1998 MITSUBISHI LANCER EVOLUTION IV ESP

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 27-19
Code No. 82: Electric pump systemProbable cause
This code is output if the pressure switch is not set to high-pressure position despite
the AYC-ECU’s command to drive the AYC relay for a given period of time.
Low hydraulic oil level

Oil leak

Defective fusible link

Defective AYC relay

Defective harness or connector

Defective AYC motor

Defective accumulator pressure switch

Defective AYC-ECU
OK
Replace AYC-ECU.
Check the harness
between AYC relay and
AYC motor, and between
AYC motor and body
ground.NG
Replace
NG
OK
Check the trouble symptom.
OK
Check the following
connectors:
A-126, B-94, B-27, F-32NG
Repair
OK
Replace AYC-ECU.
NG
Check the harness
between AYC-ECU and
accumulator pressure
switch.NG
Repair
NG
Check and repair the har-
ness between fusible link
no. 10 and AYC relay.
OK
Check the trouble symp-
tom.
OK
Replace the hydraulic unit
for a defective accumula-
tor pressure switch.
NO
Repair the leak.
OK
Check the trouble symptom.
NG
Check the following
connector: A-126NG
Repair
YES
Add hydraulic oil.
Is the hydraulic oil level correct in the reservoir tank?
(Refer to P.27-29.)NOIs there a hydraulic oil leak?
Measure at A-126 AYC relay connector.

Disconnect the connector and measure at the harness side.

Voltage across 5 and body ground
OK: Battery voltage
NG
NO
Can pump be operated?YESMeasure at F-31 accumulator pressure switch connector.

Disconnect the connector and measure at the harness side.

Ignition switch: ON

Voltage across 2 and body ground
OK:Battery voltage
YES
Is diagnosis code no. 81 output?YESCheck the AYC relay system. (Refer to P.27-18.)
NG
Check the following
connectors: B-95, B-94,
D-06, F-30, F-31NG
Repair
OK

Check AYC relay for
continuity.
(Refer to P.27-52.)

Check AYC motor for
operation.NG
Repair

REAR AXLE – Troubleshooting 27-20
Code No. 83: Electric pump systemProbable cause
This code is output if the pressure switch is not set to low-pressure position despite
the AYC-ECU’s command to change the driving force.
Defective accumulator pressure switch

Defective harness or connector
OK
Replace AYC-ECU.
NG
Check the harness between AYC-ECU
and accumulator pressure switch.NG
Repair
OK
Check the trouble symptom.
NG
Check and repair the harness between
accumulator pressure switch and body
ground.
OK
Check the trouble symptom.
(2) NG
Check the following connectors:
F-31, F-30NG
Repair
NO
Measure at F-31 accumulator pressure
switch connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON
(1) Voltage across 2 and body ground
OK:Battery voltage
(2) Continuity across 1 and body
ground
OK:ConductingOKReplace the hydraulic unit for a defec-
tive accumulator pressure switch.
OK
Check and repair the harness between
AYC relay and AYC motor.
NO
Is diagnosis code no. 71, 72, or 73
output?YES
Check the proportioning valve
system (code no. 71).
(Refer to P.27-15.)

Check the directional control valve
(right) system (code no. 72).
(Refer to P.27-16.)

Check the directional control valve
(left) system (code no. 73).
(Refer to P.27-17.)
(1) NGCheck the following connectors:
B-95, B-94, D-06, F-30, F-31NG
Repair
Does the AYC motor continue turning
when the ignition switch is turned ON?YESCheck the AYC relay for continuity.
(Refer to P.27-52.)NG
Repair

