1999 MITSUBISHI LANCER EVOLUTION VI Throttle body

MPI – Troubleshooting13-27
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
idling is too small.
Malfunction of the ISC servo system

Malfunction of the throttle body
MUT-II Self-Diag code
Are diagnosis codes displayed?Ye sRefer to P.13-8, INSPECTION CHART FOR DIAGNOSIS CODES.
No
Check the ISC servo for operation sound.NGCheck the ISC servo system.
(Refer to P.13-44, INSPECTION PROCEDURE 33.)
OK
MUT-II Data list
26 Idle position switch (Refer to P.13-58.)NGCheck the idle position switch system.
(Refer to P.13-38, INSPECTION PROCEDURE 26.)
OK
MUT-II Data list
21 Engine coolant temperature sensor (Refer to P.13-57.)NGCheck the engine coolant temperature sensor system.
(Refer to P.13-10, INSPECTION PROCEDURE FOR DIAGNOSIS
CODE 21.)
OK
Basic idle speed adjustment (Refer to P.13-30.)*
Check trouble symptom.NGClean the throttle valve area.
Adjust the fixed SAS. (Refer to P.13-30.)*
NOTE
*: Refer to Workshop Manual for LANCER EVOLUTION-IV and EVOLUTION-V (Pub. No. S9806CNCP9).

MPI – Troubleshooting13-28
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 probably that the air/fuel mixture is inappropriate
when the engine is cold, or that the intake air volume is insufficient.
Malfunction of the ISC servo system

Malfunction of the throttle body

Malfunction of the injector system

Malfunction of the ignition system
Were the battery terminals disconnected recently?Ye sAfter warming-up, let the engine run at idling for about 10 minutes.
No
MUT-II Self-Diag code
Are diagnosis codes displayed?Ye sRefer to P.13-8, INSPECTION CHART FOR DIAGNOSIS CODES.
OK
Check the fuel pressure. (Refer to P.13-30.)*
OK
Check the ignition timing.
(Refer to GROUP 11 – Engine Adjustments.)*NGCheck that the crank angle sensor and the timing belt cover are
installed properly.
OK
Check the following items.

Check the ignition coil, spark plugs, spark plug cables.

Check the compression pressure.

Check the engine oil viscosity.
OK
MUT-II Data list
26 Idle position switch (Refer to P.13-58.)NGCheck the idle position switch system.
(Refer to P.13-38, INSPECTION PROCEDURE 26.)
OK
Check the injector for operation sound.NGCheck the injector system. (Refer to P.13-15, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
Ye s
Check the ISC servo for operation sound.NGCheck the ISC servo system.
(Refer to P.13-44, INSPECTION PROCEDURE 33.)
No
Is engine-idling stable after the warming-up?NoCheck for unstable idling (Rough idling, hunting).
(Refer to P.13-25, INSPECTION PROCEDURE 8.)
No
Does the engine stall right after the accelerator pedal is released?Ye sClean the throttle valve
area.Adjust the fixed SAS.
(Refer to P.13-30.)*
OK
MUT-II Data list
21 Engine coolant temperature sensor (Refer to P.13-57.)NGCheck the engine coolant temperature sensor system.
(Refer to P.13-10, INSPECTION PROCEDURE FOR DIAGNOSIS
CODE 21.)
NOTE
*: Refer to Workshop Manual for LANCER EVOLUTION-IV and EVOLUTION-V (Pub. No. S9806CNCP9).

MPI – Troubleshooting13-48
INSPECTION PROCEDURE 39
MUT-II: Check if uncomplete combustion occurs.
MUT-II Self-Diag code
Are diagnosis codes displayed?Ye sRefer to P.13-8, INSPECTION CHART FOR DIAGNOSIS CODES.
No
MUT-II Actuator test
07 Fuel pump (Refer to P.13-61.)NGCheck the fuel pump system.
(Refer to P.13-36, INSPECTION PROCEDURE 25.)
OK
MUT-II Data list
21 Engine coolant temperature sensor (Refer to P.13-57.)NGCheck the engine coolant temperature sensor system.
(Refer to P.13-10, INSPECTION PROCEDURES FOR DIAGNOSIS
CODE 21.)
OK
MUT-II Data list
18 Ignition switch-ST (Refer to P.13-57.)NGCheck the ignition switch-ST system.
(Refer to P.13-38, INSPECTION PROCEDURE 27.)
INSPECTION PROCEDURE 40
Check if hunting occurs.
Clean the throttle body.
Check and adjust the fixed SAS. (Refer to P.13-30.)*
Check trouble symptom.
NG
Inspect the intake of air into the air intake system

Broken intake manifold gasket

Broken air intake hose

Broken vacuum hose

Positive crankcase ventilation valve does not operate.
NOTE
*: Refer to Workshop Manual for LANCER EVOLUTION-IV and EVOLUTION-V (Pub. No. S9806CNCP9).

