or short circuit in the detonation sensor
completion of start of engine. circuit or loose connector contact
D The engine speed is more than 2,500 r/min. D Malfunction of the engine-A/T-ECU
D Volumetric efficiency 30 % or more
Set Condition
D Changes in sensor output voltage (detonation sensor peak voltage per 1/2
crankshaft rotation) in 200 consecutive cycles are 0.078 V or less.

NG
Check the following connector: B-117 Repair
OK
NG
Measure at the detonation sensor connector B-117. Check the harness wire between the detonation sensor and
D Disconnect the connector and measure at the harness earth, and repair if necessary.
side.
D The resistance between terminal 2 and earth
OK: 2 : or less
OK
NG
Check the following connector: C-126 Repair
OK
NG
Check the harness wire between the detonation sensor and Repair
the engine-A/T-ECU.
OK
OK
Check the trouble symptoms. Intermittent malfunction (Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)
NG

Replace the detonation sensor.

Check the trouble symptoms.

NG

Replace the engine-A/T-ECU.

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 MPI <4G63> ï Troubleshooting 13D-29
Code No. 41 Injector system Probable cause
Range of Check D Malfunction of the injector
D Fuel cut and injector not in forced drive (actuator test) mode. D Improper connector contact, open circuit or short-cir-
D The engine speed is 50 ï 1,000 r/min cuited harness wire of the injector circuit
D The throttle position sensor output voltage is 1.15 V or less. D Malfunction of the engine-A/T-ECU
Set Condition
D Surge voltage of injector coil is not detected for 4 seconds.

OK
M.U.T.-II/III Actuator Test Intermittent malfunction
01 No. 1 injector (Refer to GROUP 00 ï Points to Note for Intermittent Malfunctions.)
02 No. 2 injector
03 No. 3 injector
04 No. 4 injector
OK: The idling condition should change
NG
NG
Check the following connectors: Repair
B-02, B-03, B-04, B-05
OK
NG
Check the injector. (Refer to P.13D-101.) Replace
OK
NG
Measure at the injector connector B-02, B-03, B-04, B-05. Check the harness wire between the engine control relay and the
D Disconnect the connector, and measure at the harness side. injector connector, and repair if necessary.
D Voltage between 1 and earth (Ignition switch: ON)
OK: System voltage
OK
NG
Check the following connector: C-122 Repair
OK
NG
Measure at the engine-A/T-ECU connector C-122. Check the harness wire between the engine-A/T-ECU and the
D Disconnect the connector, and measure at the harness side. injector connector, and repair if necessary.
D Voltage between 1, 2, 9, 24 and earth (Ignition switch: ON)
OK: System voltage
OK
Check the trouble symptoms.
NG

Use an analyzer to measure the signal waveform at injector OK Intermittent malfunction

connector B-02, B-03, B-04, B-05. (Refer to GROUP 00 ï Points to Note for Intermittent Malfunctions.)
D Use a test harness (MB991348) to connect the connector, and
measure at the pick-up harness side.
D Engine: Idling
D The voltage between terminal 2 and earth
OK: A normal waveform should be displayed as described
on P.13D-83 (INSPECTION PROCEDURE USING
AN ANALYZER).
NG

Replace the engine-A/T-ECU.

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 13D-30 MPI <4G63> ï Troubleshooting

Code No. 44 Ignition coil system Probable cause

Range of Check D Malfunction of the ignition coil
D The engine speed is 1,500 ï 4,500 r/min D Improper connector contact, open circuit or
D Volumetric efficiency 30 ï 55 % short-circuited harness wire of the ignition primary
D Fuel cut and injector not in forced drive (actuator test) mode. circuit
D The throttle deviation is within the range of ï0.06 V/25 ms to 0.06 V/10 ms. D Malfunction of the spark plug and spark plug cable.
D The coolant temperature is 80_C or higher, and the intake air temperature is ï10_C D Faulty compression
or higher. D Malfunction of the engine-A/T-ECU
Set condition
D After driven for 250 rotations or more in the above check range, crank angle
sensor detects abnormal rotation caused by misfire (one failed coil of the two
coils).

NG
Check the ignition coil. Replace
(Refer to GROUP 16 ï Ignition System.)
OK
(1) NG NG
Measure at the ignition coil connectors Check the following connectors: Repair
B-104, B-113. A-13, C-27, C-210, C-212
D Disconnect the connector, and
OK D Check the harness wire between
measure at the harness side.
NG the ignition coil and ignition
(1) Voltage between 1 and earth Check the trouble symptom.
(Ignition switch: ON) switch connector, and repair if
OK: System voltage necessary.
(2) Voltage between 3 and earth
(Engine: Cranking)
OK: 0.5 ï 4.0 V (2) NG NG
Checkthefollowing connector:C-122 Repair
(3) Continuity between 2 and earth
OK: 2 : or less (3) NG OK
OK Check the trouble symptom.
Check the following connectors: NG
B-104, B-113 NG
Check the harness wire between the Repair
OK NG engine-A/T-ECU and ignition coil con-
nector.
Repair
OK
Check the trouble symptom.
Replace the engine-A/T-ECU.
NG
Check the harness between the ignition
Check the following items in order. coil connector and the earth and repair
D Check the spark plug cables, spark if necessary.
plugs. NG
Repair or Replace
D Check the compression pressure.
OK

Replace the ignition coil.

Check the trouble symptom.

NG

Replace the engine-A/T-ECU.

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 MPI <4G63> ï Troubleshooting 13D-31
Cord No. 54 Immobilizer system Probable cause
Range of Check D Open or short circuit, or loose connector contact
D Ignition switch: ON D Malfunction of the immobilizer-ECU
Set Condition D Malfunction of the engine-A/T-ECU
D Improper communication between the engine-A/T-ECU and the
immobilizer-ECU

NOTE
(1) If the registered ignition keys are close each other when starting the engine, radio interference may
cause this code to be displayed.
(2) This code may be displayed when registering the key encrypted code.

NG
Check the following connectors: Repair
C-13, C-128, C-202
OK
NG
Check the harness wire between the Replace
immobilizer-ECU and the
engine-A/T-ECU.
OK

Check the trouble symptoms.

NG

Replace the immobilizer-ECU.

Check the trouble symptoms.

NG

Replace the engine-A/T-ECU.

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 13D-32 MPI <4G63> ï Troubleshooting

Code No. 59 Oxygen sensor (rear) system Probable cause

Range of Check D Malfunction of the oxygen sensor (rear)
D More than 3 minutes passed after completion of start of engine D Oxygen sensor (rear) circuit disconnection,
D The engine coolant temperature is approximately more than 80_C. short-circuit, or connector contact defect
D Intake air temperature 0 ï 55_C D Malfunction of the engine-A/T-ECU
D The engine speed is more than 1,800 ï 3,500 r/min.
D The volumetric efficiency is 16 ï 60% or more.
D Other than the fuel cut mode
D When 0.2 seconds or more of the fuel cut passed, 30 seconds elapsed after
return.
D The air flow sensor output frequency is 81 Hz or more.
Set Conditions
D When the throttle position sensor is 4.4 V or higher, other than the engine is
idling, and other than in feedback mode, all the following states continue to
be true for 5 seconds or more: the oxygen sensor (front) output voltage is
0.5 V or higher; the oxygen sensor (rear) output voltage is less than 0.1 V;
and the oxygen sensor (rear) output voltage variation is less than 0.078 V.
D When the air/fuel ratio is forcibly turned to a rich state for 10 seconds, all
the following states continue to be true for 5 seconds or more: the oxygen
sensor (front) output voltage is 0.5 V or more; the oxygen sensor (rear)
output voltage is less than 0.1 V; and the oxygen sensor (rear) output
voltage variation is less than 0.078 V.
D The engine-A/T-ECU monitors for this condition once during the drive cycle.

OK
M.U.T.-II/III Data list Intermittent malfunction
D No. 59 Oxygen sensor (rear) (Refer to GROUP 00 ï Points to Note
(Refer to P.13D-66.) for Intermittent Malfunctions.)
NG
NG
Check the following connector: Repair
C-130
OK
NG NG
Measure at the C-130 oxygen sensor Check the following connector: Repair
(rear) connector. C-124
D Disconnect connector to measure OK
at the harness side
D Resistance between terminal No. NG
Check the harness between the Repair
2 and earth. oxygen sensor (rear) and
OK: Less than 2 : engine-A/T-ECU.
OK
NG
M.U.T.-II/III Data list Replace the engine-A/T-ECU.
D No. 59 Oxygen sensor (rear)
(Refer to P.13D-66.)
OK

Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)
OK
(1) NG NG
Measure at the C-130 oxygen sensor Check the following connector: Repair
(rear) connector. C-124
D Using the test harness
(MB991658), connect the OK
connector, and measure at the NG
Check the harness between the Repair
pickup harness.
oxygen sensor (rear) and
D Engine: After warm-up
engine-A/T-ECU.
(1) Voltage between terminal No. 2
and earth
OK: Less than 0.5 V
(2) Voltage between terminal No. 1
and the earth (2) NG NG
Check the oxygen sensor (rear). Replace the oxygen sensor (rear).
D During rapid racing
(Refer to P.13D-100.)
OK: 0 and 600 ï 1,000 mV
alternate. OK
NG
OK Check the following connector: Repair
C-126
To the next page
OK
NG
Check the harness between the Repair
oxygen sensor (rear) and
engine-A/T-ECU.

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 MPI <4G63> ï Troubleshooting 13D-33
From the previous page
OK
NG NG
Measure at the C-126 engine-A/T-ECU Check the following connector: Repair
connector. C-126
D Measure the engine-A/T-ECU OK
terminal voltage.
D Engine: After warm-up Check and repair the harness between
D Voltage between terminal No. 73 the oxygen sensor (rear) and
and earth. engine-A/T-ECU.
D During rapid racing
OK: 0 and 600 ï 1,000 mV
alternate.
OK
NG
Check the following connectors: Repair
C-122, C-124, C-126
OK
NG
M.U.T.-II/III Data list Replace the engine-A/T-ECU.
D No. 59 Oxygen sensor (rear)
(Refer to P.13D-66.)
OK

Intermittent malfunction
(Refer to GROUP 00 ï Points to Note
for Intermittent Malfunctions.)

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 13D-34 MPI <4G63> ï Troubleshooting

Code No. 64 Alternator FR terminal system Probable cause

Range of Check D Open circuit in alternator FR terminal circuit
D During the engine running. D Malfunction of the engine-A/T-ECU
Set Condition
D Input voltage from the alternator FR terminal is system voltage for 20
seconds.

NG
Check the following connector: Repair
B-26
OK
NG Measure at the engine-A/T-ECU OK
Measure at the alternator connector connector C-124. Check the following connectors:
B-26. D Measure the voltage at the B-18, C-124
D Use test harness (MB991519) to engine-A/T-ECU terminal.
connect the connector, and OK NG
D Ignition switch: ON Repair
measure at the pick-up harness. D The voltage between terminal 54
D Ignition switch: ON and earth Check the harness wire between the
D The voltage between terminal 4 OK: 9 ï 10 V alternator connector and the
and earth
engine-A/T-ECU, and repair if
OK: 9 ï 10 V NG
necessary.
OK NG
Check the following connector: Repair
C-124
OK
NG
Check the harness wire between the Repair
alternator connector and the
engine-A/T-ECU.
OK NG
Check the trouble symptoms. Replace the engine-A/T-ECU.

NG
Measure at the alternator connector Check the following connectors: NG
B-26. B-18, C-124 Replace
D Use test harness (MB991519) to
connect the connector, and OK
measure at the pick-up harness.
D Engine: Idling (After warming up) Check the harness wire between the NG
D Radiator fan: Not operating alternator connector and the Repair
D The voltage between terminal 4 engine-A/T-ECU.
and earth OK
OK: The voltage drops when
the headlamps are turned Check the trouble symptoms.
on. NG
OK
Replace the alternator.

OK
Check the trouble symptoms. Intermittent malfunction
(Refer to GROUP 00 ï Points to
NG Note for Intermittent Malfunctions.)
Replace the engine-A/T-ECU.

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 MPI <4G63> ï Troubleshooting 13D-35
INSPECTION CHART FOR TROUBLE SYMPTOMS
Trouble symptom Inspection Reference page
procedure
No.

Communication Communication with all systems is not possible. 1 13D-39

with M.U.T.-II/
M.U.T. II/
III is impossi-
Communication with engine-A/T-ECU only is not possible. 2 13D-39
ble.

Engine warning The engine warning lamp does not illuminate right after the 3 13D-40
lamp and ignition switch is turned to the ON position.
related parts
The engine warning lamp remains illuminating and never goes 4 13D-40
out.

Starting No initial combustion (starting impossible) 5 13D-41

Initial combustion but no complete combustion 6 13D-42

(starting impossible)

Long time to start (improper starting) 7 13D-43

Idling stability Unstable idling (Rough idling, hunting) 8 13D-44

(Improper idling)
Idling speed is high. (Improper idling speed) 9 13D-46

Idling speed is low. (Improper idling speed) 10 13D-46

Idling stability When the engine is cold, it stalls at idling. (Die out) 11 13D-47
(Engine stalls)
When the engine is hot, it stalls at idling. (Die out) 12 13D-48

The engine stalls when starting the car. (Pass out) 13 13D-50

The engine stalls when decelerating. 14 13D-50

Driving Hesitation, sag or stumble 15 13D-51

The feeling of impact or vibration when accelerating 16 13D-52

The feeling of impact or vibration when decelerating 17 13D-52

Poor acceleration 18 13D-53

Surge 19 13D-54

Knocking 20 13D-55

Dieseling 21 13D-55

Too high CO and HC concentration when idling 22 13D-56

Low alternator output voltage (approx. 12.3 V) 23 13D-57

Idling speed is improper when A/C is operating 24 13D-57

Fans (radiator fan, A/C condenser fan) are inoperative 25 13D-58

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 13D-36 MPI <4G63> ï Troubleshooting

PROBLEM SYMPTOMS TABLE (FOR YOUR INFORMATION)

Items Symptom

Starting Won’t start The starter is used to crank the engine, but there is no combustion within the
cylinders, and the engine won’t start.

Fires up and dies There is combustion within the cylinders, but then the engine soon stalls.

Hard starting Engine starts after cranking a while.

Idling Hunting Engine speed doesn’t remain constant; changes at idle.

stability
Rough idle Usually, a judgement can be based upon the movement of the tachometer
pointer, and the vibration transmitted to the steering wheel, shift lever, body,
etc. This is called rough idle.

Incorrect idle The engine doesn’t idle at the usual correct speed.
speed

Engine stall The engine stalls when the foot is taken from the accelerator pedal,
(Die out) regardless of whether the vehicles is moving or not.

Engine stall The engine stalls when the accelerator pedal is depressed or while it is being
(Pass out) used.

Driving Hesitation Sag “Hesitation” is the delay in response of the vehicle speed (engine speed) that
occurs when the accelerator is depressed in order to accelerate from the
speed at which the vehicle is now traveling, or a temporary drop in vehicle
speed (engine speed) during such acceleration.
Serious hesitation is called “sag”. (Refer to Fig. 1)

Poor acceleration Poor acceleration is inability to obtain an acceleration corresponding to the

degree of throttle opening, even though acceleration is smooth, or the inability
to reach maximum speed.

Stumble Engine speed increase is delayed when the accelerator pedal is initially
depressed for acceleration. (Refer to Fig. 2)

Shock The feeling of a comparatively large impact or vibration when the engine is
accelerated or decelerated.

Surge This is repeated surging ahead during constant speed travel or during
variable speed travel.

Knocking A sharp sound like a hammer striking the cylinder walls during driving and
which adversely affects driving.

Stopping Run on The condition in which the engine continues to run after the ignition switch is
(“Dieseling”) turned to LOCK (OFF) position. Also called “Dieseling”.

