Mitsubishi Grandis. Manual — part 907

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-43

• If code No.C1860 or C1861 is not set and the

pump motor power supply voltage is not normal
when the pump motor operates, the ECU
determines that the pump motor is defective, and
sets this diagnosis code.

PROBABLE CAUSES

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

• Malfunction of the pump motor

• Damaged wiring harness or connector

• Malfunction of the hydraulic unit (integrated with

ABS-ECU)

DIAGNOSIS

STEP 1. MUT-III CAN bus diagnostics

CAUTION

Before connecting or disconnecting the MUT-III,
turn the ignition switch to the "LOCK" (OFF)
position.
(1) Connect MUT-III to the 16-pin diagnosis

connector.

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF)

position.

Q: Is the check result normal?

YES :

Go to Step 3.

NO :

Repair the CAN bus line (Refer to GROUP
54D, CAN bus line Diagnostic flow

P.54D-9

). Then go to Step 2.

STEP 2. Check whether the diagnosis code is
reset.

CAUTION

Before connecting or disconnecting the MUT-III,
turn the ignition switch to the "LOCK" (OFF)
position.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the diagnosis code.
(3) Turn the ignition switch to the "LOCK" (OFF)

position.

(4) Turn the ignition switch to the "ON" position.
(5) Check if the diagnosis code is set.
(6) Turn the ignition switch to the "LOCK" (OFF)

position.

Q: Is code No.C1271 set?

YES :

Go to Step 3.

NO :

The procedure is complete.

AC302297

AC310120

AB

MB991827

16-pin

MB991910

MB991824

AC302297

AC310120

AB

MB991827

16-pin

MB991910

MB991824

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-44

STEP 3. Voltage measurement at ABS-ECU
connector A-03.

(1) Disconnect the connector A-03, and connect

special tool ABS Check Harness (MB991974) to
the wiring harness-side connector.
NOTE: Do not connect special tool ABS Check
Harness (MB991974) to the ABS-ECU.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal 14 and

earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 5.

NO :

Go to Step 4.

STEP 4. Check ABS-ECU connector A-03 for
loose, corroded or damaged terminals, or
terminals pushed back in the connector.

Q: Is the check result normal?

YES :

An open or short circuit may be present in

the solenoid valve power supply circuit.
Repair the wiring harness between
ABS-ECU connector A-03 terminal 14 and
fusible link No.4. Then go to Step 8.

NO :

Repair or replace the damaged
component(s). Then go to Step 8.

AC312620AI

Oil reservoir

Connector: A-03

ABS-ECU

MB991974

Check connector

A-03 Harness connector

A-03

Hydraulic unit
(with built-in ABS-ECU)

AC312621

Oil reservoir

Connector: A-03

AC

A-03

Hydraulic unit
(with built-in ABS-ECU)

A-03 Harness connector
(harness side)

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-45

STEP 5. Resistance measurement at ABS-ECU
connector A-03.

(1) Disconnect the connector A-03, and connect

special tool ABS Check Harness (MB991974) to
the wiring harness-side connector.
NOTE: Do not connect special tool ABS Check
Harness (MB991974) to the ABS-ECU.

(2) Measure the resistance between terminal 13 and

earth.

OK: 2 ohm or less

Q: Is the result normal?

YES :

Go to Step 7.

NO :

Go to Step 6.

STEP 6. Check ABS-ECU connector A-03 for
loose, corroded or damaged terminals, or
terminals pushed back in the connector.

Q: Is the result normal?

YES :

An open circuit may be present in the earth

circuit. Repair the wiring harness between
ABS-ECU connector A-03 terminal 13 and
the body earth. Then go to Step 8.

NO :

Repair or replace the damaged
component(s). Then go to Step 8.

AC312620AJ

Oil reservoir

Connector: A-03

ABS-ECU

MB991974

Check connector

A-03 Harness connector

A-03

Hydraulic unit
(with built-in ABS-ECU)

AC312621

Oil reservoir

Connector: A-03

AC

A-03

Hydraulic unit
(with built-in ABS-ECU)

A-03 Harness connector
(harness side)

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-46

STEP 7. Check whether the diagnosis code is
reset.

Check again if the diagnosis code is set.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the diagnosis code.
(3) Turn the ignition switch to the "LOCK" (OFF)

position.

(4) Turn the ignition switch to the "ON" position.
(5) Check if the diagnosis code is set.
(6) Turn the ignition switch to the "LOCK" (OFF)

position.

Q: Is code No.C1271 set?

YES :

Replace the hydraulic unit (integrated with

ABS-ECU). Then go to Step 8.

NO :

It can be assumed that this malfunction is
intermittent. Refer to GROUP 00, How to
Use Troubleshooting/Inspection Service
Points

− How to Cope with Intermittent

Malfunction

P.00-5

.

STEP 8. Check whether the diagnosis code is
reset.

Check again if the diagnosis code is set.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the diagnosis code.
(3) Turn the ignition switch to the "LOCK" (OFF)

position.

(4) Turn the ignition switch to the "ON" position.
(5) Check if the diagnosis code is set.
(6) Turn the ignition switch to the "LOCK" (OFF)

position.

Q: Is code No.C1271 set?

YES :

Go to Step 1.

NO :

The procedure is complete.

AC302297

AC310120

AB

MB991827

16-pin

MB991910

MB991824

AC302297

AC310120

AB

MB991827

16-pin

MB991910

MB991824