MPI – Troubleshooting13-67
RESISTANCE AND CONTINUITY BETWEEN HARNESS SIDE CONNECTORS AND TERMINALS
Engine-ECU Harness Side Connector Terminal Arrangement
Terminal No.Inspection itemNormal condition (Check condition)
1 – 12No.1 injector2 – 3 Ω (At 20C)
14 – 12No.2 injector
2 – 12No.3 injector
15 – 12No.4 injector
3 – 12Fuel pressure control valve28 – 36 Ω (At 20C)
4 – 12Stepper motor coil (A1)28 – 33 Ω (At 20C)
17 – 12Stepper motor coil (A2)
5 – 12Stepper motor coil (B1)
18 – 12Stepper motor coil (B2)
6 – 12Secondary air control solenoid valve28 – 36 Ω (At 20C)
11 – 12Wastegate solenoid valve62 – 74 Ω (At 20C)
60 – 12Oxygen sensor heater
11 – 18 Ω (at 20C)
13 – Body earthEngine-ECU earthContinuity established (0 Ω)
26 – Body earth
72 – 92Intake air temperature sensor5.3 – 6.7 kΩ (When intake air temperature is 0C)
2.3 – 3.0 kΩ (When intake air temperature is 20C)
1.0 – 1.5 kΩ (When intake air temperature is 40C)
0.30 – 0.42 kΩ (When intake air temperature is 80C)
74 – 77High temperature sensor3 Ω or less
83 – 92Engine coolant temperature sensor5.1 – 6.5 kΩ (When coolant temperature is 0C)
2.1 – 2.7 kΩ (When coolant temperature is 20C)
0.9 – 1.3 kΩ (When coolant temperature is 40C)
0.26 – 0.36 kΩ (When coolant temperature is 80C)
87 – 92Idle position switchContinuity established (when throttle valve is at idle
position)
No continuity (when throttle valve is slightly open)
91 – Body earth–Continuity established

REAR AXLE – Troubleshooting 27-12
Code No. 41: TPS systemProbable cause
This code is output when the input from the throttle position sensor falls short of
0.2 V.
Defective TPS

Defective harness or connector

Defective AYC-ECU
OK
Replace AYC-ECU.
NG
Check and repair the harness between
AYC-ECU and TPS.
OK
Check the trouble symptom.
NO
Measure at B-95 AYC-ECU connector.

Connector connected.

Ignition switch: ON

Voltage across 18 and body ground

Fully open the throttle valve.
OK:4.5 – 5.0 VNGCheck the following connector:
B-95
Is the MPI diagnosis code No. 14 out-
put?YESRefer to GROUP 13A TROUBLE-
SHOOTING.
NG
Repair
Code No. 51: Longitudinal acceleration sensor systemProbable cause
Code No. 56: Lateral acceleration sensor system
This code is output when the output from the acceleration sensor becomes 0.5 V
or less or 4.5 V or more.
Defective longitudinal acceleration sensor

Defective lateral acceleration sensor

Defective harness or connector

Defective AYC-ECU
NG
Replace the acceleration sensor.
OK
Check the trouble symptom.
OK
Check and repair the harness between
acceleration sensor and ignition
switch.
OK
Check the trouble symptom.
NG
Check and repair the harness between
acceleration sensor and AYC-ECU.
NGReplace AYC-ECU.
OK
Check the following connectors:
D-20, D-32
OK
Check the trouble symptom.
OK
Check the trouble symptom.
NG: 4.5 V or more
Check the acceleration sensor. (Refer
to P.27-42.)NG
Replace
NG: 0.5 V or less
Check at D-20, D-32 acceleration sen-
sor connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Voltage across 1 and body ground
OK:System voltageNGCheck the following connectors:
D-20, D-32, B-49, B-75, B-76NG
Check and repair the harness between
acceleration sensor and AYC-ECU.
NG
Measure at D-20, D-32 acceleration
sensor connector.

Connector connected.

Ignition switch: ON

Voltage across 2 and body ground
OK:0.5 – 4.5 VOKCheck the following connectors:
D-20, D-32NG
Repair
Measure at B-95 AYC-ECU connector.

Connector connected.

Ignition switch: ON

Voltage across 1/3 and body
ground
OK:0.5 – 4.5 VOKCheck the following connector:
B-95NG
Repair
NG
Replace