Fig. 1 Hesitation Fig. 2

Normal
Vehicle Initial ac- Vehicle Normal
speed celerator speed Initial ac-
pedal de-
pression celerator
pedal de-
Sag pression

Idling Stumble

Time Time

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 MPI <4G63> ï Troubleshooting 13D-37
PROBLEM SYMPTOMS TABLE
Inspection Trouble symptom Reference
procedure page
No.

1 Communication with all system is not possible 13D-39

2 Communication with engine-A/T-ECU only is not possible 13D-39

3 The engine warning lamp does not illuminate right after the ignition switch is turned 13D-40
to the “ON” position

4 The engine warning lamp remains illuminating and never goes out 13D-40

5 No initial combustion (Starting impossible) 13D-41

6 Initial combustion but no complete combustion (Starting impossible) 13D-42

7 It takes too long time to start (Incorrect starting) 13D-43

8 Unstable idling (Rough idling, hunting) 13D-44

9 Idling speed is high (Improper idling speed) 13D-46

10 Idling speed is low (Improper idling speed) 13D-46

11 When the engine is cold, it stalls at idling (Die out) 13D-47

12 When the engine is hot, it stalls at idling (Die out) 13D-48

13 The engine stalls when starting the car (Pass out) 13D-50

14 The engine stalls when decelerating 13D-50

15 Hesitation, sag or stumble 13D-51

16 The feeling of impact or vibration when accelerating 13D-52

17 The feeling of impact or vibration when decelerating 13D-52

18 Poor acceleration 13D-53

19 Surge 13D-54

20 Knocking 13D-55

21 Dieseling 13D-55

22 Too high CO and HC concentration when idling 13D-56

23 Low alternator output voltage (approx. 12.3 V) 13D-57

24 Idling speed is improper when A/C is operating 13D-57

25 Fans (radiator fan, A/C condenser fan) are inoperative 13D-58

26 Check the engine-A/T-ECU power supply and earth circuit 13D-59

27 Power supply system and ignition switch-IG system 13D-59

28 Fuel pump system 13D-60

29 Ignition switch-ST and inhibitor switch system 13D-62

30 Power steering fluid pressure switch system 13D-63

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 13D-38 MPI <4G63> ï Troubleshooting

Inspection Trouble symptom Reference

procedure page
No.

31 A/C switch and A/C relay system 13D-63

32 Idle speed control (ISC) servo (Stepper motor) system 13D-64

33 Purge control solenoid valve system 13D-65

34 EGR control solenoid valve system 13D-65

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 MPI <4G63> ï Troubleshooting 13D-39
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
INSPECTION PROCEDURE 1
Communication with M.U.T.-II/III is not possible. Probable cause
(Communication with all systems is not possible.)
The cause is probably a defect in the power supply system (including earth) for the D Malfunction of the connector
diagnosis line. D Malfunction of the harness wire

NG NG
Measure at the diagnosis connector Check the following connectors: Repair
(16-pin) C-11. C-212, C-211, C-21
D Voltage between 16 and earth
OK
OK: System voltage
NG
OK Check the trouble symptom. Check the harness wire between the
power supply and diagnostic connector
(16 pin), and repair if necessary.

NG
Measure at the diagnosis connector Check the harness wire between the
(16-pin) C-11. diagnostic connector (16-pin)andearth,
D Continuity between 4 and earth and repair if necessary.
D Continuity between 5 and earth
OK: Continuity
OK

Replace the M.U.T.-II/III.

INSPECTION PROCEDURE 2
M.U.T.-II/III communication with engine-A/T-ECU is Probable cause
impossible.
One of the following causes may be suspected: D Malfunctionoftheengine-A/T-ECUpowersupplycircuit
D No power supply to engine-A/T-ECU. D Malfunction of the engine-A/T-ECU
D Defective earth circuit of engine-A/T-ECU. D Open circuit between engine-A/T-ECU and diagnosis
D Defective engine-A/T-ECU. connector
D Improper communication line between engine-A/T-ECU and M.U.T.-II/III

NG
Check the following connectors: C-11, C-32, C-13, C-126 Repair
OK

Check the trouble symptom.

NG
OK NG
Check the harness wire between engine-A/T-ECU and diagnosis Check the harness wire Repair
connector. betweenengine-A/T-ECU
NG and earth.
OK
Repair
Check the power supply system and ignition switch-IG system.
(Refer to P.13D-59, INSPECTION PROCEDURE 27.)

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 13D-40 MPI <4G63> ï Troubleshooting

INSPECTION PROCEDURE 3
The engine warning lamp does not illuminate right after Probable cause
the ignition switch is turned to the ON position.
Because there is a burnt-out bulb, the engine-A/T-ECU causes the engine warning D Burnt-out bulb
lamp to illuminate for five seconds immediately after the ignition switch is turned to D Defective warning lamp circuit
ON. If the engine warning lamp does not illuminate immediately after the ignition switch D Malfunction of the engine-A/T-ECU
is turned to ON, one of the malfunctions listed at right has probably occurred.

NG
M.U.T.-II/III Data list Check the engine-A/T-ECU power supply and earth circuit.
16 Engine-A/T-ECU power supply voltage (Refer to P.13D-66.) (Refer to P.13D-59, INSPECTION PROCEDURE 26.)
OK
OK NG
Measure at the engine-A/T-ECU connector C-122. Check the following Repair
D Disconnect the connector, and measure at the harness side. connector: C-122
D Earth the terminal No. 22.
OK
OK: The engine warning lamp illuminates.
NG Check the trouble symptom.
NG
NG
Check a burnt-out bulb. Replace Replace the engine-A/T-ECU.
OK
NG NG
Measure at the combination meter connector C-04. Check the following Repair
D Disconnect the connector, and measure at the harness side. connectors: C-03,
D Voltage between 9 and earth (Ignition switch: ON) C-212, C-210
OK: System voltage
OK
OK
Check the trouble symptom.
NG

Check the engine warning lamp power supply circuit, and repair
if necessary.
NG
Check the following connectors: Repair
C-13, C-122
OK
NG
Check the trouble symptom. Checktheharnesswirebetweencombinationmeterandengine-A/T-
ECU, and repair if necessary.

INSPECTION PROCEDURE 4
The engine warning lamp remains illuminating and never Probable cause
goes out.
In cases such as the above, the cause is probably that the engine-A/T-ECU is detecting D Short-circuit between the engine warning lamp and
a problem in a sensor or actuator, or that one of the malfunctions listed at right has engine-A/T-ECU
occurred. D Malfunction of the engine-A/T-ECU

YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES
NO
NG
Measure at the combination meter connector C-04. Checktheharnesswirebetweencombinationmeterandengine-A/T-
D Disconnect the connector, and measure at the harness side. ECU connector, and repair if necessary.
D Disconnect the engine-A/T-ECU connector
D Continuity between 17 and earth
OK: No continuity
OK

Replace the engine-A/T-ECU.

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 MPI <4G63> ï Troubleshooting 13D-41
INSPECTION PROCEDURE 5
No initial combustion (starting impossible) Probable cause
In cases such as the above, the cause is probably that a spark plug is defective, D Malfunction of the ignition system
or that the supply of fuel to the combustion chamber is defective. D Malfunction of the fuel pump system
In addition, foreign materials (water, kerosene, etc.) may be mixed with the fuel. D Malfunction of the injectors
D Malfunction of the engine-A/T-ECU
D Malfunction of the immobilizer system <Australia>
D Foreign materials in fuel

NG
Check battery voltage when cranking. Check the battery. (Refer to GROUP 54 ï Battery.)
OK: 8 V or higher
OK
YES
Is an immobilizer-ECU diagnosis code displayed? Check the immobilizer.
(Refer to GROUP 54 ï Ignition Key and Immobilizer.)
NO
NG
M.U.T.-II/III Data list Check the power supply system and ignition switch-IG system.
16 Engine-A/T-ECU power supply voltage (Refer to P.13D-66.) (Refer to P.13D-59, INSPECTION PROCEDURE 27.)
OK
NO
Does the camshaft rotate at the engine cranking? (When oil filler Check timing belt for breakage.
cap is removed.)
YES
YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
M.U.T.-II/III Data list Check the crank angle sensor system. (Refer to P.13D-56,INSPEC-
22 Crank angle sensor TION PROCEDURE FOR DIAGNOSIS CODE 22.)
OK: Cranking speed is displayed.
OK
NG
M.U.T.-II/III Actuator test Check the fuel pump system. (Refer to P.13D-60, INSPECTION
07 Fuel pump (Refer to P.13D-70) PROCEDURE 28.)
OK
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system. (Refer to
21 Engine coolant temperature sensor (Refer to P.13D-66.) P.13D-20, INSPECTION PROCEDURE FOR DIAGNOSIS CODE
21.)
OK
NG
Can any sound be heard from the injectors when cranking? Check the injector system. (Refer to P.13D-29, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
NG
Does the engine tachometer display the cranking speed? Check the ignition coil system. (Refer to P.13D-30, INSPECTION
D Set the tachometer of primary voltage detection type. PROCEDURE FOR DIAGNOSIS CODE 44.)
OK
NG
Check the ignition timing when cranking. Check that the crank angle sensor is installed properly.
OK: Approx. 5_ BTDC
OK

Check the following items.

D Check the ignition coil, spark plugs, spark plug cables.
D Check if the injectors are clogged.
D Check if foreign materials (water, alcohol, etc.) got into fuel.
D Check the compression pressure.
D Check the immobilizer system.

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 13D-42 MPI <4G63> ï Troubleshooting

INSPECTION PROCEDURE 6
Initial combustion but no complete combustion Probable cause
(starting impossible)
In such cases as the above, the cause is probably that the spark plugs are generating D Malfunction of the ignition system
sparks but the sparks are weak, or the initial mixture for starting is not appropriate. D Malfunction of the injector system
D Foreign materials in fuel
D Poor compression
D Malfunction of the engine-A/T-ECU

NG
Check battery voltage when cranking. Check the battery. (Refer to GROUP 54 ï Battery.)
OK: 8 V or higher
OK
YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
M.U.T.-II/III Actuator test Check the fuel pump system.
07 Fuel pump (Refer to P.13D-70) (Refer to P.13D-60, INSPECTION PROCEDURE 28.)
OK
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system.
21 Engine coolant temperature sensor (Refer to P.13D-66.) (RefertoP.13D-55,INSPECTIONPROCEDUREFORDIAGNOSIS
OK CODE 21.)
NG
M.U.T.-II/III Data list Check the ignition switch-ST and inhibitor switch system (Refer
18 Ignition switch-ST (Refer to P.13D-66.) to P.13D-62, INSPECTION PROCEDURE 29.)
OK

NG
Can any sound be heard from the injectors when cranking? Check the injector system, (Refer to P.13D-29, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
YES NG
Is starting good if the engine is cranked with the accelerator pedal Check ISC servo for Check the ISC servo sys-
slightly depressed? operation sound. tem. (Refer to P.13D-64,
(Refer to P.13D-102.) INSPECTION PROCE-
NO
DURE 32.)
OK

Clean the throttle valve area. (Refer to P.13D-90.)

NG
Check the ignition timing when cranking. Check that the crank angle sensor is installed properly.
OK: Approx. 5_BTDC
OK

Check the following items.

D Check the ignition coil, spark plugs, spark plug cables.
D Check if the injectors are clogged.
D Check the compression pressure.
D Check fuel lines for clogging.
D Check if foreign materials (water, alcohol, etc.) got into fuel.

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 MPI <4G63> ï Troubleshooting 13D-43
INSPECTION PROCEDURE 7
It takes too long time to start. (Incorrect starting) Probable cause
In cases such as the above, the cause is probably that the spark is weak and ignition D Malfunction of the ignition system
is difficult, the initial mixture for starting is not appropriate, or sufficient compression D Malfunction of the injector system
pressure is not being obtained. D Inappropriate gasoline use
D Poor compression

NG
Check battery voltage when cranking Check the battery. (Refer to GROUP 54 ï Battery.)
OK: 8 V or higher
OK
YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
M.U.T.-II/III Actuator test Check the fuel pump system.
07 Fuel pump (Refer to P.13D-70) (Refer to P.13D-60, INSPECTION PROCEDURE 28.)
OK
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system.
21 Engine coolant temperature sensor (Refer to P.13D-66.) (RefertoP.13D-20,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 21.)
OK
NG
M.U.T.-II/III Data list D Check the ignition switch-ST and inhibitor switch system.
18 Ignition switch-ST (Refer to P.13D-66.) (Refer to P.13D-62, INSPECTION PROCEDURE 29.)
OK

NG
Can any sound be heard from the injectors when cranking? Check the injector system. (Refer to P.13D-29, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
NG
Check the ignition timing when cranking. Check that the crank angle sensor is installed properly.
OK: Approx. 5_BTDC
OK

Check the following items.

D Check the ignition coil, spark plugs, spark plug cables.
D Check if the injectors are clogged.
D Check the compression pressure.
D Check if foreign materials (water, alcohol, etc.) got into fuel.

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 13D-44 MPI <4G63> ï Troubleshooting

INSPECTION PROCEDURE 8
Unstable idling (Rough idling, hunting) Probable cause
In cases as the above, the cause is probably that the ignition system, air/fuel mixture, D Malfunction of the ignition system
idle speed control (ISC) or compression pressure is defective. D Malfunction of the air-fuel ratio control system
Because the range of possible causes is broad, inspection is narrowed down to simple D Malfunction of the ISC system
items. D Malfunction of the purge control solenoid valve system
D Malfunction of the EGR solenoid valve system
D Poor compression
D Drawing air into exhaust system

YES
Were the battery terminals disconnected? After warming-up, let the engine run at idling for 10 minutes.
NO
YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
YES
Does idling speed fluctuate excessively? D Check the throttle valve area. (Refer to P.13D-90.)
NO

Check the trouble symptom.

NG

Inspect the intake of air into the air intake system.

D Broken intake manifold gasket
D Broken air intake hose
D Broken vacuum hose
D Positive crankcase ventilation valve does not operate.

NG
Check the ISC servo for operation sound. (Refer to P.13D-102.) Check the ISC servo system.
(Refer to P.13D-64, INSPECTION PROCEDURE 32.)
OK
NG
Check the injector for operation sound. Check the injector system. (Refer to P.13D-29, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
NG
M.U.T.-II/III Data list Check the throttle position sensor system. (Refer to P.13D-18,
14 Throttle position sensor (Refer to P.13D-66.) INSPECTION PROCEDURE FOR DIAGNOSIS CODE 14.)
OK
NG
M.U.T.-II/III Data list Check the intake air temperature sensor system.
13 Intake air temperature sensor (Refer to P.13D-66.) (RefertoP.13D-16,INSPECTIONPROCEDUREFORDIAGNOSIS
OK CODE 13.)
NG
M.U.T.-II/III Data list Check the barometric pressure sensor system. (Refer to P.13D-26,
25 Barometric pressure sensor (Refer to P.13D-66.) INSPECTION PROCEDURE FOR DIAGNOSIS CODE 25.)
OK
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system.
21 Engine coolant temperature sensor (Refer to P.13D-66.) (RefertoP.13D-20,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 21.)
OK
NG
M.U.T.-II/III Actuator test Check the purge control solenoid valve system. (Refer to P.13D-65,
08 Purge control solenoid valve INSPECTION PROCEDURE 33)
(Refer to P.13D-70.)
OK
NG
M.U.T.-II/III Actuator test Check the EGR control solenoid valve system.
10 EGR control solenoid valve (Refer to P.13D-70.) (Refer to P.13D-65, INSPECTION PROCEDURE 34.)

