Mitsubishi Colt Ralliart. Manual — part 238

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-44

Code No.C1276: Valve relay system

OPERATION

• The ABS-ECU contains the power supply circuit

(terminal No.24) for the solenoid valve. The sole-
noid valve is energised by the valve relay, which
is incorporated in the ABS-ECU.

• The valve relay, which is incorporated in the

ABS-ECU, is always energising the solenoid
valve unless the initial check is in progress when
the ignition switch is turned on, or the recurrent
system check is in progress.

DIAGNOSIS CODE SET CONDITIONS

These diagnosis codes will be set under the cases
below.

• The ABS-ECU monitors the power supply voltage

to the solenoid valve. If the voltage is lower than
the predetermined value, the ECU sets this diag-
nosis code as a failure in the valve relay circuit.

PROBABLE CAUSES

The most likely causes for these diagnosis codes to
set are:

• Damaged wiring harness or connector

• Malfunction of the hydraulic unit (integrated with

ABS-ECU)

ABS-ECU

SOLENOID
VALVE POWER
SOURCE

MOTOR POWER SOURCE

MOTOR

SOLENOID VALVE

HYDRAULIC UNIT

FUSIBLE
LINK

FUSIBLE
LINK

CHARGING
SYSTEM

3

5

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Gray R : Red P : Pink V : Violet

Hydraulic Unit (Motor and Solenoid Valve) Circuit

Main

Index

Group

TOC

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-45

DIAGNOSIS PROCEDURE

M.U.T.-III diagnosis code

CAUTION

Before connecting or disconnecting the
M.U.T.-III, turn the ignition switch to the "LOCK"
(OFF) position.
(1) Turn the ignition switch to the "ON" position.

(2) Check if the diagnosis code is set.
(3) Turn the ignition switch to the "LOCK" (OFF)

position.

(4) Disconnect M.U.T.-III.

Q: Is code No.C1278 also set?

YES :

Carry out the troubleshooting for diagnosis

code No.C1278 (Refer to

P.35B-46

).

NO :

Replace the hydraulic unit (integrated with
ABS-ECU) (Refer to

P.35B-78

).

AC206895

AC

Diagnosis

connector

MB991827

MB991824

MB991910

Main

Index

Group

TOC

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-46

Code No.C1278: Valve relay system stuck off

OPERATION

• The ABS-ECU contains the power supply circuit

(terminal No.24) for the solenoid valve. The sole-
noid valve is energised by the valve relay, which
is incorporated in the ABS-ECU.

• The valve relay, which is incorporated in the

ABS-ECU, is always energising the solenoid
valve unless the initial check is in progress when
the ignition switch is turned on, or the recurrent
system check is in progress.

DIAGNOSIS CODE SET CONDITIONS

• The ABS-ECU monitors the power supply voltage

to the solenoid valve. If the voltage is lower than
the predetermined value, the ECU sets this diag-
nosis code as a failure in the valve relay circuit.

PROBABLE CAUSES

The most likely causes for these diagnosis codes to
set are:

• Damaged wiring harness or connector

• Malfunction of the hydraulic unit (integrated with

ABS-ECU)

ABS-ECU

SOLENOID
VALVE POWER
SOURCE

MOTOR POWER SOURCE

MOTOR

SOLENOID VALVE

HYDRAULIC UNIT

FUSIBLE
LINK

FUSIBLE
LINK

CHARGING
SYSTEM

3

5

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Gray R : Red P : Pink V : Violet

Hydraulic Unit (Motor and Solenoid Valve) Circuit

Main

Index

Group

TOC

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-47

DIAGNOSIS PROCEDURE

STEP 1. Check ABS-ECU connector A-05 for
loose, corroded or damaged terminals, or
terminals pushed back in the connector.

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Repair or replace the damaged
component(s). Refer to GROUP 00, How to
Use Troubleshooting/Inspection Service
Points

− Connector Inspection Service

Points

P.00-11

.

STEP 2. Resistance measurement at ABS-ECU
connector A-05.

(1) Disconnect the connector A-05, and connect

special tool ABS Check Harness (MB991951) to
the wiring harness-side connector.
NOTE: Do not connect special tool ABS Check
Harness (MB991951) to the ABS-ECU.

(2) Measure the resistance between terminal 24 and

battery terminal.

OK: 10

Ω or less

AC313863AB

Connector: A-05

Harness side

A-05(B)

AC313863AB

Connector: A-05

Harness side

A-05(B)

AC314249AB

ABS-ECU

MB991951

Check connector

A-05 Harness connector

AC313972 BG

Check connector
(Harness side)

Main

Index

Group

TOC