tires MITSUBISHI LANCER EVOLUTION IV 1998 Workshop Manual

REAR AXLE – Troubleshooting 27-9
Code No. 25: Wrong-diameter tireProbable cause
This code is output if the speed of any one of the four wheels exceeds a specified
level with respect to the average of the four wheel speed sensor outputs when the
steering wheel is in the straight-ahead position and the vehicle speed exceeds 20
km/h. At this time, the warning lamp does not light up.
Defective harness or connector

Defective AYC-ECU

Defective ABS-ECU

OK
Replace ABS-ECU.
NG
Check harness between AYC-ECU
and ABS-ECU.NG
Repair
NG
Replace AYC-ECU.
OK
Check the trouble symptom.
NG
Check the following connectors:
B-24, B-95NG
Repair
OK
Check the trouble symptom.
NO
Measure at B-95 AYC-ECU connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: OK

Turn tire at 1/2 to 1 revolution/sec.

Voltage across 6/7/8/9 and body
ground.
OK:42 mV or more (when mea-
sured with a circuit tester)
120 mV-P or more (when
measured with an oscillo-
scope)OKCheck the following connector:
B-95
YES
Is ABS diagnosis code No. 15 output?YESTroubleshooting
Are correct tires mounted on all four
wheels?NO
Repair
NG
Repair

NG
Check and repair the harness between
speed sensor and AYC-ECU.
OK
Check the trouble symptom.
OK
Check the following connectors:
B-95, B-52, B-17, A-26, A-50, D-04,
D-14, D-19NG
Repair
OK
Check wheel bearing.NG
Replace
NG
Replace AYC-ECU.
OK
Check the trouble symptom.
OK
Check the following connector:
B-95NG
Repair
OK
Check speed sensor output voltage.
(Refer to p. 27-31.)NGCheck speed sensor and rotor.
YES
Check speed sensor for installation.NG
Repair
Are correct tires mounted on all four
wheels?NO
Repair
NG
Replace

REAR AXLE – Troubleshooting 27-21
5. INSPECTION CHART FOR TROUBLE SYMPTOMS
Trouble symptomInspection
procedure No.Ref. page
AYC warning lamp does not light up when the ignition key is turned to “ON” (engine
stationary).127-21
AYC warning lamp remains lit up after the engine has started.227-22
AYC is inoperative.
Unable to start or accelerate on slippery road surfaces.327-22
Rear tires are noisy during low-speed cornering.
Vehicle skews.427-23
6. INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
INSPECTION PROCEDURE 1
AYC warning lamp does not light up when the ignition key
is turned to “ON” (engine stationary).
Probable cause
The lamp power supply circuit is probably open-circuited, lamp bulb is out, or the
circuit between AYC warning lamp and AYC-ECU or AYC-ECU itself is defective.
Blown fuse

AYC warning lamp out

Defective harness or connector

Defective AYC-ECU
NG
Check and repair the harness between
ignition switch (IG
2) and AYC warning
lamp.
OK
Check the trouble symptom.
OK
Replace combination meter.
NG
Check the harness between AYC
warning lamp and AYC-ECU.NG
Repair
OK
Check the trouble symptom.OK
Replace AYC-ECU.
OK
Check the following connectors:
B-96, B-94, B-08NG
Repair
OK
Measure at B-96 AYC-ECU connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Warning lamp when 36 is grounded
to body
OK:Lit upNGCheck the lamp bulb.NG
Replace
Measure at B-08 combination meter
connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Voltage across 48 and body ground
OK:Battery voltageNGCheck the following connectors:
B-08, B-74, B-76NG
Repair

REAR AXLE – Troubleshooting 27-23
INSPECTION PROCEDURE 4
Rear tires are noisy during low-speed cornering.
Probable cause
The hydraulic unit or torque transfer differential is probably defective.
Defective hydraulic unit

Defective torque transfer differential
NOTE
This symptom is limited only when the diagnosis code is correct.
NG
Replace the hydraulic unit.
NG
Replace the torque transfer differential.
Check the trouble symptom.
NG
Replace AYC fluid.
OK
Correct
Check the trouble symptom.NO
Replace the torque transfer differential.
OK
Is foreign matter trapped in the hydrau-
lic line?YES
Repair
Check the AYC for operation.OKCheck the AYC fluid.
NG
Check hydraulic pressure.NGBleed the system of air.

ABS – Troubleshooting35B-4
Code No.15: Wheel speed sensor (abnormal output
signal)Probable cause
This code is output when there is an abnormality in the output signal from any one
of the four wheel speed sensors while driving (except for an open circuit or short
circuit).
The four vehicle tires are of different sizes

Malfunction of wheel speed sensor

Malfunction of wiring harness or connector

Malfunction of ABS-ECU

Malfunction of wheel bearing
OK
Check the harness wire, and repair
if necessary.

Between each wheel speed sensor
and ABS-ECU
OK
Wheel bearing checkNG
Replace the ABS-ECU.
OK
ABS rotor checkNG
RepairOK
Check the trouble symptom.
OK
Check the following connector:
B-24NG
Repair
OK
Check the trouble symptom.
OK
Wheel speed sensor output voltage
check (Refer to P.35B-17.)NGWheel speed sensor checkNG
Replace
YES
Wheel speed sensor installation checkNG
Repair
Are the sizes of all four tires identical?NOEquip the vehicle with tires of identical
sizes.
NG

CHASSIS ELECTRICAL – Headlamp54-34
ON-VEHICLE SERVICE
HEADLAMP AIMING
Bring the vehicle in the following conditions before aiming
the headlamp.

Check the tires for inflation pressure. Pump them up if
necessary to the labeled pressure level.

Set the vehicle unladen on a level floor.

Place one person (approximately 55 kg) on the driver’s
seat.
1. Position the tester so that its converging lens faces the
high-beam lamp ( marked) center to center at a distance
of 3 m from each other.
2. Aim the headlamps to appropriate standard values using
the aiming adjustment screw.
Face the face 3 m apart from each other
Lamp center
16M0001
Horizontal adjustment
Vertical
adjust-
ment

CHASSIS ELECTRICAL – Front Fog Lamp54-39
FRONT FOG LAMP
SERVICE SPECIFICATIONS
ItemsStandard value
Headlamp aiming [Paren-
thesized are allowableVertical direction2° (349 mm) below horizontal line (H)
t
beam axis deviations 10 m
ahead of headlamp.]Horizontal direction3° (524 mm) leftward from vertical line (V)
ON-VEHICLE SERVICE
HEADLAMP AIMING
Bring the vehicle in the following conditions before aiming
the headlamp.

Check the tires for inflation pressure. Pump them up if
necessary to the labeled pressure level.

Set the vehicle unladen on a level floor.

Place one person (approximately 55 kg) on the driver’s
seat.

Maintain an engine speed of 2,000 r/min to keep the
battery in the charged condition.
1. Position the tester so that its converging lens faces the
fog lamp center to center at a distance of 10 m.
NOTE
Measure the center of the fog lamp as shown.
A: 572.5 mm (from the center of the vehicle body)
B: 360 mm
2. Remove the fog lamp bezel, and using the aiming
adjustment screw, aim the fog lamp to the standard value.
NOTE
The horizontal direction is non-adjustable. If the beam
axis deviation exceeds the standard value, check the
fog lamp to determine if it is installed out of position and
correct if necessary.
Face to face 10 m apart from
each other
AAB
Adjusting screw