OK

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 MPI <4G63> ï Troubleshooting 13D-45
From the previous page
OK
NG
M.U.T.-II/III Data list Check the oxygen sensor (rear) system.
59 Oxygen sensor (rear) (RefertoP.13D-32,INSPECTIONPROCEDUREFORDIAGNOSIS
D Transmission: D range CODE 59.)
D Driving with throttle widely open
OK: 600 ï 1,000 mV
OK

NG
M.U.T.-II/III Data list Check the oxygen sensor (front) system.
11 Oxygen sensor (front) (RefertoP.13D-13,INSPECTIONPROCEDUREFORDIAGNOSIS
OK: 600 ï 1,000 mV during sudden racing CODE 11.)
OK
NG OK
M.U.T.-II/III Data list Check the fuel pressure. 1. Inspect the intake of
11 Oxygen sensor (front) (Refer to P.13D-92.) air into the air intake
OK: Changes between 0 ï 400 mV and 600 ï 1,000 mV during system.
idling D Broken intake man-
OK ifold gasket
NG D Broken vacuum hose
M.U.T.-II/III Data list Check the power steering D PCV valve does not
27 Power steering fluid pressure switch (Refer to P.13D-66.) fluid pressure switch sys- operate.
tem. (Refer to P.13D-63, D Broken airintakehose
OK 2. Check the injector for
INSPECTION PROCE-
DURE 30.) clog.

NG
M.U.T.-II/III Data list Check the A/C switch and A/C relay system.
28 A/C switch (Refer to P.13D-66.) (Refer to P.13D-63, INSPECTION PROCEDURE 31.)
OK
NG
M.U.T.-II/III Data list Adjust the basic idle speed. (Refer to P.13D-91.)
45 ISC servo position (Refer to P.13D-66.)
OK
NG
Check the ignition timing. Check that the crank angle sensor is installed properly.
(Refer to GROUP 11E ï On-vehicle Service.)
OK

Check the following items.

D Check the ignition coil, spark plugs, spark plug cables.
D Check the purge control system.
D Check the EGR control system.
D Check the compression pressure.
D Check if foreign materials (water, alcohol, etc.) got into fuel.

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 13D-46 MPI <4G63> ï Troubleshooting

INSPECTION PROCEDURE 9
Idling speed is high. (Improper idling speed) Probable cause
In such cases as the above, the cause is probably that the intake air volume during D Malfunction of the ISC servo system
idling is too great. D Malfunction of the throttle body

YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
Check the ISC servo for operation sound. (Refer to P.13D-102.) Check the ISC servo system.
(Refer to P.13D-64, INSPECTION PROCEDURE 32.)
OK
NG
M.U.T.-II/III Data list Check the throttle position sensor system.
14 Throttle position sensor (Refer to P.13D-66.) (RefertoP.13D-18,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 14.)
OK
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system.
21 Engine coolant temperature sensor (Refer to P.13D-66.) (RefertoP.13D-20,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 21.)
OK

NG
M.U.T.-II/III Data list Check the A/C switch and A/C relay system.
28 A/C switch (Refer to P.13D-66.) (Refer to P.13D-63, INSPECTION PROCEDURE 31.)
OK

Basic idle speed adjustment (Refer to P.13D-91.)

NG
Check the trouble symptom. Clean the throttle valve area. (Refer to P.13D-90.)

INSPECTION PROCEDURE 10
Idling speed is low. (Improper idling speed) Probable cause
In cases such as the above, the cause is probably that the intake air volume during D Malfunction of the ISC servo system
idling is too small. D Malfunction of the throttle body

YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
Check the ISC servo for operation sound. (Refer to P.13D-102.) Check the ISC servo system.
(Refer to P.13D-64, INSPECTION PROCEDURE 32.)
OK
NG
M.U.T.-II/III Data list Check the throttle position sensor system.
14 Throttle position sensor (Refer to P.13D-66.) (RefertoP.13D-18,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 14.)
OK
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system.
21 Engine coolant temperature sensor (Refer to P.13D-66.) (RefertoP.13D-20,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 21.)
OK

Basic idle speed adjustment (Refer to P.13D-91.)

NG
Check the trouble symptom. Clean the throttle valve area. (Refer to P.13D-90.)

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 MPI <4G63> ï Troubleshooting 13D-47
INSPECTION PROCEDURE 11
When the engine is cold, it stalls at idling. (Die out) Probable cause
In such cases as the above, the cause is probablythatthe air/fuelmixture isinappropriate D Malfunction of the ISC servo system
when the engine is cold, or that the intake air volume is insufficient. D Malfunction of the throttle body
D Malfunction of the injector system
D Malfunction of the ignition system

YES
Were the battery terminals disconnected? After warming-up, let the engine run at idling for 10 minutes.
NO
YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
YES
Does the engine stall right after the accelerator pedal is released? Clean the throttle valve area. (Refer to P.13D-90.)
NO
NO
Is engine-idling stable after the warming-up? Check if the unstable idling (Rough idling, hunting).
(Refer to P.13D-44, INSPECTION PROCEDURE 8.)
YES

NG
Check the ISC servo for operation sound. (Refer to P.13D-102.) Check the ISC servo system.
(Refer to P.13D-64, INSPECTION PROCEDURE 32.)
OK

NG
Check the injector for operation sound. Check the injector system. (Refer to P.13D-29, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK

NG
M.U.T.-II/III Data list Check the throttle position sensor system. (Refer to P.13D-18,
14 Throttle position sensor (Refer to P.13D-66.) INSPECTION PROCEDURE FOR DIAGNOSIS CODE 14.)
OK
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system.
21 Engine coolant temperature sensor (Refer to P.13D-66.) (RefertoP.13D-20,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 21.)
OK
NG
M.U.T.-II/III Actuator test Check the EGR control solenoid valve system.
10 EGR control solenoid valve (Refer to P.13D-70.) (Refer to P.13D-65, INSPECTION PROCEDURE 34.)
OK

Check the fuel pressure. (Refer to P.13D-92.)

OK
NG
Check the ignition timing. Check that the crank angle sensor is installed properly.
(Refer to GROUP 11C ï On-vehicle Service.)
OK

Check the following items.

D Check the ignition coil, spark plugs, spark plug cables.
D Check the compression pressure.
D Check the engine oil viscosity.

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 13D-48 MPI <4G63> ï Troubleshooting

INSPECTION PROCEDURE 12
When the engine is hot, it stalls at idling. (Die out) Probable cause
In such cases as the above, the cause is probably that ignition system, air/fuel mixture, D Malfunction of the ignition system
idle speed control (ISC) or compression pressure is defective. D Malfunction of the air-fuel ratio control system
In addition, if the engine suddenly stalls, the cause may also be a defective connector D Malfunction of the ISC system
contact. D Drawing air into intake system
D Improper connector contact

YES
Were the battery terminals disconnected? After warming-up, let the engine run at idling for 10 minutes.
NO
YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
Check the ISC servo for operation sound. (Refer to P.13D-102.) Check the ISC servo system.
(Refer to P.13D-64, INSPECTION PROCEDURE 32.)
OK
NG
Check the injector for operation sound. Check the injector system. (Refer to P.13D-29, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
YES
Does the engine stall right after the accelerator pedal is released? D Clean the throttle valve area. (Refer to P.13D-90.)
NO
NO
Does the engine stall easily again? While carrying out an intermittent malfunction simulation test (Refer
to GROUP 00 ï Points to Note for Intermittent Malfunctions.), check
YES for sudden changes in the signals shown below.
D Crank angle sensor signal D Primary and secondary
D Injector drive signal ignition signal
D Fuel pump drive signal
D Engine-A/T-ECU power
supply voltage

NG
M.U.T.-II/III Data list Check the throttle position sensor system. (Refer to P.13D-18,
14 Throttle position sensor (Refer to P.13D-66.) INSPECTION PROCEDURE FOR DIAGNOSIS CODE 14.)
OK
NG
M.U.T.-II/III Data list Check the intake air temperature sensor system.
13 Intake air temperature sensor (Refer to P.13D-66.) (RefertoP.13D-16,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 13.)
OK
NG
M.U.T.-II/III Data list Check the barometric pressure sensor system.
25 Barometric pressure sensor (Refer to P.13D-66.) (RefertoP.13D-26,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 25.)
OK
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system.
21 Engine coolant temperature sensor (Refer to P.13D-66.) (RefertoP.13D-20,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 21.)
OK
NG
M.U.T.-II/III Actuator test Check the EGR control solenoid valve system.
10 EGR control solenoid valve (Refer to P.13D-70.) (Refer to P.13D-65, INSPECTION PROCEDURE 34.)
OK
NG
M.U.T.-II/III Data list Check the oxygen sensor (rear) system.
59 Oxygen sensor (rear) (RefertoP.13D-32,INSPECTIONPROCEDUREFORDIAGNOSIS
D Transmission: D range CODE 59.)
D Driving with throttle widely open
OK: 600 ï 1,000 mV
OK
NG
M.U.T.-II/III Data list Check the oxygen sensor (front) system.
11 Oxygen sensor (front) (RefertoP.13D-13,INSPECTIONPROCEDUREFORDIAGNOSIS
OK: 600 ï 1,000 mV during sudden racing CODE 11.)
OK

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 MPI <4G63> ï Troubleshooting 13D-49
From the previous page
OK
NG OK
M.U.T.-II/III Data list Check the fuel pressure. 1. Inspect the intake of
11 Oxygen sensor (front) (Refer to P.13D-92.) air into the air intake
OK: Changes between 0 ï 400 mV and 600 ï 1,000 mV during system.
idling D Broken intake man-
OK ifold gasket
D Broken vacuum hose
NG
M.U.T.-II/III Data list Check the power steering D PCV valve does not
27 Power steering fluid pressure switch (Refer to P.13D-66.) fluid pressure switch sys- operate.
tem. (Refer to P.13D-63, D Broken airintakehose
OK 2. Check the injector for
INSPECTION PROCE-
DURE 30.) clog.

NG
M.U.T.-II/III Data list Check the A/C switch and A/C relay system.
28 A/C switch (Refer to P.13D-66.) (Refer to P.13D-63, INSPECTION PROCEDURE 31.)
OK
NG
M.U.T.-II/III Data list Adjust the basic idle speed. (Refer to P.13D-91.)
45 ISC servo position (Refer to P.13D-66.)
OK
NG
Check the ignition timing. Check that the crank angle sensor is installed properly.
(Refer to GROUP 11C ï On-vehicle Service.)
OK

Check the following items.

D Check the ignition coil, spark plugs, spark plug cables.
D Check if the injectors are clogged.
D Check the compression pressure.
D Check if foreign materials (water, alcohol, etc.) got into fuel.

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 13D-50 MPI <4G63> ï Troubleshooting

INSPECTION PROCEDURE 13
The engine stalls when starting the car. (Pass out) Probable cause
In cases such as the above, the cause is probably misfiring due to a weak spark, D Drawing air into intake system
or an inappropriate air/fuel mixture when the accelerator pedal is depressed. D Malfunction of the ignition system

YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
M.U.T.-II/III Actuator test Check the EGR control solenoid valve system.
10 EGR control solenoid valve (Refer to P.13D-70.) (Refer to P.13D-65, INSPECTION PROCEDURE 34.)
OK

Check the following items.

D Check the ignition coil, spark plugs, spark plug cables.
D Check if air was drawn into the intake system.
Broken intake manifold gasket
Broken or disconnected vacuum hose
Improper operation of the PCV valve
Broken air intake hose

INSPECTION PROCEDURE 14
The engine stalls when decelerating. Probable cause
In cases such as the above, the cause is probably that the intake airvolume is insufficient D Malfunction of the ISC system
due to a defective idle speed control (ISC) servo system.

YES
Were the battery terminals disconnected? After warming-up, let the engine run at idling for 10 minutes.
NO
YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
M.U.T.-II/III Data list Check the throttle position sensor system. (Refer to P.13D-18,
14 Throttle position sensor (Refer to P.13D-66.) INSPECTION PROCEDURE FOR DIAGNOSIS CODE 14.)
OK

YES
M.U.T.-II/III Data list Check the vehicle speed signal system. (Refer to P.13D-25, IN-
45 ISC servo position SPECTION PROCEDURE FOR DIAGNOSIS CODE 24.)
D Is the idle speed control (ISC) servo position drops to 0ï2
steps when decelerating (engine r/min less than 1,000)?
NO
NG
M.U.T.-II/III Actuator test Check the EGR control solenoid valve system.
10 EGR control solenoid valve (Refer to P.13D-70.) (Refer to P.13D-65, INSPECTION PROCEDURE 34.)
OK

Check the following items.

D Check the ignition coil, spark plugs, spark plug cables.
D Clean the throttle valve area.

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 MPI <4G63> ï Troubleshooting 13D-51
INSPECTION PROCEDURE 15
Hesitation, sag or stumble Probable cause
In cases such as the above, the cause is probably that ignition system, air/fuel mixture D Malfunction of the ignition system
or compression pressure is defective. D Malfunction of the air-fuel ratio control system
D Malfunction of the fuel supply system
D Malfunction of the EGR control solenoid valve system
D Poor compression

YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
Check the injectors for operation sound. Check the injector system. (Refer to P.13D-29, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
NG
Check the ignition timing. Check that the crank angle sensor is installed properly.
(Refer to GROUP 11C ï On-vehicle Service.)
OK
NG
M.U.T.-II/III Data list Check the intake air temperature sensor system.
13 Intake air temperature sensor (Refer to P.13D-66.) (RefertoP.13D-16,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 13.)
OK
NG
M.U.T.-II/III Data list Check the barometric pressure sensor system.
25 barometric pressure sensor (Refer to P.13D-66.) (RefertoP.13D-26,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 25.)
OK
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system.
21 Engine coolant temperature sensor (Refer to P.13D-66.) (RefertoP.13D-20,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 21.)
OK
NG
M.U.T.-II/III Data list Check the throttle position sensor system. (Refer to P.13D-18,
14 Throttle position sensor (Refer to P.13D-66.) INSPECTION PROCEDURE FOR DIAGNOSIS CODE 14.)
OK
NG
M.U.T.-II/III Actuator test Check the EGR control solenoid valve system.
10 EGR control solenoid valve (Refer to P.13D-70.) (Refer to P.13D-65, INSPECTION PROCEDURE 34.)
OK
NG
M.U.T.-II/III Data list Check the oxygen sensor (rear) system.
59 Oxygen sensor (rear) (RefertoP.13D-32,INSPECTIONPROCEDUREFORDIAGNOSIS
D Transmission: D range CODE 59.)
D Driving with throttle widely open
OK: 600 ï 1,000 mV
OK
NG
M.U.T.-II/III Data list Check the oxygen sensor (front) system.
11 Oxygen sensor (front) (RefertoP.13D-13,INSPECTIONPROCEDUREFORDIAGNOSIS
OK: 600 ï 1,000 mV during sudden racing CODE 11.)
OK

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 13D-52 MPI <4G63> ï Troubleshooting

From the previous page

OK
NG OK
M.U.T.-II/III Data list Check the fuel pressure. 1. Inspect the intake of
11 Oxygen sensor (front) (Refer to P.13D-92.) air into the air intake
OK: Changes between 0 ï 400 mV and 600 ï 1,000 mV during system.
idling D Broken intake man-
ifold gasket
OK
D Broken vacuum hose
D PCV valve does not
Check the fuel pressure. (Refer to P.13D-92.)
operate.
OK D Broken airintakehose
2. Check the injector for
clog.

Check the following items.

D Check the ignition coil, spark plugs, spark plug cables.
D Check the EGR control system.
D Check the compression pressure.
D Check the fuel filter or fuel line for clogging.

INSPECTION PROCEDURE 16
The feeling of impact or vibration when accelerating Probable cause
In cases such as the above, the cause is probably that there is an ignition leak D Malfunction of the ignition system
accompanying the increase in the spark plug demand voltage during acceleration.

YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO

Check the following items.

D Check the ignition coil, spark plugs, spark plug cables.
D Check for occurrence of ignition leak.

