warning MITSUBISHI LANCER EVOLUTION IV 1998 User Guide

REAR AXLE – Troubleshooting <AYC>27-22
INSPECTION PROCEDURE 2
AYC warning lamp remains lit up after the engine has
started.
Probable cause
The AYC warning lamp ON circuit is probably short-circuited.
Defective combination meter

Defective harness (short-circuit)

Defective AYC-ECU
NOTE
This symptom is limited only when AYC-ECU power supply is in normal condition and the diagnosis
code is correct.
OK
Replace combination meter.
NO
Check the harness between AYC
warning lamp and AYC-ECU.NG
Repair
Does the AYC warning lamp goes out
when the B-96 AYC-ECU connector
is disconnected?YESReplace AYC-ECU.
INSPECTION PROCEDURE 3
AYC is inoperative.
Unable to start or accelerate on slippery road surfaces.
Probable cause
The hydraulic oil level is probably low, there is an oil leak, the hydraulic unit is defective,
or the torque transfer differential is defective.
Low hydraulic oil level

Oil leak

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
OK
Check the AYC for operation.OKCheck the AYC fluid.
NG
Add hydraulic oil.
NG
Check hydraulic pressure.NGBleed the system of air.
Check the hydraulic oil level.NGCheck for oil leak.OK
Repair

REAR AXLE – Troubleshooting <AYC>27-25
Terminal
No.Normally Check requirement Check item
18TPSIgnition switch:
ON
Accelerator pedal: Fully closed0.3 – 1.0 V
ON
Accelerator pedal: Fully open4.5 – 5.0 V
23Diagnosis data input/output1 V or less
24Idle position switchIgnition switch:
ON
Accelerator pedal: Fully closed2 V or less
ON
Accelerator pedal: Fully open4.5 – 5.0 V
25Accumulator pressure
switchIgnition switch:
ONAccumulator internal pressure:
Low2 V or less
Accumulator internal pressure:
HighBattery voltage
26ECU groundAt all times0 V
31AYC-ECU power supplyIgnition switch: ONBattery voltage
Ignition switch: OFF0 V
35AYC motor relayIgnition switch:
ON
When motor is energizedBattery voltage
ON
When motor is deenergized2 V or less
36AYC warning lampIgnition switch:
ON
When lamp is OFFBattery voltage
ON
When lamp is ON2 V or less
37Directional control valve
(right)
Ignition switch:
ON
Right clutch: ONBattery voltage
(right)ON
Right clutch: OFF0 V
38Proportioning valveIgnition switch:
ONAYC-ON0 V to battery volt-
age
AYC-OFF0 V
39ECU backup power supplyAt all timesBattery voltage
45Directional control valve
(left)
Ignition switch:
ON
Left clutch: ONBattery voltage
(left)ON
Left clutch: OFF0 V
46ECU groundAt all times0 V
NOTE
*1: Indicates the vehicles with ABS.

REAR AXLE – On-vehicle Service <Vehicles with AYC>27-32
Waveform Observation Points
SymptomProbable causeAction
Waveform amplitude is too small, or no
waveform.Defective speed sensorReplace sensor.
Waveform amplitude varies greatly. (No
problem ifthe smallest amplitude is 100
Excessive axle hub lateral and radial runoutReplace hub.
problem if the smallest amplitude is 100
mV or more)Poor AYC-ECU groundingRepair.
Noise on waveform or disturbed
waveform
Open-circuited sensorReplace sensor.
waveform
Open-circuited harnessRepair harness.
Improperly mounted speed sensorCorrect sensor installation.
Missing or collapsed rotor toothReplace rotor.
Caution
Since the speed sensor cable follows the movement of the front or rear suspension, it may be
open-circuited only when the vehicle is run on rough roads and not on ordinary road. The speed
sensor output voltage waveform should therefore be checked also by rocking the sensor harness
so that driving on rough roads may be simulated.
8. ACTION WHEN BATTERY RUNS OUT
When the engine is started using a booster cable where the
battery has completely run down and you attempt to start
the vehicle without waiting for the battery to recover a certain
charge, the engine can misfire and you just cannot start to
move it. In such cases, charge the battery sufficiently; or,
remove the AYC fusible link from the engine compartment
relay box to make AYC inactive before attempting to start
the vehicle. When the fusible link is removed, the AYC warning
lamp lights up. After the battery has been recharged, fit the
fusible link back again and start the engine to ensure that
the AYC warning lamp is off.AYC fusible link

ABS – Troubleshooting35B-8
Code No. 51: Valve relay systemProbable cause
This code is output under any of the following conditions:

The solenoid valve power is not supplied when ABS-ECU attempts to turn ON
the valve relay as part of the initial check when the ignition switch is turned ON.

The solenoid valve power remains supplied when ABS-ECU attempts to turn OFF
the valve relay as part of the initial check when the ignition switch is turned ON.

