1998 MITSUBISHI LANCER EVOLUTION IV change wheel

MPI – Troubleshooting
Vehicle
speedInitial accel-
erator pedal
depression
NormalHesitation
Sag
Time
(Figure 1)(Figure 2)
Normal
Initial accel-
erator pedal
depression
IdlingStumble
TimeVehicle
speed
13-17
4. PROBLEM SYMPTOMS TABLE
ItemsSymptom
StartingWon’t startThe starter is used to crank the engine, but there is no combustion within the
cylinders, and the engine won’t start.
Fires up and diesThere is combustion within the cylinders, but then the engine soon stalls.
Hard startingEngine starts after cranking a while.
Idling
stabilityRough idle
HuntingEngine speed doesn’t remain constant and changes at 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 or hunting.
Incorrect idle speedThe engine doesn’t idle at the usual correct speed.
Engine stall
(Die out)The engine stalls when the accelerator pedal is released, regardless of whether
the vehicles is moving or not.
Engine stall
(Pass out)The engine stalls when the accelerator pedal is depressed or while it is being
used.
DrivingHesitation, 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 Figure 1.)
Poor accelerationPoor 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.
StumbleEngine speed increase is delayed when the accelerator pedal is initially
depressed for acceleration. (Refer to Figure 2.)
ShockThe feeling of a comparatively large impact or vibration when the engine is
accelerated or decelerated.
SurgeThis is repeated forward or rearward surging during constant speed travel or
during variable speed travel.
KnockingA sharp sound like a hammer striking the cylinder walls during driving and which
adversely affects driving.
StoppingRun on
(“Dieseling”)The condition in which the engine continues to run after the ignition switch is
turned to OFF. Also called “Dieseling”.

REAR AXLE – Troubleshooting 27-12
Code No. 33: Steer sensor (ST-N) systemProbable cause
This code is output when the steering wheel is turned 400 or more in the same
direction with ST-N OFF (HIGH voltage).
Defective steer sensor

Defective harness or connector

Defective AYC-ECU
NG
Replace AYC-ECU.
Check the trouble symptom.
OK
Replace the steer sensor.
NG
Check the harness between steer sen-
sor and AYC-ECU.NG
Repair
OK
Replace AYC-ECU.
OK
Check the trouble symptom.
Measure at B-95 AYC-ECU connector.

Connector connected.

Ignition switch: ON

Turn steering wheel about 90 in
either direction from the straight-
ahead position.

Voltage across 17 and body
ground.
OK:The voltage increases from
about 0.5 V or less to about
3.5 V.NGCheck the following connectors:
B-95, B-65, B-98NG
Repair
Code No. 34: Steer sensor (ST-1, ST-2) systemProbable cause
This code is output if a turning condition is detected for a cumulative period of time
of 15 min. or more, during which there is no change in the steer sensor (ST-1, ST-2)
signals with the wheel speed 15 km/h or more.
Defective steer sensor

Defective harness or connector

Defective AYC-ECU
NG
Replace AYC-ECU.
Check the trouble symptom.
OK
Replace the steer sensor.
NG
Check the harness between steer sen-
sor and AYC-ECU.NG
Repair
OK
Replace AYC-ECU.
OK
Check the trouble symptom.
Measure at B-95 AYC-ECU connector.

Connector connected.

Ignition switch: ON

Voltage across 4/5 and body
ground
OK:The voltage alternates
between about 0.5 V and
about 3 V as the steering
wheel is turned.NGCheck the following connectors:
B-95, B-65, B-98NG
Repair

ABS – Troubleshooting35B-2
The EVOLUTION-V is provided with a lateral acceleration sensor in addition to the longitudinal acceleration
sensor, and the ABS-ECU connector is changed in terminal arrangement. When servicing EVOLUTION-V,
therefore, use the following service procedures.
TROUBLESHOOTING
1. INSPECTION CHART FOR DIAGNOSIS CODES
Diagnosis
code No.Diagnosis itemsReference Page
11Wheel speed sensor (FR) system (open- or short-circuit)35B-3
12Wheel speed sensor (FL) system (open- or short-circuit)35B-3
13Wheel speed sensor (RR) system (open- or short-circuit)35B-3
14Wheel speed sensor (RL) system (open- or short-circuit)35B-3
15Wheel speed sensor system (abnormal output signal)35B-4
16ABS-ECU power supply voltage system (abnormal voltage drop or rise)35B-5
21Wheel speed sensor (FR) system35B-2
22Wheel speed sensor (FL) system35B-2
23Wheel speed sensor (RR) system35B-2
24Wheel speed sensor (RL) system35B-2
27AYC monitor system (detective AYC)35B-6
32Longitudinal acceleration sensor circuit system35B-6
33Stop lamp switch system35B-7
41Solenoid valve (FR) system35B-7
42Solenoid valve (FL) system35B-7
43Solenoid valve (RR) system35B-7
44Solenoid valve (RL) system35B-7
51Valve relay system35B-8
53Motor relay system35B-9
63ABS-ECU failureReplace ABS-ECU.
71Lateral acceleration sensor system35B-10

ABS – Troubleshooting35B-11
3. INSPECTION CHART FOR TROUBLE SYMPTOMS
Get an understanding of the trouble symptoms and check according to the inspection procedure chart.
Trouble symptomsInspection pro-
cedure No.Reference page
When the ignition key is turned to “ON” (engine stopped), the ABS warning lamp
does not illuminate.135B-12
Even after the engine is started, the ABS warning lamp remains illuminated.235B-13
After the ignition key is turned to “ON”, the ABS warning lamp blinks twice, and
when turned to “START”, it illuminates. When returned to “ON”, the lamp
flashes once, and then switches off.335B-13
When the ignition key is turned to “START”, the ABS warning lamp does not
illuminate.435B-14
Brake operation is abnormal535B-14
Caution
(1) If steering movements are made when driving at high speed, or when driving on road surfaces
with low frictional resistance, or when passing over bumps, the ABS may operate even though
sudden braking is not being applied. Because of this, when getting information from the customer,
check if the problem occurred while driving under such conditions as these.
(2) During ABS operation, the brake pedal may vibrate or may not be able to be depressed. Such
phenomena are due to intermittent changes in hydraulic pressure inside the brake line to prevent
the wheels from locking and is not an abnormality.