INSPECTION PROCEDURE 17
The feeling of impact or vibration when decelerating. Probable cause
Malfunction of the ISC system is suspected. D Malfunction of the ISC system

YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
Check the ISC servo for operation sound. (Refer to P.13D-102.) Check the ISC servo system.
(Refer to P.13D-64, INSPECTION PROCEDURE 32.)
OK
NG
M.U.T.-II/III Data list Check the throttle position sensor system. (Refer to P.13D-18,
14 Throttle position sensor (Refer to P.13D-66.) INSPECTION PROCEDURE FOR DIAGNOSIS CODE 14.)
OK

Clean the throttle valve area. (Refer to P.13D-90.)

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 MPI <4G63> ï Troubleshooting 13D-53
INSPECTION PROCEDURE 18
Poor acceleration Probable cause
Defective ignition system, abnormal air-fuel ratio, poor compression pressure, etc. D Malfunction of the ignition system
are suspected. D Malfunction of the air-fuel ratio control system
D Malfunction of the fuel supply system
D Poor compression pressure
D Clogged exhaust system

YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
Check the injectors for operation sound. Check the injector system. (Refer to P.13D-29, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
NG
Check the ignition timing. Check that the crank angle sensor is installed properly.
(Refer to GROUP 11C ï On-vehicle Service.)
OK
NG
M.U.T.-II/III Data list Check the intake air temperature sensor system.
13 Intake air temperature sensor (Refer to P.13D-66.) (RefertoP.13D-16,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 13.)
OK
NG
M.U.T.-II/III Data list Check the barometric pressure sensor system.
25 Barometric pressure sensor (Refer to P.13D-66.) (RefertoP.13D-26,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 25.)
OK
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system.
21 Engine coolant temperature sensor (Refer to P.13D-66.) (RefertoP.13D-20,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 21.)
OK
NG
M.U.T.-II/III Data list Check the throttle position sensor system. (Refer to P.13D-18,
14 Throttle position sensor (Refer to P.13D-66.) INSPECTION PROCEDURE FOR DIAGNOSIS CODE 14.)
OK
NG
M.U.T.-II/III Actuator test Check the EGR control solenoid valve system.
10 EGR control solenoid valve (Refer to P.13D-70.) (Refer to P.13D-65, INSPECTION PROCEDURE 34.)
OK
NG
M.U.T.-II/III Data list Check the oxygen sensor (rear) system.
59 Oxygen sensor (rear) (RefertoP.13D-32,INSPECTIONPROCEDUREFORDIAGNOSIS
D Transmission: D range CODE 59.)
D Driving with throttle widely open
OK: 600 ï 1,000 mV
OK

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 13D-54 MPI <4G63> ï Troubleshooting

From the previous page

OK
NG
M.U.T.-II/III Data list Check the oxygen sensor (front) system.
11 Oxygen sensor (front) (RefertoP.13D-13,INSPECTIONPROCEDUREFORDIAGNOSIS
OK: 600 ï 1,000 mV during sudden racing CODE 11.)
OK
NG OK
M.U.T.-II/III Data list Check the fuel pressure. 1. Inspect the intake of
11 Oxygen sensor (front) (Refer to P.13D-92.) air into the air intake
OK: Changes between 0 ï 400 mV and 600 ï 1,000 mV during system.
idling D Broken intake man-
ifold gasket
OK
D Broken vacuum hose
Check the fuel pressure. (Refer to P.13D-92.) D PCV valve does not
operate.
OK D Broken airintakehose
2. Check the injector for
clog.

Check the following items.

D Check the ignition coil, spark plugs, spark plug cables.
D Check the compression pressure.
D Check the fuel filter or fuel line for clogging.
D Broken air intake hose
D Clogged air cleaner

INSPECTION PROCEDURE 19
Surge Probable cause
Defective ignition system, abnormal air-fuel ratio, etc. are suspected. D Malfunction of the ignition system
D Malfunction of the air-fuel ratio control system
D Malfunction of the EGR control solenoid valve system

YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
Check the injectors for operation sound. Check the injector system. (Refer to P.13D-29, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
OK
NG
Check the ignition timing. Check that the crank angle sensor is installed properly.
(Refer to GROUP 11E ï On-vehicle Service.)
OK
NG
M.U.T.-II/III Data list Checktheintakeairtemperaturesensor system. (RefertoP.13D-16,
13 Intake air temperature sensor (Refer to P.13D-66.) INSPECTION PROCEDURE FOR DIAGNOSIS CODE 13.)
OK
NG
M.U.T.-II/III Data list Check the barometric pressure sensor system. (Refer to P.13D-26,
25 Barometric pressure sensor (Refer to P.13D-66.) INSPECTION PROCEDURE FOR DIAGNOSIS CODE 25.)
OK
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system.
21 Engine coolant temperature sensor (Refer to P.13D-66.) (RefertoP.13D-20,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 21.)
OK
NG
M.U.T.-II/III Data list Check the throttle position sensor system.
14 Throttle position sensor (Refer to P.13D-66.) (RefertoP.13D-18,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 14.)
OK
NG
M.U.T.-II/III Actuator test Check the EGR control solenoid valve system.
10 EGR control solenoid valve (Refer to P.13D-70.) (Refer to P.13D-65, INSPECTION PROCEDURE 34.)
OK

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 MPI <4G63> ï Troubleshooting 13D-55
From the previous page
OK
NG
M.U.T.-II/III Data list Check the oxygen sensor (rear) system.
59 Oxygen sensor (rear) (RefertoP.13D-32,INSPECTIONPROCEDUREFORDIAGNOSIS
D Transmission: D range CODE 59.)
D Driving with throttle widely open
OK: 600 ï 1,000 mV
OK
NG
M.U.T.-II/III Data list Check the oxygen sensor (front) system.
11 Oxygen sensor (front) (RefertoP.13D-13,INSPECTIONPROCEDUREFORDIAGNOSIS
OK: 600 ï 1,000 mV during sudden racing CODE 11.)
OK
NG OK
M.U.T.-II/III Data list Check the fuel pressure. 1. Inspect the intake of
11 Oxygen sensor (front) (Refer to P.13D-92.) air into the air intake
OK: Changes between 0 ï 400 mV and 600 ï 1,000 mV during system.
idling D Broken intake man-
ifold gasket
OK
D Broken vacuum hose
Check the fuel pressure. (Refer to P.13D-92.) D PCV valve does not
operate.
OK D Broken airintakehose
2. Check the injector for
clog.

Check the following items.

D Check the ignition coil, spark plugs, spark plug cables.
D Check the EGR control system.

INSPECTION PROCEDURE 20
Knocking Probable cause
In cases as the above, the cause is probably that the detonation control is defective D Inappropriate heat value of the spark plug
or the heat value of the spark plug is inappropriate. D Defective detonation sensor

YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NO
Does knocking occur when driving with the detonation sensor Check the detonation sensor system. (Refer to P.13D-28, INSPEC-
connector disconnected? At this time, use the M.U.T.-II/III to check TION PROCEDURE FOR DIAGNOSIS CODE 31.)
if the timing is retarded compared to when the detonation sensor
connector is disconnected.
YES

Check the following items.

D Spark plugs
D Check if foreign materials (water, alcohol, etc.) got into fuel.

INSPECTION PROCEDURE 21
Dieseling Probable cause
Fuel leakage from injectors is suspected. D Fuel leakage from injectors

Check the injectors for fuel leakage.

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 13D-56 MPI <4G63> ï Troubleshooting

INSPECTION PROCEDURE 22
Too high CO and HC concentration when idling Probable cause
Abnormal air-fuel ratio is suspected. D Malfunction of the air-fuel ratio control system
D Deteriorated catalyst

YES
M.U.T.-II/III Self-Diag code Refer to P.13D-12, INSPECTION CHART FOR DIAGNOSIS
Are diagnosis codes displayed? CODES.
NO
NG
Check the ignition timing. Check that the crank angle sensor is installed properly.
(Refer to GROUP 11C ï On-vehicle Service.)
OK
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system.
21 Engine coolant temperature sensor. (Refer to P.13D-66.) (RefertoP.13D-20,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 21.)
OK
NG
M.U.T.-II/III Data list Check the intake air temperature sensor system.
13 Intake air temperature sensor (Refer to P.13D-66.) (RefertoP.13D-16,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 13.)
OK
NG
M.U.T.-II/III Data list Check the barometric pressure sensor system.
25 Barometric pressure sensor (Refer to P.13D-66.) (RefertoP.13D-26,INSPECTIONPROCEDUREFORDIAGNOSIS
CODE 25.)
OK
NG
M.U.T.-II/III Data list Check the oxygen sensor (rear) system.
59 Oxygen sensor (rear) (RefertoP.13D-32,INSPECTIONPROCEDUREFORDIAGNOSIS
D Transmission: D range CODE 59.)
D Driving with throttle widely open
OK: 600 ï 1,000 mV
OK
NG
M.U.T.-II/III Data list Check the oxygen sensor (front) system.
11 Oxygen sensor (front) (RefertoP.13D-13,INSPECTIONPROCEDUREFORDIAGNOSIS
OK: 600 ï 1,000 mV when racing suddenly. CODE 11.)
OK
OK
M.U.T.-II/III Data list Replace the oxygen sensor.
11 Oxygen sensor (front)
OK: Repeat 0 ï 400 mV and 600 ï 1,000 mV alternately when
idling.
Check the trouble symptom.
NG NG
Check the fuel pressure. (Refer to P.13D-92.)
OK

Check the following items.

D Check the injectors for operation sound.
D Check the injectors for fuel leakage.
D Check the ignition coil, spark plugs, spark plug cables.
D Check the compression pressure.
D Check the positive crankcase ventilation system.
D Check the purge control system.
D Check the EGR control system.

Check the trouble symptom.

NG

Replace the catalytic converter.

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 MPI <4G63> ï Troubleshooting 13D-57
INSPECTION PROCEDURE 23
Low alternator output voltage (approx. 12.3 V) Probable cause
The alternator may be defective, or malfunctions, which are listed in the right column, D Malfunction of the charging system
may be suspected. (Refer to GROUP 16 ï Charging System.)
D Short circuit in harness between alternator G terminal
and engine-A/T-ECU
D Malfunction of the engine-A/T-ECU

NG NG
Measureatthealternatorconnectorside Measure at the alternator connector. Check the harness wire between the
B-26. B-26 alternator and the engine-A/T-ECU con-
D Connect the connector. D Disconnect the connector, and nector, and repair if necessary.
(Test harness: MB991519) measure at the harness side.
D Voltage between 1 (black clip) and D Disconnect the engine-A/T-ECU
earth connector.
(Engine: Idling) D Continuity between 1 and earth
(Radiator fan: Not operating) OK: No continuity
(Head lamp: OFF o ON)
OK
(Stop lamp: OFF o ON)
(Rear defogger switch: OFF o ON) NG
Check the following connectors: Repair
OK: Voltage rises by 0.2 ï 3.5 V. B-18, C-122
OK OK
NG
Check the alternator. (Refer to GROUP Check the trouble symptom. Replace the engine-A/T-ECU.
16 ï Charging System.)

INSPECTION PROCEDURE 24
Idling speed is improper when A/C is operating Probable cause
If the engine-A/T-ECU detects that the air conditioner is on, it activates the idle D Malfunction of the A/C control system
speed control (ISC) servo to control idle-up operation. D Improper connector contact, open circuit or
The automatic compressor-ECU judges if the load caused by air conditioner short-circuited harness wire
operation is high or low, and converts it to voltage signal (high or low voltage) D Malfunction of the engine-A/T-ECU
and inputs the signal to the engine-A/T-ECU.
Based on this voltage signal, the engine-A/T-ECU controls the idle-up speed (for
high or low load).

OK
Measure at the engine-A/T-ECU connector C-124. Check the following connector:
D Connect the connector. C-124
D Voltage between 61 and earth (Engine: at idle, outside air
OK NG
temperature: 25_C or more)
OK: 0 ï 3 V [When A/C is MAX. COOL condition (when
the load by A/C is high)] Repair
System voltage [When A/C is MAX. HOT condition
(when the load by A/C is low)] Check the trouble symptom.
NG NG

Check the A/C system. (Refer to GROUP 55 ï On-vehicle Service.) Replace the engine-A/T-ECU.

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 13D-58 MPI <4G63> ï Troubleshooting

INSPECTION PROCEDURE 25
Fans (radiator fan, A/C condenser fan) are inoperative. Probable cause
The engine-A/T-ECU sends a duty signal to the fan controller according to engine D Malfunction of the fan motor relay
coolant temperature, vehicle speed, or A/C switch. D Malfunction of the fan motor
The fan controller controls radiator fan and condenser fan speeds, based on this D Malfunction of the fan controller
signal. (The closer the terminal voltage comes to 5 V, the higher the fan speedbecomes.) D Open or short circuit, or poor connector contact
D Malfunction of the engine-A/T-ECU

NG
Measure at the engine-A/T-ECU connector C-122. Check the harness wire between the engine-A/T-ECU and fan con-
D Disconnect the connector, measure at the harness side. troller.
D Voltage between terminal 18 and earth OK NG
(Ignition switch: ON)
OK: 4.8 ï 5.2 V (The fan runs at high speed.) Repair
D Earth terminal 18.
(Ignition switch: ON)
Check the radiator fan and condenser fan circuit. (Refer to GROUP
OK: The fan stops.
14 ï Troubleshooting.)
OK
NG
Check the following connector: C-122 Repair
OK

Check the trouble symptom.

NG
NG
M.U.T.-II/III Data list Check the engine coolant temperature sensor system. (Refer to
21 Engine coolant temperature sensor P.13D-20, INSPECTION PROCEDURE FOR DIAGNOSIS DODE
OK: After the engine has been warmed up, the engine coolant 21.)
temperature during idling is identical to the M.U.T.-II/III read-
ing.
OK
NG
Check the thermostat. Replace
OK

Replace the engine-A/T-ECU.

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 MPI <4G63> ï Troubleshooting 13D-59
INSPECTION PROCEDURE 26
Check the engine-A/T-ECU power supply and earth circuit.

(1) NG NG
Measure the engine-A/T-ECU connectors, C-124, C-126. Check the following Repair
D Disconnect the connector and measure at the harness side connectors: C-14,
(1) Voltage between 98 and earth (Ignition switch: ON) C-209, Cï210
OK: System voltage (2), (3) NG OK
(2) Voltage between 49 and earth
OK: System voltage Check the trouble symptom.
(3) Voltage between 41, 47 and earth (4) NG
OK: System voltage (when the terminal 49 is earthed) OK
(4) Continuity between 42, 48 and earth NG
OK: Continuity (5) Check the harness wire Repair
(5) Voltage between 66 and earth NG betweenengine-A/T-ECU
OK: System voltage and ignition switch con-
nector.
OK
OK
NG Check the ignition switch.
Check the following Repair
(Refer to GROUP 54 ï Ignition Switch and Immobilizer System.)
connectors:
C-124, C-126
NG
OK Check the following Repair
connectors: A-13,
Check the trouble symptom. B-16X, C-12
NG OK
Replace the engine-A/T-ECU. Check the trouble symptoms.
NG

Check the harness wire between engine-A/T-ECU and control relay

connector, and repair if necessary.

Check the harness wire between engine-A/T-ECU and battery,

and repair if necessary. Check the harness wire between engine-A/T-ECU and earth, and
repair if necessary.

INSPECTION PROCEDURE 27
Power supply system and ignition switch-IG system Probable cause
When an ignition switch ON signal is input to the engine-A/T-ECU, the engine-A/T-ECU D Malfunction of the ignition switch
turns the engine control relay ON. This causes battery voltage to be supplied to the D Malfunction of the engine control relay
engine-A/T-ECU, injectors and air flow sensor. D Improper connector contact, open circuit or
short-circuited harness wire
D Disconnected engine-A/T-ECU earth wire
D Malfunction of the engine-A/T-ECU

NG
Check the engine control relay. (Refer to P.13D-96.) Replace
OK
NG NG
Measure at the engine control relay connector B-16X. Check the following Repair
D Disconnect the connector, and measure at the harness side. connector: A-13
D Voltage between 3, 4 and earth
OK
OK: System voltage
OK Check the trouble symptom.
NG
Check the engine-A/T-ECU power supply and earth circuit.
(Refer to P.13D-59, INSPECTION PROCEDURE 26.) Checktheharnesswirebetweenbatteryandcontrolrelayconnector,
and repair if necessary.