REAR AXLE – LSD Case Assembly 27-48
BSCREW TIGHTENING
(1) Align the alignment mark on differential case A with that
on differential case B.
(2) Tighten the screws connecting differential case A and
B a uniform amount little by little in the diagonal order.
NOTE
If tightening the screws does not bring the two cases
properly together, spring plates are not probably
assembled properly. Reassemble from the start.
CLSD DIFFERENTIAL TORQUE CHECK
(1) Using the special tool, check for differential torque.
Standard value:
When new clutch plate is
installed Nm {kgf
m}When existing clutch plate is
reused Nm {kgf
m}
5 – 19 {0.5 – 1.9}2 – 19 {0.2 – 1.9}
NOTE
Before measuring the differential torque, first turn the
gears so they snug each other, then take measurements
during rotation.
(2) If the measurement falls outside the specified range,
disassemble the differential case assembly and repair
or replace defective parts.
INSPECTION
1. DIFFERENTIAL CASE INTERNAL PARTS
CONTACT/SLIDING SURFACE CHECK
(1) Clean the disassembled parts with cleaning oil and dry
them with compressed air.
(2) Check each plate, disc, and pressure ring for the following:
A. Friction and sliding surfaces of friction discs, friction
plates, and spring plates.
Replace a defective part with heat discoloration and
excessive wear with a new one, as it degrades locking
performance.
NOTE
If the inner periphery of the friction face shows traces
of harsh contact, it is because of the spring tension
of each plate, disc and other part. Do not confuse
this with abnormal wear.
B. Inner periphery and outer periphery protrusions of
friction discs, friction plates, and spring plates.
Replace a cracked or damaged part with a new one.
C. Friction and sliding surfaces between pressure rings
and friction discs.
MB990989MB990990
Friction disc
Friction plateSpring plate
Pressure ring

PARKING BRAKE – Parking Brake Cable36-6
REMOVAL SERVICE POINTS
AREAR BRAKE CALIPER ASSEMBLY REMOVAL
Remove the rear brake caliper assembly and support it with
wire or similar.
BSHOE HOLD-DOWN CUP REMOVAL
Extend the shoe and lining assembly, and remove the shoe
hold-down cup.
INSTALLATION SERVICE POINTS
AADJUSTER INSTALLATION
Install the adjuster so that the shoe adjusting bolt of left hand
wheel is attached towards the front of the vehicle, and the
shoe adjusting bolt of right hand wheel is towards the rear
of the vehicle.
BSHOE-TO-ANCHOR SPRING INSTALLATION
Install the shoe-to-anchor springs in the order shown in the
illustration.
Caution
The load on the respective shoe-to-anchor springs is
different, so the spring in the figure has been painted.
NOTE
The figure shows the left wheel; for the right wheel, the position
is symmetrical.
Shoe
hold-down
cup
Shoe adjusting
bolt
Rear
(Painted) 1
2

54-1
CHASSIS
ELECTRICAL
CONTENTS
GENERAL 3. . . . . . . . . . . . . . . . . . . . . . . . . .
BATTERY 3. . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE SPECIFICATION 3. . . . . . . . . . . . . . .
ON-VEHICLE SERVICE 3. . . . . . . . . . . . . . . . . .
IGNITION SWITCH EVOLUTION-VI WITH IMMOBILIZER
SYSTEM> 6. . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOL 6. . . . . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING 6. . . . . . . . . . . . . . . . . . . .
IGNITION SWITCH 11. . . . . . . . . . . . . . . . . . . . . .
IGNITION SWITCH AND IMMOBILIZER
SYSTEM IMMOBILIZER SYSTEM> 13. . . . . . . . . . .
SPECIAL TOOL 13. . . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING 13. . . . . . . . . . . . . . . . . .
IGNITION SWITCH AND IMMOBILIZER
SYSTEM 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COMBINATION METERS 22. . . . . . . . . . . .
SERVICE SPECIFICATIONS 22. . . . . . . . . . . .
SEALANT 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS 23. . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING 24. . . . . . . . . . . . . . . . . .
CONTINUED ON NEXT PAGE
WARNINGS REGARDING SERVICING OF SUPPLEMENTAL RESTRAINT SYSTEM (SRS) EQUIPPED VEHICLES
WARNING!
(1) The service personnel must thoroughly review this manual, and especially its GROUP 52B – Supplemental Restraint
System (SRS) before beginning any service or maintenance of any component of the SRS or any SRS-related
component.
(2) When removing or installing the components indicated in the table of contents by an astarisk (*), use utmost care so
as not to apply any strong shock to SRS components.
NOTE
The SRS includes the following components: SRS-ECU, SRS warning lamp, air bag module, clock spring and interconnecting
wiring. Other SRS-related components (that may have to be removed/installed in connection with SRS service or maintenance) are
indicated in the table of contents by an asterisk (*).