The solenoid valve power is not supplied while the valve relay remains ON under
normal conditions.
Defective ABS valve relay

Defective harness or connector

Defective ABS-ECU
NOTE
In the diagnosis code reading by means of the ABS warning lamp, this code is output in addition to
the actual diagnosis code since the valve relay connector is disconnected.
If the ABS warning lamp turns ON even when the spot represented by the diagnosis code output in
addition to this code has been repaired, and if no diagnosis code other than No. 51 is output, then
the valve relay system is probably defective. Make the following checks.
OK
Check the trouble symptom.NGCheck and repair the harness between
general-purpose fuse No. 6 and valve
relay.
NG
Replace the ABS-ECU.
OK
Check the trouble symptom.
OK
Check the trouble symptom.NGCheck and repair the harness between
valve relay and ABS-ECU.
OK
Check the following connectors:
A-76, B-25NG
Repair
OK
Measure at A-76 valve relay connector
and B-25 ABS-ECU connector.

Disconnect the connector and
measure at the harness side.

Continuity across the following
terminals
OK:Conducting
Valve relay ABS-ECU
side side
3–48
5–37NGCheck the following connectors:
A-76, B-25NG
Repair
OK
Check the trouble symptom.NGCheck and repair the harness between
fusible link No. 8 and valve relay.
OK
Measure at A-76 valve relay connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON
(1) Voltage across 6 and body ground
(2) Voltage across 2 and body ground
OK:Battery voltage(1) NGCheck the following connector:
A-76NG
Repair
(2) NG
Check the following connector:
A-76NG
Repair
Check the valve relay.NG
Replace

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.

ABS – Troubleshooting35B-12
4. INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
INSPECTION PROCEDURE 1
When the ignition key is turned to “ON” (engine stopped),
the ABS warning lamp does not illuminate.
Probable cause
The ABS-ECU turns the valve relay ON → OFF → ON for initial checking when
it is powered ON. Accordingly, the ABS warning lamp illuminates twice even if the
circuit between the ABS warning lamp and ABS-ECU is faulty.
The cause may be an open circuit in the lamp power supply circuit, a blown lamp,
an open circuit between the ABS warning lamp and ABS-ECU or between the ABS
warning lamp and the valve relay.
Blown fuse

Burn out ABS warning lamp bulb

Malfunction of wiring harness or connector
OK
Check the trouble symptom.NGReplace the combination meter.
OK
Check the following connectors:
B-08, B-09NG
Repair
OK
Check the trouble symptom.NGCheck the harness wire, and repair
if necessary.

Between ignition switch and ABS
warning lamp
OK
Check the motor for operation.NGCheck the harness wire, and repair
if necessary.

Between ABS warning lamp and
ABS-ECU

Between ABS warning lamp and
valve relay
OK
Check the following connectors:
A-76, B-09, B-52NG
Repair
OK
Measure at the combination meter con-
nector B-09.

Disconnect the connector, and
measure at the combination meter
side connector.

Ignition switch: ON

ABS warning lamp condition when
terminal 12 is grounded.
OK:IlluminatesNGCheck whether the ABS warning lamp
bulb is burnt out.NG
OK
Measure at the combination meter con-
nector B-08.

Disconnect the connector and
measure at the harness side
connector.

Ignition switch: ON

Voltage between 42 and body
ground
OK:Battery voltageNGCheck the following connectors:
B-08, B-75, B-76NG
Repair
Fuse check
General-purpose fuse No.4NGReplace fuse after eliminating the
cause.
Replace the ABS warning lamp bulb.

ABS – Troubleshooting35B-13
INSPECTION PROCEDURE 2
Even after the engine is started, the ABS warning lamp
remains illuminated.
Probable cause
The cause is probably a short-circuit in the ABS warning lamp illumination circuit.
Malfunction of combination meter

Malfunction of ABS-ECU

Malfunction of wiring harness (short circuit)
NOTE
This trouble symptom is limited to cases where ABS-ECU power supply is normal and the diagnosis
code is a normal diagnosis code.
NO
Check the harness wire, and repair if necessary.

Between ABS warning lamp and ABS-ECU

Between ABS warning lamp relay and valve relay
NO

Disconnect the ABS-ECU connector B-25.

Disconnect the valve relay connector A-76.

Ignition switch: ON

Does the ABS warning lamp go off?YESReplace the ABS-ECU.
Does the ABS warning lamp stay illuminated when the connector
B-52 is disconnected and the ignition switch is turned to ON?YESReplace the combination meter.
INSPECTION PROCEDURE 3
After the ignition key is turned to “ON”, the ABS warning
lamp blinks once, and when turned to “START”, it
illuminates. When returned to “ON”, the lamp flashes
once, and then switches off.
Probable cause
The ABS-ECU causes the ABS warning lamp to illuminate during the initial check.
During the initial check, the valve relay turns from off to on, off and back to on again.
If there is an open circuit in the harness between the ABS-ECU and the ABS warning
lamp, the lamp will illuminate only when the valve relay is OFF during valve relay
test, etc.
Malfunction of wiring harness or connector

Malfunction of ABS-ECU
OK
Check the trouble symptom.NGCheck the harness between the com-
bination meter and the ABS-ECU, and
repair if necessary.
OK
Check the trouble symptom.NGReplace the ABS-ECU.
OK
Check the following connector:
B-25NG
Repair
Measure at ABS-ECU connector B-25.