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 13D-60 MPI <4G63> ï Troubleshooting

INSPECTION PROCEDURE 28
Fuel pump system Probable cause
Engine-A/T-ECU turns fuel pump relay ON to supply drive voltage to fuel pump while D Malfunction of the fuel pump relay (1)
engine is cranked and rotated. D Malfunction of the fuel pump relay (2)
D Malfunction of the fuel pump
D Improper connector contact, open circuit or
short-circuited harness wire
D Malfunction of the engine-A/T-ECU

OK
M.U.T.-II/III Actuator test Normal
07 Fuel pump (Refer to P.13D-70.)
NG
NG
Check fuel pump relay (1). Replace
(Refer to P.13D-96.)
OK
NG
Check fuel pump relay (2). Replace
(Refer to P.13D-96.)
OK
(1) NG NG
Measure at connector C-222 of fuel Check the following connector: Repair
pump relay (1) C-210
D Disconnect the connector to
measure at the harness side OK
(1) Voltage of terminal No. 1 ï earth NG
Check the trouble symptom. Check harness from fuel pump relay
(Ignition switch: ON) (1) to ignition switch.
OK: System voltage (2) NG
(2) Voltage of terminal No. 2 ï earth Check the following connectors: NG OK NG
Repair
OK: System voltage C-209, C-27
(3) Continuity of terminal No. 4 ï earth Repair
OK: Continuity OK
Check ignitionswitch. (Referto GROUP
Check and repair harness from fuel 54A ï Ignition Switch.)
pump relay (1) to battery.

(3) NG NG
Check the following connector: Repair
C-212
OK
Check and repair harness from fuel
OK
pump relay (1) to earth.

(1) NG NG
Measure at connector C-220 of fuel Check the following connector: Repair
pump relay (2) C-210
D Disconnect the connector to
measure at the harness side. OK
NG
D Ignition switch: ON Check the trouble symptom. Check harness from fuel pump relay
(1) Voltage of terminal No.1 ï earth (2) to ignition switch.
OK: System voltage (2) NG
(2) Voltage of terminal No.3 ï earth OK NG
Check the following connector:
OK: System voltage C-222 Repair
OK
OK NG
Check ignition switch. (Refer to GROUP
To the next page. Repair 54A ï Ignition Switch.)

Check and repair harness from fuel

pump relay (1) to fuel pump relay (2).

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 MPI <4G63> ï Troubleshooting 13D-61
From the previous page.
OK
NG NG
Measure at the C-122 engine-A/T-ECU Check the following connectors: Repair
connector. C-14, C-212, Cï220
D Disconnect the connector to
measure at the harness side OK
D Voltage of terminal No. 21 ï earth NG
Check the trouble symptom. Check and repair harness from fuel
D Ignition switch: ON
OK: System voltage pump relay (2) to engine-A/T-ECU

OK
OK NG
Measure at connector C-122 of engine- Check the following connector: Repair
A/T-ECU C-122
D Disconnect the connector to
measure at the harness side OK
D Terminal No. 21 ï earth short circuit NG
D Ignition switch: ON Check the trouble symptom. Replace the engine-A/T-ECU.
OK: Fuel pump is operated
(operating noise audible)
NG
(1) NG NG
Measure at connector D-16 of fuel pump Check the following connectors: Repair
D Disconnect the connector to D-18, C-215, C-220
measure at the harness side OK
(1) Voltage of terminal No. 5 ï earth NG
(Ignition switch: ON) Check the trouble symptom. Check and repair harness from fuel
OK: System voltage pump relay (2) to fuel pump.
(2) Continuity of terminal No. 4 ï earth (2) NG NG
OK: Continuity Check the following connector: Repair
D-16
OK
NG
OK Check the trouble symptom. Check and repair harness from fuel
pump to earth.

NG
Check the following connectors: Replace
D-16, D-18, C-215, C-220
OK

Check the trouble symptom.

NG

Replace the fuel pump.

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 13D-62 MPI <4G63> ï Troubleshooting

INSPECTION PROCEDURE 29
Ignition switch-ST and inhibitor switch system Probable cause
D The ignition switch-ST inputs a HIGH signal to the engine-A/T-ECU while the D Malfunction of the ignition switch
engine is cranking. D Malfunction of the inhibitor switch
The engine-A/T-ECU controls fuel injection, etc. during starting based on this input. D Improper connector contact, open circuit or
D The inhibitor switch inputs the condition of the select lever, i.e. whether it is in short-circuited harness wire
P or N range or in some other range, to the engine-A/T-ECU. D Malfunction of the engine-A/T-ECU.
The engine-A/T-ECU controls the idle speed control (ISC) servo based on this
input.

NG
M.U.T.-II/III Data list Check the inhibitor switch system
Check the 61 Inhibitor switch data list (Refer to GROUP 23A ï On-vehicle Ser-
of automatic transmission system. vice.)
(Refer to GROUP 23A ï Troubleshoot-
ing.)
OK
NG
Check the inhibitor switch Replace
D Continuity between the terminal 9
and terminal 10
(Refer to GROUP 23A ï
Troubleshooting.)
OK
NG NG
Measure at the inhibitor switch connec- Check the following connector: Repair
tor B-20. C-14
D Disconnect the connector, and
measure at the harness side. OK
D Voltage between 10 and earth Check the trouble symptom.
(Ignition switch: START)
OK: System voltage NG
OK
OK Check the harness wire between the Check the ignition switch (Refer to
inhibitor switch and ignition switch. GROUP 54 ï Ignition Switch and
Immobilizer system.)
NG
Repair
NG NG
Measure at the engine-A/T-ECU con- Check the following connector: Repair
nector C-124. B-20
D Disconnect the connector, and
OK
measure at the harness side.
D Voltage between 58 and earth NG
Check the trouble symptom. Check the harness wire between the
(Selector lever: P or N range) inhibitor switch and engine-A/T-ECU,
(Ignition switch: START) and repair if necessary.
OK: System voltage
OK

Check the following connector: NG

Replace
C-124
OK

Check the trouble symptom.

NG

Replace the engine-A/T-ECU.

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 MPI <4G63> ï Troubleshooting 13D-63
INSPECTION PROCEDURE 30
Power steering fluid pressure switch system Probable cause
The presence or absence of power steering load is input to the engine-A/T-ECU. D Malfunction of the power steering fluid pressure switch
The engine-A/T-ECU controls the idle speed control (ISC) servo based on this input. D Improper connector contact, open circuit or
short-circuited harness wire
D Malfunction of the engine-A/T-ECU

NG
Check the power steering fluid pressure switch. Replace
(Refer to GROUP 37A ï On-vehicle Service.)
OK
NG NG
Measure at the power steering fluid pressure switch connector Check the following Repair
B-115. connector: C-124
D Disconnect the connector, and measure at the harness side.
OK
D Voltage between 1 and earth (Ignition switch: ON)
OK: System voltage Check the trouble symptom.
OK NG
NG NG
Check the following Repair Check harness wire be- Repair
connector: B-115 tween engine-A/T-ECU
OK and power steering fluid
pressure switch connec-
Check the trouble symptom. tor.
NG OK

Replace the engine-A/T-ECU. Replace the engine-A/T-ECU.

INSPECTION PROCEDURE 31
A/C switch and A/C relay system Probable cause
When an A/C ON signal is input to the engine-A/T-ECU, the engine-A/T-ECU carries D Malfunction of the A/C control system
out control of the idle speed control (ISC) servo, and also operates the A/C compressor D Malfunction of the A/C switch
magnetic clutch. D Improper connector contact, open circuit or
short-circuited harness wire
D Malfunction of the engine-A/T-ECU

NG
Check the A/C compressor relay. Replace
(Refer to GROUP 55 ï On-vehicle Service.)
OK
NG
Measure at the engine-A/T-ECU connectors C-122, C-126. Check the A/C system. (Refer to GROUP 55 ï On-vehicle Service.)
D Disconnect the connectors, and measure at the harness side.
D Voltage between 20 and earth, and 83 and earth
(Ignition switch: ON, A/C switch: ON) OK NG
OK: System voltage Check the following Replace
D Short circuit between 20 and earth connectors: C-122,
OK: A/C compressor clutch turns on. C-126
OK

Check the trouble symptom.

NG

Replace the engine-A/T-ECU.

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 13D-64 MPI <4G63> ï Troubleshooting

INSPECTION PROCEDURE 32
Idle speed control (ISC) servo (Stepper motor) system Probable cause
The engine-A/T-ECU controls the intake air volume during idling by opening and closing D Malfunction of the ISC servo
the servo valve located in the bypass air passage. D Improper connector contact, open circuit or
short-circuited harness wire
D Malfunction of the engine-A/T-ECU

NG
Check the ISC servo Replace
(Refer to P.13D-102.)
OK
NG
Measure at the ISC servo connector B-103. Check the harness wire between control relay and ISC servo con-
D Disconnect the connector and measure at the harness side. nector, and repair if necessary.
D Voltage between 2 and earth, and 5 and earth
(Ignition switch: ON)
OK: System voltage
OK

NG NG
Measure at the engine-A/T-ECU connector C-122. Check the following Repair
D Disconnect the connector, measure at the harness side. connector: B-103
D Voltage between each of 14, 15, 28, 29 and earth (Ignition OK
switch: ON)
OK: System voltage Check the trouble symptom.
OK NG
NG
Check the following Repair Check harness wire between engine-A/T-ECU and ISC servo con-
connector: C-122 nector, and repair if necessary.
OK
NG
Check the trouble symptom. Replace the engine-A/T-ECU.

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 MPI <4G63> ï Troubleshooting 13D-65
INSPECTION PROCEDURE 33
Purge control solenoid valve system Probable cause
The purge control solenoid valve controls the purging of air from the canister located D Malfunction of the solenoid valve
inside the intake manifold. D Improper connector contact, open circuit or
short-circuited harness wire.
D Malfunction of the engine-A/T-ECU

NG
Check the purge control solenoid valve. (Refer to GROUP 17 ï Replace
Emission Control System.)
OK
NG
Measure at the purge control solenoid valve connector B-105. Check the harness wire between engine control relay and solenoid
D Disconnect the connector and measure at the harness side. valve connector, and repair if necessary.
D Voltage between 2 and earth (Ignition switch: ON)
OK: System voltage
OK

NG NG
Measure at the engine-A/T-ECU connector C-122. Checkthefollowing connector:B-105 Repair
D Disconnect the connector and measure at the harness side. OK
D Voltage between 34 and earth (Ignition switch: ON)
OK: System voltage Check the trouble symptom.
OK NG
NG
Check the following connector: C-122 Repair Check the harness wire between engine-A/T-ECU and solenoid
OK valve connector, and repair if necessary.
NG
Check the trouble symptom. Replace the engine-A/T-ECU.

INSPECTION PROCEDURE 34
EGR control solenoid valve system Probable cause
The EGR control solenoid valve is controlled by the negative pressure resulting from D Malfunction of the solenoid valve
EGR operation leaking to port “A” of the throttle body. D Improper connector contact, open circuit or
short-circuited harness wire.
D Malfunction of the engine-A/T-ECU

NG
Check the EGR control solenoid valve. (Refer to GROUP 17 ï Replace
Emission Control System.)
OK
NG
Measure at the EGR control solenoid valve connector B-101. Check the harness wire between engine control relay and solenoid
D Disconnect the connector and measure at the harness side. valve connector, and repair if necessary.
D Voltage between 1 and earth (Ignition switch: ON)
OK: System voltage
OK

NG NG
Measure at the engine-A/T-ECU connector C-122. Check the following connector: B-101 Repair
D Disconnect the connector and measure at the harness side.
OK
D Voltage between 6 and earth (Ignition switch: ON)
OK: System voltage Check the trouble symptom.
OK NG
NG
Check the following connector: C-122 Repair Check the harness wire between engine-A/T-ECU and solenoid
OK valve connector, and repair if necessary.

Check the trouble symptom.

NG

Replace the engine-A/T-ECU.

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 13D-66 MPI <4G63> ï Troubleshooting

DATA LIST REFERENCE TABLE

Caution
When shifting the select lever to D range, the brakes should be applied so that the vehicle does
not move forward.
NOTE
*1: In a new vehicle [driven approximately 500 km or less], the air intake plenum pressure is sometimes
10% higher than the standard pressure.
*2. The injector drive time represents the time when the cranking speed is at 250 r/min or below when
the power supply voltage is 11 V.
*3. In a new vehicle [driven approximately 500 km or less], the injector drive time is sometimes 10
longer than the standard time.
*4. In a new vehicle [driven approximately 500 km or less], the step of the stepper motor is sometimes
30 steps greater than the standard value.

Item Inspection Inspection contents Normal condition Inspection Reference

No. item procedure page
No.

11 Oxygen Engine:After having When at 4,000 r/min, 200 mV or less Code No. 13D-13
sensor warmed up engine is suddenly 11
(front) Air/fuel mixture is decelerated
made leaner when de-de
celerating, and is made When engine is 600ï1,000 mV
richer when racing. suddenly raced

Engine:After having Engine is idling 400 mV or less

warmed up (Changes)
The oxygen sensor 600ï1,000 mV
signal is used to check
the air/fuel mixture
ratio, and control 2,500 r/min 400 mV or less
condition is also (Changes)
checked by the en- 600ï1,000 mV
gine-A/T-ECU.

12 Air flow D Engine coolant Engine is idling 18 – 44 Hz ï ï

sensor *1 temperature:
80 ï 95 _C 2 500 r/min
2,500 83 – 123 Hz
D L
Lamps and d allll
accessories: OFF Engine is raced Frequency
D Transmission: increases in
P range response to
racing
13 Intake air Ignition switch: ON or When intake air ï20_C Code No. 13D-16
temperature with engine running temperature is ï20_C 13
sensor
When intake air 0_C
temperature is 0_C

When intake air 20_C

temperature is 20_C

When intake air 40_C

temperature is 40_C

When intake air 80_C

temperature is 80_C

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 MPI <4G63> ï Troubleshooting 13D-67

Item Inspection Inspection contents Normal condition Inspection Reference

No. item procedure page
No.
14 Throttle Ignition switch: ON Set to idle position 535ï735 mV Code No. 13D-18
position 14
sensor Gradually open Increases in
proportion to
throttle opening
angle

Open fully 4,500ï5,000 mV

16 Power Ignition switch: ON System voltage Procedure 13D-59

supply No. 27
voltage
18 Cranking Ignition switch: ON Engine: Stopped OFF Procedure 13D-62
signal No. 29
(ignition Engine: Cranking ON
switch-ST)
21 Engine Ignition switch: ON or When engine ï20_C Code No. 13D-20
coolant with engine running coolant temperature 21
temperature is ï20_C
sensor
When engine 0_C
coolant temperature
is 0_C

When engine 20_C

coolant temperature
is 20_C

When engine 40_C

coolant temperature
is 40_C

When engine 80_C

coolant temperature
is 80_C

22 Crank angle D Engine: Cranking Compare the engine Accord Code No. 13D-22
sensor D Tachometer: speed readings on 22
Connected the tachometer and
the MUT-II/III.
D Engine: Idling When engine 1,103 – 1,303
D Idle position coolant temperature r/min
switch: ON is ï20_C

When engine 1,103 – 1,303

coolant temperature r/min
is 0_C

When engine 1,103 – 1,303

coolant temperature r/min
is 20_C

When engine 924 – 1,124

coolant temperature r/min
is 40_C

When engine 650 – 850 r/min

coolant temperature
is 80_C

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 13D-68 MPI <4G63> ï Troubleshooting

Item Inspection Inspection contents Normal condition Inspection Reference

No. item procedure page
No.
25 Barometric Ignition switch: ON At altitude of 0 m 101 kPa Code No. 13D-58
pressure 25
sensor At altitude of 600 m 95 kPa

At altitude of 1,200 m 88 kPa

At altitude of 1,800 m 81 kPa

27 Power Engine: Idling Steering wheel OFF Procedure 13D-63
steering fluid stationary No. 30
pressure
switch Steering wheel ON
turning

28 A/C switch Engine: Idling A/C switch: OFF OFF Procedure 13D-63
(when A/C switch is No. 31
ON, A/C compressor A/C switch: ON ON
should be operating.)
29 Inhibitor Ignition switch: ON P or N P or N Procedure 13D-62
switch No 29
No.
D, 3, 2, L or R D, 3, 2, L or R
37 Volumetric D Engine coolant Engine is idling 20 ï 30 % ï ï
efficiency temperature:
85ï95_C 2,500 r/min 20 ï 30 %
D p
Lamps, and all
accessories:
i OFF
D Transmission: When engine is Increases
P range suddenly raced

41 Injectors *2 Engine: Cranking When engine 14.7 – 22.1 ms ï ï

coolant temperature
is 0_C (injection is
carried out for all
cylinders
simultaneously)

When engine 26.2 – 39.4 ms

coolant temperature
is 20_C

When engine 6.6 – 9.8 ms

coolant temperature
is 80_C

Injectors*3 D Engine coolant Engine is idling 2.2 – 3.4 ms ï ï

temperature:
85 95_C
85ï95_C
D Lamps, electric 2,500 r/min 2.5 – 3.7 ms
cooling fan and all
accessories: OFF When engine is Increases
D Transmission: suddenly raced
P range

44 Ignition coils D Engine: After Engine is idling 2 – 18_BTDC ï ï

and power having warmed up
transistors D Timing lamp is set.
(The timing lamp is
set in order to 2,500 r/min 20 – 40_BTDC
check actual
ignition timing.)

