1998 MITSUBISHI LANCER EVOLUTION IV air condition

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-9
Code No. 53: Motor relay systemProbable cause
This code is output under any of the following conditions:

No signals are input to the motor monitor when the motor relay is ON (motor
does not run, etc.).

A signal is being input to the motor monitor for 3 sec. or more when the motor
relay is OFF (motor continues running, etc.).

The motor relay is inoperative.
Defective motor relay

Defective harness or connector

Defective hydraulic unit

Defective ABS-ECU
Caution
(1) If the motor relay contacts fuse, the motor continues running even when the ignition switch
is turned OFF. In this case, immediately remove fusible link No. 8 (60 A) or disconnect the
A-22 connector or A-77 motor relay connector of the hydraulic unit. Overloading the motor
results in a rundown battery.
(2) Driving the motor through actuator test runs down the battery. After the test, run the engine
for some while.
OK
Check the trouble symptom.NGCheck and repair the harness between
fusible link No. 8 and motor relay.
OK
Check the trouble symptom.NGCheck and repair the harness between
motor relay and hydraulic unit.
OK
Check the trouble symptom.NGCheck and repair the harness between
motor relay and ABS-ECU motor
monitor terminal No. 49.
OK
Check the motor for operation.NGReplace ABS-ECU.
OK
Check the following connectors:
A-22, A-77, B-25NG
Repair
OK
Check the motor for operation.NGReplace the hydraulic unit.
OK
Measure at A-77 motor relay connector
and B-25 ABS-ECU connector.

Disconnect the connector and
measure at the harness side.

Continuity across the following
terminals
Motor relay ABS-ECU
side side
4–49
OK:ConductingNGCheck the following connectors:
A-77, B-25NG
Repair
OK
Measure at A-77 motor relay connector
and A-22 hydraulic unit connector.

Disconnect the connector and
measure at the harness side.

Continuity across the following
terminals
Motor relay Hydraulic
side unit side
4–12
OK:ConductingNGCheck the following connectors:
A-22, A-77NG
Repair
OK
Measure at A-77 motor relay connec-
tor.

Disconnect the connector and
measure at the harness side.

Voltage across 5 and body ground
OK:Battery voltageNGCheck the following connector:
A-77NG
Repair
Check the motor relay.NGReplace the motor relay.

ABS – Troubleshooting35B-10
Code No. 71: Acceleration sensor (lateral acceleration)
systemProbable cause
This code is output under either of the following conditions:

The output from the acceleration sensor (lateral acceleration) becomes 0.5 V or
less, or 4.5 V or more.

The acceleration sensor (lateral acceleration) harness is open- or short-circuited.
Defective acceleration sensor (lateral acceleration)

Defective harness or connector

Defective ABS-ECU
OK
Check the trouble symptom.NGReplace ABS-ECU.
OK
Check the trouble symptom.NGCheck and repair the harness between
acceleration sensor (lateral accelera-
tion) and ABS-ECU.
OK
Check the trouble symptom.NGCheck and repair the harness between
general-purpose fuse No. 6 and
acceleration sensor (lateral accelera-
tion).
OK
Replace ABS-ECU.
OK
Check the following connector:
B-24NG
Repair
OK
Measure at B-24 ABS-ECU connector.

Connect the connector.

Ignition switch: ON

Voltage across 17 and 18
OK:2.4 – 2.6 V
(horizontal position)NGCheck the following connectors:
B-24, D-32, B-52NG
Repair
NG
Check the harness between accelera-
tion sensor (lateral acceleration) and
ABS-ECU.NG
Repair
OK
Check the trouble symptom.
OK
Check the acceleration sensor (lateral
acceleration). (Refer to P.35B-17.)NG
Replace
(1) NGCheck the following connectors:
D-32, B-49, B-75NG
Repair
Check the following connector:
D-32, B-49, B-75NG
Repair
(2) NG
Measure at D-32 acceleration sensor
(lateral acceleration) connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON
(1) Voltage across 1 and body ground
OK:Battery voltage
(2) Continuity across 3 and body
ground
OK:Conducting

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-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).]

CHASSIS ELECTRICAL – Combination Meters54-29
FUEL GAUGE UNIT FLOAT HEIGHT
Move float and measure the height at point F (A) and at
point E (B) with float arm touching stopper.
Standard value:
Float positionMainSub
Point F16.417.5
Point E122.6134.6
FUEL LEVEL SENSOR (THERMISTOR)
1. Connect a test lamp (12V – 3.4W) to the fuel gauge
unit connector terminal and apply the battery voltage.
2. Condition is good if lamp goes off when the thermistor
is immersed in water and goes on when it is taken out
of water.
ENGINE COOLANT TEMPERATURE GAUGE SIMPLE CHECK
Remove the engine coolant tempara-
ture gauge unit connector.
Connect a test lamp (12 V – 3.4 W)
between the harness side connector
and the earth.
When the ignition switch is turned to
ON, the test lamp illuminates.OKThe needle of the engine coolant tem-
perature gauge moves.NGReplace the engine coolant tempera-
ture gauge.
OK
Replace the engine coolant tempera-
ture gauge unit.
NG
Repair the harness.
Point F
Point E
A
B Stopper
Stopper
Test lamp
(12V – 3.4 W)
Earth
Thermistor
Thermistor
Lamp goes on
Lamp goes off

CHASSIS ELECTRICAL – Hazard Warning Lamp Switch, Clock
ILL
ILL
54-44
HAZARD WARNING LAMP SWITCH, CLOCK
SPECIAL TOOL
ToolNumberNameUse
MB990784Ornament removerAir conditioner panel removal
HAZARD WARNING LAMP SWITCH
REMOVAL AND INSTALLATION
2
1 3
4
Hazard warning lamp switch
removal steps
1. Air conditioner panel
2. Switch holder
3. Hazard warning lamp switchClock removal steps
1. Air conditioner panel
4. Clock
INSPECTION
HAZARD WARNING LAMP SWITCH CONTINUITY
CHECK
Switch
iti
Terminal No.
position1245679–10
OFF
ON