Disconnect the connector and
meeasure at the harness side.

Disconnect valve relay connector
A-76.

Ignition switch: ON

Voltage between 50 and body
ground
OK:Battery voltageNGCheck the following connector:
B-25NG
Repair

ABS – Troubleshooting35B-14
INSPECTION PROCEDURE 4
When the ignition key is turned to “START”, the ABS
warning lamp does not illuminate.
Probable cause
The ABS-ECU is powered through IG2 which is turned off when the ignition key
is in START position. The ABS warning lamp is powered through IG1 which is not
turned off even when the ignition key is in START position. So the cause must be
a defective circuit on valve relay side.
Malfunction of wiring harness or connector

Malfunction of valve relay
OK
Check the trouble symptom.NGCheck the harness between the com-
bination meter and valve relay, and
repair if necessary.
OK
Check the motor for operation.NGCheck the harness between the valve
relay and ground, and repair if neces-
sary.
OK
Check the following connector:
A-76NG
Repair
OK
Measure at valve relay connector A-76.

Disconnect the connector and
measure at the harness side.

Disconnect ABS-ECU connector
B-25.

Ignition switch: ON

Voltage between 3 and body
ground
OK:Battery voltageNGCheck the following connectors
and diode:
A-76, B-26NG
Repair
ABS valve relay check.NGReplace the valve relay.
INSPECTION PROCEDURE 5
Brake operation is abnormal
Probable cause
The varies depending on the driving conditions and the road surface conditions, so
problem diagnosis is difficult. However, if a normal diagnosis code is displayed, carry
out the following inspection.
Improper installation of wheel speed sensor

Incorrect sensor harness contact

Foreign material adhering to wheel speed sensor

Malfunction of wheel speed sensor

Malfunction of wheel bearing

Malfunction of hydraulic unit

Malfunction of ABS-ECU
NG
Repair
Hydraulic unit checkOKWheel speed sensor inspection. [Refer to Inspection Procedure
for “when either of diagnosis codes No. 11 to 14 is output” (P.35B-3).]

ABS – Troubleshooting35B-16
Terminal
No.Normally Check requirement Check item
44Wheel speed (RR) outputVehicle stationary1 V or less
Moving forward slowly0 – 5 V
48Valve relay monitor inputIgnition switch: ON (after initial check)Battery voltage
49Motor relay monitor outputIgnition switch:
ON
When motor is energized0 V
ONWhen motor is deenergizedBattery voltage
50ABS warning lamp outputIgnition switch:
ON
When lamp is offBattery voltage
ONWhen lamp is on0 V
51Solenoid valve IN (RL) outputIgnition switch: ON (after initial check)Battery voltage
52Solenoid valve IN (FR) outputIgnition switch: ON (after initial check)Battery voltage
5-2 LISTING OF RESISTANCE AND CONTINUITY ACROSS CONNECTOR TERMINALS ON
HARNESS SIDE
(1) Measure the resistance and check for continuity with the ignition switch in the ”OFF” position and
ABS-ECU connector disconnected.
(2) Measure the resistance and check for continuity across terminals listed below.
(3) Fig. below shows the arrangement of terminals.
Terminal No.Signal nameNormally
1 – body groundSolenoid valve OUT (FL) output4.04 – 4.54 Ω
2 – body groundSolenoid valve OUT (RR) output4.04 – 4.54 Ω
3 – body groundSolenoid valve IN (RR) output8.04 – 9.04 Ω
7 – 20Wheel speed sensor (FL) input1.4 – 1.8 kΩ
8 – 21Wheel speed sensor (RR) input1.4 – 1.8 kΩ
9 – 22Wheel speed sensor (RL) input1.4 – 1.8 kΩ
10 – 23Wheel speed sensor (FR) input1.4 – 1.8 kΩ
14 – body groundSolenoid valve IN (FL) output8.04 – 9.04 Ω
15 – body groundGroundConducting
25 – body groundGroundConducting
40 – body groundSolenoid valve OUT (RL) output4.04 – 4.54 Ω
41 – body groundSolenoid valve OUT (FR) output4.04 – 4.54 Ω
42 – body groundGroundConducting
48 – body groundValve relay monitor inputConducting
49 – body groundMotor relay monitor inputConducting
51 – body groundSolenoid valve IN (RL) output8.04 – 9.04 Ω
52 – body groundSolenoid valve IN (FR) output8.04 – 9.04 Ω

54-1
CHASSIS
ELECTRICAL
CONTENTS
GENERAL 3. . . . . . . . . . . . . . . . . . . . . . . . . .
BATTERY 3. . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE SPECIFICATION 3. . . . . . . . . . . . . . .
ON-VEHICLE SERVICE 3. . . . . . . . . . . . . . . . . .
IGNITION SWITCH <EXCEPT
EVOLUTION-VI WITH IMMOBILIZER
SYSTEM> 6. . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOL 6. . . . . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING 6. . . . . . . . . . . . . . . . . . . .
IGNITION SWITCH 11. . . . . . . . . . . . . . . . . . . . . .
IGNITION SWITCH AND IMMOBILIZER
SYSTEM <EVOLUTION-VI WITH
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 (*).