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 MPI <4G63> ï Troubleshooting 13D-69

Item Inspection Inspection contents Normal condition Inspection Reference

No. item procedure page
No.
45 ISC D Engine coolant A/C switch: OFF 2ï25 STEP ï ï
(stepper) temperature:
motor 85ï95_C
85 95 C
position *4 D Lamps, electric A/C switch: Increases by
cooling fan and all OFF o ON 10ï70 steps
accessories: OFF
D Transmission:
P range
D Engine: Idling D A/C switch: OFF Increases by
D When A/C switch is D Select lever: 5ï50 steps
ON, A/C N range o D
compressor should range
be operating

49 A/C relay Engine: After having A/C switch: OFF OFF (Compressor Procedure 13D-63
warmed up/Engine is clutch is not No. 31
idling operating)

A/C switch: ON ON (Compressor

clutch is
operating)

59 Oxygen Engine: After having Engine is raced 600 ï 1000 mV Code No. 13D-32
sensor warmed up 59
(rear)

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 13D-70 MPI <4G63> ï Troubleshooting

ACTUATOR TEST REFERENCE TABLE

Item Inspection Drive contents Inspection contents Normal Inspection Reference
No. item condition procedure page
No.

01 Injectors Cut fuel to No. 1 Engine: Idling condi- Code No. 13D-29
injector After having warmed up/En- tion becomes 41
gine is idling different (be-
02 Cut fuel to No. 2 (Cut the fuel supply to each comes unsta-
injector injector in turn and check ble).
cylinders which don’t affect
03 Cut fuel to No. 3 idling.)
injector

04 Cut fuel to No. 4

injector

07 Fuel pump Fuel pump D Engine: Pinch the Pulse is felt. Procedure 13D-60
operates and Cranking return hose No. 28
fuel is recircu- D Fuel with fingers
lated. pump: to feel the
Forced pulse of the
driving fuel being
Inspect recirculated.
according
to Listen near Sound of
both the the fuel tank operation is
above for the heard.
condi- sound of fuel
tions. pump
operation.

08 Purge Solenoid valve Ignition switch: ON Sound of op- Procedure 13D-65

control turns from OFF eration can be No. 33
solenoid valve to ON. heard when
solenoid valve
is
driven.

10 EGR Solenoid valve Ignition switch: ON Sound of op- Procedure 13D-65

control turns from OFF eration can be No. 34
solenoid valve to ON. heard when
solenoid valve
is driven.

17 Basic ignition Set the engine- D Engine: Idling 5 _BTDC ï ï

timing A/T-ECU to igni- D Timing light is set
tion timing ad-
justment mode

21 Fan controller Drive the fan D Ignition switch: ON Fan motor Procedure 13D-58
motors D A/C switch: ON runs No. 25

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 MPI <4G63> ï Troubleshooting 13D-71

Needle-nosed wire probe

CHECK AT THE ENGINE-A/T-ECU TERMINALS
TERMINAL VOLTAGE CHECK CHART
1. Connect a needle-nosed wire probe (test harness:
MB991223) to a voltmeter probe.
2. Insert the needle-nosed wire probe into each of the
engine-A/T-ECU connector terminals from the wire side,
and measure the voltage while referring to the check
chart.
NOTE
(1) Make the voltage measurement with the
engine-A/T-ECU connectors connected.
(2) You may find it convenient to pull out the
engine-A/T-ECU to make it easier to reach the
connector terminals.
(3) The checks can be carried out off the order given
in the chart.
Caution
Short-circuiting the positive (+) probe between a
connector terminal and earth could damage the
vehicle wiring, the sensor, engine-A/T-ECU or all of
them. Be careful to prevent this!
3. If voltmeter shows any division from standard value, check
the corresponding sensor, actuator and related electrical
wiring, then repair or replace.
4. After repair or replacement, recheck with the voltmeter
to confirm that the repair has corrected the problem.

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 13D-72 MPI <4G63> ï Troubleshooting

Engine-A/T-ECU Connector Terminal Arrangement

Terminal Check item Check condition (Engine condition) Normal condition

No.

1 No. 1 injector While engine is idling after having warmed From 11 ï 14 V,

up suddenly depress the accelerator pedal.
up, pedal momentarily drops
9 No. 2 injector slightly

24 No. 3 injector

2 No. 4 injector

3 Oxygen sensor Engine: Idling after warming up 1 V or less

(front) heater
Engine r/min: 5,000 r/min System voltage

6 EGR control sole- Ignition switch: “ON” System voltage

noid valve
While engine is idling, suddenly depress the From system voltage,
accelerator pedal momentaly drops

8 Alternator G termi- D Engine: Warm, idle (radiator fan: OFF) Voltage increases by 0.2 ï 3.5 V
nal D Headlamp: OFF o ON
D Stop lamp: OFF o ON
D Rear defogger switch: OFF o ON

11 Ignition coil ï No. 1, Engine r/min: 3,000 r/min 0.3 ï 3.0 V

No. 4

12 Ignition coil ï No. 2,

No. 3

14 Stepper motor coil D Engine: Soon after the warmed up System voltage l 1 V or less
<A> engine is started. (Changes repeatedly)
D A/C switch: OFF o ON (A/C compressor
28 Stepper motor coil is operating)
<B>

15 Stepper motor coil

<C>

29 Stepper motor coil

<D>

18 Fan controller Radiator and condenser fan is not operating 0 ï 0.3 V

Radiator and condenser fan is operating 0.7 V or more

19 Air flow sensor Engine: Idle speed 0ï1V

reset signal
Engine r/min: 3,000 r/min 6ï9V

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 MPI <4G63> ï Troubleshooting 13D-73

Terminal Check item Check condition (Engine condition) Normal condition

No.

20 A/C relay D Engine: Idle speed System voltage or momentarily 6 V

D A/C switch: OFF o ON (A/C compressor or more o 1 V or less
is operating)

21 Fuel pump relay Ignition switch: “ON” System voltage

Engine: Idle speed 1 V or less

22 Engine warning Ignition switch: “LOCK” (OFF) o ”ON” 1 V or less o System voltage (After
lamp several seconds have elapsed)

26 Oxygen sensor Engine: Idling after warming up 1 V or less

(rear) heater
Engine: Racing System voltage

34 Purge control sole- Ignition switch: “ON” System voltage

noid valve
Running at 3,500 r/min while engine is 1 V or less
warming up after having been started

41 Power supply Ignition switch: “ON” System voltage

47

43 Tachometer signal Engine r/min: 3,000 r/min 0.3 ï 3.0 V

44 Engine coolant Ignition switch: “ON” When engine coolant 3.9 ï 4.5 V
temperature sen- temperature is ï20_C
sor
When engine coolant 3.2 ï 3.8 V
temperature is 0_C

When engine coolant 2.3 ï 2.9 V

temperature is 20_C

When engine coolant 1.3 ï 1.9 V

temperature is 40_C

When engine coolant 0.7 ï 1.3 V

temperature is 60_C

When engine coolant 0.3 ï 0.9 V

temperature is 80_C

45 Crank angle sen- Engine: Cranking 0.4 ï 4.0 V

sor
Engine: Idle speed 1.5 ï 2.5 V

46 Sensor impressed Ignition switch: “ON” 4.9 ï 5.1 V

voltage

49 Engine control Ignition switch: “LOCK” (OFF) System voltage

relay
(power supply) Ignition switch: “ON” 1 V or less

52 Power steering Engine: Idling after When steering wheel System voltage
fluid pressure warmed up is stationary
switch
When steering wheel 1 V or less
is turned

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 13D-74 MPI <4G63> ï Troubleshooting

Terminal Check item Check condition (Engine condition) Normal condition

No.

54 Alternator FR D Engine: Warm, idle (radiator fan: OFF) Voltage decreases

terminal D Headlamp: OFF o ON
D Stop lamp: OFF o ON
D Rear defogger switch: OFF o ON

55 Barometric pres- Ignition switch: When altitude is 0 m 3.8 ï 4.2 V

sure sensor “ON”
When altitude is 3.5 ï 3.9 V
600 m

When altitude is 3.3 ï 3.7 V

1,200 m

When altitude is 3.0 ï 3.4 V

1,800 m

56 Camshaft position Engine: Cranking 0.4 ï 3.0 V

sensor
Engine: Idling 1.5 ï 3.0 V

58 Ignition switch ï ST Engine: Cranking 8 V or more

61 A/C load signal Refer to GROUP 55 ï Troubleshooting

(Inspection at Automatic compressor ï ECU terminal)

64 Intake air Ignition switch: When intake air tem- 3.8 ï 4.4 V
temperature “ON” perature is ï20_C
sensor
When intake air 3.2 ï 3.8 V
temperature is 0_C

When intake air 2.3 ï 2.9 V

temperature is 20_C

When intake air 1.5 ï 2.1 V

temperature is 40_C

When intake air 0.8 ï 1.4 V

temperature is 60_C

When intake air 0.4 ï 1.0 V

temperature is 80_C

65 Air flow sensor Engine: Idle speed 2.2 ï 3.2 V

Engine r/min: 2,500 r/min

66 Backup power Ignition switch: “LOCK” (OFF) System voltage

supply

71 Oxygen sensor Engine: Running at 2,500 r/min after warmed 0 l 0.8 V (Changes repeatedly)
(front) up (Check using a digital type voltmeter)

73 Oxygen sensor Engine: Idling after warmed up (Check using 0 l 0.6 V (Changes repeatedly)
(rear) a digital type voltmeter)

78 Throttle position Ignition switch: Set throttle valve to 0.535 ï 0.735 V

sensor “ON” idle position

Fully open throttle 4.4 ï 5.3 V

valve

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 MPI <4G63> ï Troubleshooting 13D-75

Terminal Check item Check condition (Engine condition) Normal condition

No.

83 A/C switch Engine: Idle speed Turn the A/C switch 0.5 V or less
OFF

Turn the A/C switch System voltage

ON (A/C compressor
is operating)

98 Ignition switch ï IG Ignition switch: “ON” System voltage

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 13D-76 MPI <4G63> ï Troubleshooting

CHECK CHART FOR RESISTANCE AND CONTINUITY

BETWEEN TERMINALS
1. Turn the ignition switch to “LOCK” (OFF) position.
2. Disconnect the engine-A/T-ECU connector.
3. Measure the resistance and check for continuity between
the terminals of the engine-A/T-ECU harness-side
connector while referring to the check chart.
NOTE
(1) When measuring resistance and checking continuity,
a harness for checking contact pin pressure should
be used instead of inserting a test probe.
(2) Checking need not be carried out in the order given
in the chart.
Caution
If the terminals that should be checked are mistaken,
or if connector terminals are not correctly shorted
to earth, damage may be caused to the vehicle wiring,
sensors, engine-A/T-ECU and/or ohmmeter.
Be careful to prevent this!
4. If the ohmmeter shows any deviation from the standard
value, check the corresponding sensor, actuator and
related electrical wiring, and then repair or replace.
5. After repair or replacement, recheck with the ohmmeter
to confirm that the repair or replacement has corrected
the problem.

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 MPI <4G63> ï Troubleshooting 13D-77
Engine-A/T-ECU Harness Side Connector Terminal Arrangement

Terminal Inspection item Normal condition (Check condition)

No.

1 ï 41 No. 1 injector 10.5 ï 13.5 : (At 20_C)

9 ï 41 No. 2 injector

24 ï 41 No. 3 injector

2 ï 41 No. 4 injector

3 ï 41 Oxygen sensor (front) heater 4.5 ï 8.0 : (At 20_C)

6 ï 41 EGR control solenoid valve 30 ï 34 : (At 20_C)

14 ï 41 Stepper motor coil (A) 28 ï 33 : (At 20_C)

28 ï 41 Stepper motor coil (B)

15 ï 41 Stepper motor coil (C)

29 ï 41 Stepper motor coil (D)

26 ï 41 Oxygen sensor (rear) heater 11 ï 18 : (At 20_C)

34 ï 41 Purge control solenoid valve 29 ï 35 : (At 20_C)

42 ï Body Engine-A/T-ECU earth Continuity (0 :)

earth

48 ï Body
earth

44 ï 57 Engine coolant temperature sensor 14 ï 17 k:

(When coolant temperature is ï20_C)

5.1 ï 6.5 k:
(When coolant temperature is 0_C)

2.1 ï 2.7 k:
(When coolant temperature is 20_C)

0.9 ï 1.3 k:
(When coolant temperature is 40_C)

0.48 ï 0.68 k:
(When coolant temperature is 60_C)

0.26 ï 0.36 k:
(When coolant temperature is 80_C)

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 13D-78 MPI <4G63> ï Troubleshooting

Terminal Inspection item Normal condition (Check condition)

No.

64 ï 16 Intake air temperature sensor 13 ï 17 k:

(When intake air temperature is ï20_C)

5.3 ï 6.7 k:
(When intake air temperature is 0_C)

2.3 ï 3.0 k:
(When intake air temperature is 20_C)

1.0 ï 1.5 k:
(When intake air temperature is 40_C)

0.56 ï 0.76 k:
(When intake air temperature is 60_C)

0.30 ï 0.42 k:
(When intake air temperature is 80_C)

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 MPI <4G63> ï Troubleshooting 13D-79
INSPECTION PROCEDURE USING AN
Oscilloscope OSCILLOSCOPE
The output signals of the sensors and the conditions of the
Special
actuation signals of the actuators can be inspected visually
patterns by observing the waveforms on the oscilloscope.
pickup
AIR FLOW SENSOR
Measurement Method
1. Disconnect the air flow sensor connector, and connect
the special tool test harness (MB991709) in between (All
terminals should be connected).
2. Connect the oscilloscope special patterns pickup to air
flow sensor connector terminal No. 3.
Alternate Method (Test harness not available)
1. Connect the oscilloscope special patterns pickup to
engine-A/T-ECU terminal No. 65.
Standard Wave Pattern
Observation conditions

Function Special patterns

Pattern height Low
Pattern selector Display
Engine r/min Idle

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 13D-80 MPI <4G63> ï Troubleshooting

Standard wave pattern

(V)
10 T The time (cycle time) T is reduced when
the amount of intake air increases.
T1 T2 Times T1 and T2 are equal.

Time
0

Observation conditions (from conditions above engine speed is increased by racing.)

(V)

10 T

Time
0

Wave Pattern Observation Points

Check that cycle time T becomes shorter and the frequency increases when the engine speed is increased.

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 MPI <4G63> ï Troubleshooting 13D-81
Examples of Abnormal Wave Patterns
D Example 1
Cause of problem
Sensor interface malfunction
Wave pattern characteristics
Rectangular wave pattern is output even when the engine
is not started.
D Example 2
Cause of problem
Damaged rectifier or vortex generation column
Wave pattern characteristics
Unstable wave pattern with nonïuniform frequency.
However, when an ignition leak occurs during acceleration,
the wave pattern will be distorted temporarily, even if
the air flow sensor is normal.

Camshaftposition CAMSHAFT POSITION SENSOR AND CRANK ANGLE

sensor connector Oscilloscope
SENSOR
Special patterns Measurement Method
pick-up
1. Disconnect the camshaft position sensor connector and
connect the special tool test harness (MB991709) in
between (All terminals should be connected).
2. Connect the oscilloscope special pattern pickup to
camshaft position sensor terminal No. 2.
Crank angle 3. Disconnect the crank angle sensor connector and connect
sensor connector the special tool test harness (MD998478) in between.
4. Connect the oscilloscope special patterns pickup to crank
angle sensor terminal No. 2.
Alternate Method (Test harness not available)
1. Connect the oscilloscope special patterns pickup to
engine-A/T-ECU terminal No. 56 (When checking the
camshaft position sensor signal wave pattern).
2. Connect the oscilloscope special patterns pickup to
engine-A/T-ECU terminal No. 45 (When checking the
crank angle sensor signal wave pattern).

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 13D-82 MPI <4G63> ï Troubleshooting

Standard Wave Pattern

Observation condition
Function Special patterns

Pattern height Low

Pattern selector Display

Engine r/min Idle

Standard wave pattern

(V) 2 engine revolutions

(1 camshaft revolution) The time (cycle time) T is
75_BTDC reduced when the engine
5_BTDC T speed increases

Crank angle
sensor output
wave pattern

Camshaft position
sensor output
wave pattern

Time
0
TDC: Top dead centre No. 1 TDC No. 3 TDC No. 4 TDC No. 2 TDC

Wave Pattern Observation Points

Check that cycle time T becomes shorter when the engine speed increases.

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 MPI <4G63> ï Troubleshooting 13D-83
Examples of Abnormal Wave Patterns
D Example 1
Cause of problem
Sensor interface malfunction
Wave pattern characteristics
Rectangular wave pattern is output even when the engine
is not started.

D Example 2
Cause of problem
Loose timing belt
Abnormality in sensor disk
Wave pattern characteristics
Wave pattern is displaced to the left or right.

INJECTOR
Oscilloscope
Measurement Method
1. Disconnect the injector connector, and then connect the
special tool test harness set (MB991348) in between (All
terminals should be connected).
Special 2. Connect the oscilloscope special patterns pickup to
patterns
pickup terminal No. 2 of the injector connector.

Alternate Method (Test harness not available)

1. Connect the oscilloscope special patterns pickup to
engine-A/T-ECU terminal No. 1 (When checking the No.
1 cylinder).
2. Connect the oscilloscope special patterns pickup to
engine-A/T-ECU terminal No. 9 (When checking the No.
2 cylinder).
3. Connect the oscilloscope special patterns pickup to
engine-A/T-ECU terminal No. 24 (When checking the No.
3 cylinder).
4. Connect the oscilloscope special patterns pickup to
engine-A/T-ECU terminal No. 2 (When checking the No.
4 cylinder).

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 13D-84 MPI <4G63> ï Troubleshooting

Standard Wave Pattern

Observation conditions
Function Special patterns

Pattern height Variable

Variable knob Adjust while viewing the wave pattern

Pattern selector Display

Engine speed Idle

Standard wave pattern

(V) Point A

Solenoid back
50 electromotive
force
(Approx. 7u10 V)

Point B
Injector drive time
Time
Power
voltage

0 Drive signal: ON Drive signal: OFF

Wave Pattern Observation Points

Point A: Height of solenoid back electromotive force
Contrast with standard wave pattern Probable cause

Solenoid coil back electromotive force is low or doesn’t Short in the injector solenoid
appear at all.

Point B: Injector drive time

D The injector drive time will be synchronized with the

M.U.T.-II/III tester display.
D When the engine is suddenly raced, the drive time will
be greatly extended at first, but the drive time will soon
match the engine speed.

When idling
When racing

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 MPI <4G63> ï Troubleshooting 13D-85
IDLE SPEED CONTROL (ISC) SERVO (STEPPER
Oscilloscope MOTOR)
Measurement Method
1. Disconnect the ISC servo connector, and connect the
Special special tool test harness (MB991709) in between.
patterns
pickup 2. Connect the oscilloscope special patterns pickup to the
ISC servo side connector terminal No. 1, No. 3, No. 4
and No. 6 respectively.

Alternate Method (Test harness not available)

1. Connect the oscilloscope special patterns pickup to
engine-A/T-ECU terminal No. 14, connection terminal No.
15, connection terminal No. 28, and connection terminal
No. 29 respectively.
Standard wave pattern
Observation conditions
Function Special patterns

Pattern height High

Pattern selector Display

Engine condition When the engine coolant temperature is 20˚C or below, turn the ignition switch from ”LOCK”
(OFF) position to ”ON” (without starting the engine).

While the engine is idling, turn the A/C switch to ON.

Immediately after starting the warm engine.

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 13D-86 MPI <4G63> ï Troubleshooting

Standard wave pattern

(V) The wave pattern

appears for an Point B Point A
instant, but soon Coilreverse electromotive Induced electromotive force
disappears. force (Approx. 3 u 10 V) from the motor turning
30
Stepper
motor
control 20
signal
wave
pattern
10

Time

Wave pattern Observation Points

Check that the standard wave pattern appears when the stepper motor is operating.
Point A: Presence or absence of induced electromotive force from the motor turning (Refer to the abnormal
wave pattern).
Contrast with standard wave pattern Probable cause

Induced electromotive force does not appear or is extremely small. Motor is malfunctioning

Point B: Height of coil reverse electromotive force

Contrast with standard wave pattern Probable cause

Coil reverse electromotive force does not appear or is extremely small. Short in the coil

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 MPI <4G63> ï Troubleshooting 13D-87
Examples of Abnormal Wave Pattern
D Example 1
Cause of problem
Motor is malfunctioning. (Motor is not operating.)
Wave pattern characteristics
Induced electromotive force from the motor turning does
not appear.

D Example 2
Open Cause of problem
circuit
side Open circuit in the line between the stepper motor and
the engine-A/T-ECU.
Wave pattern characteristics
Current is not supplied to the motor coil on the open
circuit side (Voltage does not drop to 0 V).
Normal Furthermore, the induced electromotive force waveform
side at the normal side is slightly different from the normal
waveform.

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 13D-88 MPI <4G63> ï Troubleshooting

IGNITION COIL AND POWER TRANSISTOR

Oscilliscope
Measurement Method
1. Disconnect the ignition coil connector, and connect the
Special special tool test harness set (MB991348) in between (All
patterns terminals should be connected).
pickup 2. Connect the oscilloscope special patterns pickup to
terminal No. 3 of each ignition coil connector in turn.
Alternate Method (Test harness not available)
1. Connect the oscilloscope special patterns pickup to
engine-A/T-ECU terminal No. 11 (No. 1 ï No. 4),
connection terminal No. 12 (No. 2 ï No.3) respectively.
Standard Wave Pattern
Observation condition
Function Special patterns
Pattern height Low
Pattern selector Display
Engine r/min Approximately 1,200 r/min

Standard wave pattern

(V)
T
6
5_BTDC
4 75_BTDC
Compression top dead center
Crank angle
sensor output 2
wave pattern
0

4
T1 T
Ignition period
Power transistor 2
control signal
wave pattern
0

OFF ON
Dwell section
T: Revolution time corresponding to a crank angle of 180_
T1: Time computed by the engine-A/T-ECU
T: Spark advance angle

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 MPI <4G63> ï Troubleshooting 13D-89
Wave Pattern Observation Points
Point: Condition of wave pattern build-up section and maximum voltage (Refer to abnormal wave pattern
examples 1 and 2).

Condition of wave pattern build-up section and maximum voltage Probable cause

Rises from approximately 2 V to approximately 4.5 V at the Normal

top-right

2 V rectangular wave Open-circuit in ignition primary circuit

Rectangular wave at power voltage Power transistor malfunction

Examples of Abnormal Wave Patterns

D Example 1
Normal wave pattern
Wave pattern during engine cranking
Cause of problem
Open-circuit in ignition primary circuit
2V Wave pattern characteristics
Topïright part of the buildïup section cannot be seen,
and voltage value is approximately 2 V too low.

D Example 2
Normal wave pattern Wave pattern during engine cranking
VB
Cause of problem
Malfunction in power transistor
Wave pattern characteristics
Power voltage results when the power transistor is ON.

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 13D-90 MPI <4G63> ï On-vehicle Service

ON-VEHICLE SERVICE
THROTTLE BODY (THROTTLE VALVE AREA)
CLEANING
1. Remove the air intake hose from the throttle body.
2. Spray cleaning fluid on a clean cloth.
Caution
D Do not spray the cleaning fluid directly to the
15 mm throttle valve.
D Make sure the cleaning fluid does not enter the
15 mm motor from the bypass line. Also make sure it
does not enter the sensor through the shaft.
D Be careful not to rub off the molybden applied
around the throttle valve shaft.
Areas on throttle valve to
apply molybdenum disulfide 3. Wipe off the dirt around the throttle valve with the cloth
sprayed with cleaning fluid.
4. Attach the air intake hose.
5. Adjust the basic idle speed (Refer to P.13D-91.)

THROTTLE POSITION SENSOR ADJUSTMENT

Throttle position
sensor 1. Connect the M.U.T.-II/III to the diagnosis connector.
When not using the M.U.T.-II/III, proceed as follows.

Equipment side connector

(1) Disconnect the throttle position sensor connector and

connect the special tool test harness (MB991536)
between the disconnected connector taking care not
Throttle position to confuse the terminal to be connected.
sensor
(2) Connect digital voltmeter between the terminal No.
2 (special tool’s yellow clip on the sensor output)
and the terminal No. 4 (special tool’s red clip on the
MB991536 sensor earth) of the throttle position sensor connector.
2. Turn the ignition switch to ”ON” position (but do not start
the engine).
3. Check the output voltage of the throttle position sensor.
Standard value: 535 ï 735 mV

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 MPI <4G63> ï On-vehicle Service 13D-91
4. If not within the standard value, loosen the throttle position
sensor mounting bolts. Then rotate the sensor body to
adjust.
5. Turn the ignition switch to ”LOCK” (OFF) position.
6. Remove the M.U.T.-II/III. If the M.U.T.-II/III is not used,
remove the special tool, and then connect the throttle
position sensor connector.
7. If a diagnosis code is displayed, erase the diagnosis code
by using the M.U.T.-II/III or disconnect the negative battery
cable from the battery terminal and then leave it for at
least 10 seconds. After that, reconnect the battery cable,
and then let the engine run at idle for approximately 10
minutes.

BASIC IDLE SPEED ADJUSTMENT

Caution
D The standard idling speed has been adjusted by the
speed adjusting screw (SAS) by the manufacturer,
and there should usually be no need for readjustment.
D If the adjustment has been changed by mistake, the
idle speed may become too high or the idle speed
may drop too low when loads from components such
as the A/C are placed on the engine. If this occurs,
adjust by the following procedure.
D The adjustment, if made, should be made after first
confirming that the spark plugs, the injectors, the
idle speed control servo, the compression pressure,
etc., are all normal.
1. Before inspection and adjustment, set the vehicle to the
pre-inspection condition.
2. Connect the M.U.T.-II/III to the diagnosis connector
(16-pin).
NOTE
When the M.U.T.-II/III is connected, the diagnosis control
terminal should be earthed.
3. Start the engine and run at idle.
4. Select the item No. 30 of the M.U.T.-II/III actuator test.
NOTE
This holds the ISC servo at the basic step to adjust the
basic idle speed.
5. Check the idle speed.
Standard value: 750 r 50 r/min

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 13D-92 MPI <4G63> ï On-vehicle Service

NOTE
(1) The engine speed may be 20 to 100 r/min lower
than indicated above for a new vehicle [driven
approximately 500 km or less], but no adjustment
is necessary.
(2) If the engine stalls or the engine speed is low even
though the vehicle has been driven approximately
500 km or more, it is probable that deposits are
adhered to the throttle valve, so clean it (Refer to
P.13D-90.)

6. If not within the standard value range, turn the speed

adjusting screw (SAS) to make the necessary adjustment.
NOTE
If the idling speed is higher than the standard value range
even when the SAS is fully closed, check whether or
not there is any indication that the fixed SAS has been
moved. If there is an indication that it has been moved,
adjust the fixed SAS.
7. Press the M.U.T.-II/III clear key, and release the ISC
servo from the actuator test mode.
NOTE
Unless the ISC servo is released, the actuator test mode
will continue 27 minutes.
8. Turn the ignition switch to ”LOCK” (OFF) position.
9. Disconnect the M.U.T.-II/III.
10. Start the engine again and let it run at idle speed for
about 10 minutes; check that the idling condition is normal.

FUEL PRESSURE TEST

1. Release residual pressure from the fuel pipe line to prevent
fuel gush out.
Caution
Cover the hose connection with rags to prevent splash
of fuel that could be caused by some residual pressure
in the fuel pipe line.
2. Disconnect the high-pressure fuel hose at the delivery
pipe side.

3. Assemble the fuel pressure measurement tools as follows.

MB991637
<When using the fuel pressure gauge set (special tool)>
Gasket
(1) Remove the union joint and bolt from the special
MD998709 tool adaptor hose (MD998709) and attach the special
tool hose adaptor (MD998742) to the adaptor hose.
Delivery (2) Via a gasket, install the special tool fuel pressure
pipe MD998742
gauge set (MB991637 or MB991981) into the special
High-pressure tool that has already assembled as described in (a)
fuel hose
above.

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 MPI <4G63> ï On-vehicle Service 13D-93
<When using the fuel pressure gauge>
(1) Remove the union joint and bolt from special tool
adaptor hose (MD998709) and attach the special tool
hose adaptor (MD998742) to the adaptor hose.
(2) Via a suitable O-ring or gasket, install the fuel pressure
gauge to the special tool that has already assembled
MB991981 as described in (a) above.

Gasket

MD998709
Delivery
pipe
MD998742
High-pressure
fuel hose

Fuel pressure 4. Install the assembled fuel pressure measurement tools

gauge set between the fuel rail and high-pressure fuel hose.
O-ring or gasket Caution
To prevent damage to the M.U.T.-II/III, always turn
MD998709
Delivery the ignition switch to the ”LOCK” (OFF) position before
pipe connecting or disconnecting the M.U.T.-II/III
MD998742
5. Connect the M.U.T.-II/III to the diagnosis connector.
High-pressure 6. Turn the ignition switch to ”ON” position (But do not start
fuel hose
the engine)
7. Select ”Item No. 07” from the M.U.T.-II/III actuator test
to drive the fuel pump. Check that there are no fuel leaks
from any parts.
8. Finish the actuator test or turn the ignition switch to ”LOCK”
(OFF) position.
9. Start the engine and run at idle.
10. Fuel pressure measurement while the engine is running
at idle.
Standard value: Approximately 265 kPa at kerb idle

11. Disconnect the vacuum hose from the fuel pressure

regulator and measure fuel pressure with the hose end
Vacuum hose
closed by a finger.
Standard value: 324 ï 343 kPa at kerb idle
12. Check to see that fuel pressure at idle does not drop
even after the engine has been raced several times.
13. Racing the engine repeatedly, hold the fuel return hose
lightly with fingers to feel that fuel pressure is present
in the return hose.

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 13D-94 MPI <4G63> ï On-vehicle Service

NOTE
If the fuel flow rate is low, there will be no fuel pressure
in the return hose.
14. If any of fuel pressure measured in steps 10 to 13 is out of
specification, troubleshoot and repair according to the
table below.

Symptom Probable cause Remedy

D Fuel pressure too low Clogged fuel filter Replace fuel filter
D Fuel pressure drops after racing
D No fuel pressure in fuel return Fuel leaking to return side due to poor Replace fuel pressure regulator
hose fuel regulator valve seating or settled
spring

Low fuel pump delivery pressure Replace fuel pump

Fuel pressure too high Binding valve in fuel pressure Replace fuel pressure regulator
regulator

Clogged fuel return hose or pipe Clean or replace hose or pipe

Same fuel pressure when vacuum Damaged vacuum hose or Clogged Replace vacuum hose or clean nipple
hose is connected and when discon- nipple
nected

15. Stop the engine and check change of fuel pressure gauge
reading. Normal if the reading does not drop within 2
minutes. If it does, observe the rate of drop and
troubleshoot and repair according to the table below.

Symptom Probable cause Remedy

Fuel pressure drops gradually after Leaky injector Replace injector

engine is stopped
Leaky fuel regulator valve seat Replace fuel pressure regulator

Fuel pressure drops sharply Check valve in fuel pump is held open Replace fuel pump
immediately after engine is stopped

16. Release residual pressure from the fuel pipe line.

Caution
Cover the hose connection with rags to prevent splash
of fuel that could be caused by some residual pressure
in the fuel pipe line.
17. Remove the fuel pressure gauge and special tool from
the delivery pipe.
18. Replace the O-ring at the end of the fuel high pressure
hose with a new one. Furthermore, apply engine oil to
the new O-ring before replacement.
19. Fit the fuel high pressure hose over the delivery pipe
and tighten the bolt to specified toque.
Tightening torque: 5.0 r 1.0 N·m
20. Check for any fuel leaks by following the procedure in
step 7.
21. Disconnect the M.U.T.-II/III.

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 MPI <4G63> ï On-vehicle Service 13D-95
COMPONENT LOCATION
Name Symbol Name Symbol

Air flow sensor G Engine warming lamp S

(with intake air temperature sensor and (check engine lamp)
barometric pressure sensor)
Fan controller M

A/C compressor relay H Fuel pump relay (1) and (2) R

A/C switch U Idle speed control servo E
Camshaft position sensor O Ignition coil L

Crank angle sensor B Injector C

Detonation sensor J Oxygen sensor (front) K
Diagnosis connector T Oxygen sensor (rear) Q
EGR control solenoid valve I Power steering fluid pressure switch A

Engine control relay H Purge control solenoid valve I

Engine coolant temperature sensor N Throttle position sensor D
Engine-A/T-ECU V Vehicle speed sensor F

A B C D E F G H

R S T U V
I J K L M N O P

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 13D-96 MPI <4G63> ï On-vehicle Service

ENGINE CONTROL RELAY CONTINUITY CHECK

Engine control
relay
Relay box’s Tester Connection Battery Voltage Normal State
triangle marks Terminal
2ï3 No Voltage Continuity
1ï4 No Voltage No continuity
Voltage (Connect Continuity
positive (+) terminal
of battery to termi-
Equipment nal No. 2 and nega-
side connector
tive (ï) terminal of
battery to terminal
No. 3.)

Junction block’s
FUEL PUMP RELAY CONTINUITY CHECK
triangle marks
Fuel pump Tester Connection Battery Voltage Normal State
relay (1)
Terminal
1ï4 No Voltage Continuity
Fuel pump
relay (2) 2ï3 No Voltage No continuity
Voltage (Connect Continuity
Equipment positive (+) terminal
side connector of battery to termi-
nal No. 1 and nega-
tive (ï) terminal of
battery to terminal
No. 4.)

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 MPI <4G63> ï On-vehicle Service 13D-97
INTAKE AIR TEMPERATURE SENSOR CHECK
Air flow sensor 1. Disconnect the air flow sensor connector.
2. Measure resistance between terminals No. 5 and No.
6.
Standard value:
13 ï 17 k: (at ï20_C)
5.3 ï 6.7 k: (at 0_C)
2.3 ï 3.0 k: (at 20_C)
1.0 ï 1.5 k: (at 40_C)
Equipment side connector 0.56 ï 0.76 k: (at 60_C)
0.30 ï 0.42 k: (at 80_C)
3. Remove the air flow sensor
Intake air temperature 4. Measure resistance while heating the sensor using a hair
sensor drier.
Normal condition:
Temperature (_C) Resistance (k:)
Higher Smaller
5. If the value deviates from the standard value or the
resistance remains unchanged, replace the air flow sensor
assembly.
6. Install the air flow sensor and tighten it to the specified
torque.
Tightening torque: 8.8 r 1 N·m

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 13D-98 MPI <4G63> ï On-vehicle Service

ENGINE COOLANT TEMPERATURE SENSOR

CHECK
Engine coolant
temperature sensor Caution
Be careful not to touch the connector (resin section) with
the tool when removing and installing.
1. Remove the engine coolant temperature sensor.

Equipment side connector

2. With temperature sensing portion of engine coolant

temperature sensor immersed in hot water, check
resistance.
Standard value:
14 ï 17 k: (at ï20_C)
5.1 ï 6.5 k: (at 0_C)
2.1 ï 2.7 k: (at 20_C)
0.9 ï 1.3 k: (at 40_C)
0.48 ï 0.68 k: (at 60_C)
0.26 ï 0.36 k: (at 80_C)

3. If the resistance deviates from the standard value greatly,

replace the sensor.
4. Apply sealant to threaded portion.
Specified sealant:
3M NUT Locking Part No. 4171 or equivalent
5. Install the engine coolant temperature sensor and tighten
it to the specified torque.
Tightening torque: 29 r 10 N·m

THROTTLE POSITION SENSOR CHECK

Throttle position sensor 1. Disconnect the throttle position sensor connector.
2. Measure the resistance between the throttle position
sensor side connector terminal No. 1 and terminal No.
4.
Standard value: 3.5 ï 6.5 k:
Equipment side connector
3. Measure the resistance between the throttle position
sensor side connector terminal No. 2 and terminal No.
4.
Normal condition:
Throttle valve slowly open Changes smoothly in
until fully open from the idle proportion to the opening
position angle of the throttle valve
4. If the resistance is outside the standard value, or if it
doesn’t change smoothly, replace the throttle position
sensor.
NOTE
For the throttle position sensor adjustment procedure,
refer to P.13D-90.

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 MPI <4G63> ï On-vehicle Service 13D-99
Oxygen sensor OXYGEN SENSOR CHECK
(front)
connector Oxygen sensor (front)
1. Disconnect the oxygen sensor connector and connect
the special tool test harness (MD998464) to the connector
on the oxygen sensor side.
2. Make sure that there is continuity (4.5 ï 8.0 : at 20˚C)
Oxygen sensor between terminal No. 1 (red clip of special tool) and No.
(front) 3 (blue clip of special tool) on the oxygen sensor connector.
3. If there is no continuity, replace the oxygen sensor.
Equipment side connector 4. Warm up the engine until engine coolant is 80˚C or higher.

5. Perform a tracing for 5 minutes or more with the engine

speed of 4,500 r/min.
6. Connect a digital voltage meter between terminal No.
Oxygen
Black sensor 2 (black clip of special tool) and No. 4 (white clip of special
equipment tool).
side connector 7. While repeatedly racing the engine, measure the oxygen
White sensor output voltage.
Standard value:
Engine Oxygen sensor Remarks
MD998464 output voltage
When 0.6 ï 1.0 V If you make the air-fuel ratio
racing the rich by racing the engine
engine repeatedly, a normal oxy-
gen sensor will output a
voltage of 0.6 ï 1.0 V.

Caution
D Be very careful when connecting the jumper wire;
incorrect connection can damage the oxygen
sensor.
D Be careful the heater is broken when voltage of
beyond 8V is applied to the oxygen sensor heater.
NOTE
If the sufficiently high temperature (of approximate 400˚C
or more) is not reached although the oxygen sensor is
normal, the output voltage would be possibly low although
the rich air-fuel ratio. Therefore, if the output voltage is
low, use a jumper wire to connect the terminal No.1 (red
clip of special tool) and the terminal No. 3 (blue clip of
special tool) of the oxygen sensor with a (+) terminal
and (ï) terminal of 8 V power supply respectively, then
check again.
8. If the sensor is defective, replace the oxygen sensor.
NOTE
For removal and installation of the oxygen sensor, refer
to GROUP 15 ï Exhaust Manifold.

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 13D-100 MPI <4G63> ï On-vehicle Service

Oxygen sensor (rear)

Oxygen sensor
1. Disconnect the oxygen sensor connector and connect
(rear) the special tool test harness (MB991658) to the connector
on the oxygen sensor side.
2. Make sure that there is continuity (11 ï 18 : at 20˚C)
between terminal No. 3 and No. 4 on the oxygen sensor
connector.
3. If there is no continuity, replace the oxygen sensor.
4. Warm up the engine until engine coolant is 80˚C or higher.
5. Perform a tracing for 5 minutes or more with the engine
speed of 4,500 r/min.
6. Connect a digital voltage meter between terminal No.
1 and No. 2.
Oxygen sensor
(rear) connector

Equipment side connector

7. While repeatedly racing the engine, measure the oxygen

sensor output voltage.
Standard value:

Oxygen Engine Oxygen sensor Remarks

sensor output voltage
When 0.6 ï 1.0 V If you make the air-fuel ratio
racing the rich by racing the engine
engine repeatedly, a normal oxy-
gen sensor will output a
MB991658 voltage of 0.6 ï 1.0 V.

Caution
D Be very careful when connecting the jumper wire;
incorrect connection can damage the oxygen
sensor.
D Be careful the heater is broken when voltage of
beyond 12 V is applied to the oxygen sensor
heater.
NOTE
If the sufficiently high temperature (of approximately
400˚C or more) is not reached although the oxygen sensor
is normal, the output voltage would be possibly low
although the rich air-fuel ratio. Therefore, if the output
voltage is low, use a jumper wire to connect the terminal
No.3 and the terminal No. 4 of the oxygen sensor with
a (+) terminal and (ï) terminal of 12 V power supply
respectively, then check again.
8. If the sensor is defective, replace the oxygen sensor.
NOTE
For removal and installation of the oxygen sensor, refer
to GROUP 15 ï Exhaust Pipe and Main Muffler .

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 MPI <4G63> ï On-vehicle Service 13D-101
INJECTOR CHECK
Injector Check the Operation Sound
1. Use a stethoscope to listen to the operation sound
Equipment (clicking) of the injectors while the engine is idling or
side connector
cranking.
Caution
Beware that the operation sounds of other injectors
can be heard even if the injector that is being inspected
might not be operating.
2. Verify that the operation sound increases with the engine
speed.
NOTE
If the operating sound cannot be heard, inspect the injector
actuation circuit.
Measurement of Resistance between Terminals
1. Disconnect the injector connector.
2. Measure the resistance between terminals.
Standard value: 10.5 ï 13.5 : (at 20_C)
3. Connect the injector connector.

Check the Injection Condition

1. Following the steps below, bleed out the residual pressure
within the fuel pipe line to prevent flow of the fuel.
2. Remove the injector.
3. Assemble the following special tools as shown in Fig.
Fuel pressure D Injector test set (MB992076)
regulator D Injector test harness (MB991607)
D Injector test adaptor (MD998741)
MD998741
D Injector test holder assembly (MB991976)
High-pressure 4. Connect the M.U.T.-II/III to the diagnosis connector.
fuel hose
MB992076
5. Turn the ignition switch to ”ON” position (But do not start
MB991607 the engine).
Return hose 6. Select ”Item No. 07” from the M.U.T.-II/III actuator test
MB991976 to drive the fuel pump.

Battery
Injector

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 13D-102 MPI <4G63> ï On-vehicle Service

7. Activate the injector and check the atomized spray

condition of the fuel.
The condition can be considered satisfactory unless it
is extremely poor.
8. Stop the actuation of the injector, and check for leakage
from the injector’s nozzle.
Fuel pressure
regulator Standard value: 1 drop or less per minute
9. Without the fuel pump operation, operate the injector
to draw the fuel out.
High-pressure 10. If the spraying is extremely poor or the fuel leakage from
fuel hose the injector nozzle deviates from the standard value,
replace the injector.
Return hose 11. Disconnect the M.U.T.-II/III.

Injector
Battery

IDLE SPEED CONTROL (ISC) SERVO

(STEPPER MOTOR) CHECK
Check the Operation Sound
Equipment side 1. Check that the engine coolant temperature is 20˚C or
connector below.
NOTE
Disconnecting the engine coolant temperature sensor
Idle speed connector and connecting the harness-side of the
control servo connector to another engine coolant temperature sensor
that is at 20˚C or below is also okay.
2. Check that the operation sound of the stepper motor
can be heard after the ignition is turned to the “ON” position
(but without starting the engine).
3. If the operation sound cannot be heard, check the stepper
motor’s activation circuit.
If the circuit is normal, it is probable that there is a
malfunction of the stepper motor or of the engine-A/T-ECU.

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 MPI <4G63> ï On-vehicle Service 13D-103
Check the Coil Resistance
1. Disconnect the idle speed control servo connector.
2. Measure the resistance between terminal No. 2 and either
terminal No. 1 or terminal No. 3 of the connector at the
idle speed control servo side.
Standard value: 28 ï 33 : (at 20_C)
3. Measure the resistance between terminal No. 5 and either
terminal No. 6 or terminal No. 4 of the connector at the
idle speed control servo side.
Standard value: 28 ï 33 : (at 20_C)
4. If the resistance deviates from the standard value greatly,
replace the idle speed control servo.

Operation Check
1. Remove the throttle body.
2. Remove the stepper motor.
3. Connect the special tool Test harness (MB991709) to
the idle speed control servo connector.
Terminal 2 4. Connect the positive (+) terminal of a power supply
Iac motor (approximately 6 V) to the terminals No. 2 and No. 5.
Terminal 5

MB991709

5. With the idle speed control servo as shown in the

illustration, connect the negative (ï) terminal of the power
supply to each clip as described in the following steps,
and check whether or not a vibrating feeling (a feeling
of very slight vibration of the stepper motor) is generated
as a result of the activation of the stepper motor.
(1) Connect the negative (ï) terminal of the power supply
to the terminal No. 1 and terminal No. 4.
(2) Connect the negative (ï) terminal of the power supply
to the terminal No. 3 and terminal No. 4.
(3) Connect the negative (ï) terminal of the power supply
to the terminal No. 3 and terminal No. 6.
(4) Connect the negative (ï) terminal of the power supply
to the terminal No. 1 and terminal No. 6.
(5) Connect the negative (ï) terminal of the power supply
to the terminal No. 1 and terminal No. 4.
(6) Repeat the tests in sequence from (5) to (1).
6. If vibration is detected during the test, the stepper motor
can be considered to be normal.

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 13D-104 MPI <4G63> ï On-vehicle Service

PURGE CONTROL SOLENOID VALVE CHECK

Refer to GROUP 17 ï Emission Control System.

EGR CONTROL SOLENOID VALVE CHECK

Refer to GROUP 17 ï Emission Control System.

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