Mitsubishi Outlander GS45X. Manual — part 382

ABS DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-149

SYMPTOM CHART

M1352011401582

CAUTION

• ABS may operate in the following conditions without hard braking: Slippery road surface,

high-speed turn, and bumpy road surface. When asking the customers, confirm that they
have/have not encountered ABS operation in corresponding conditions.

• During ABS operation, the brake pedal is pulled forward gradually, and noise occurs at the same

time. This is because the brake line pressure varies intermittently to prevent the wheel lock, and
not a system malfunction.

• During diagnosis, a diagnostic trouble code associated with other system may be set when the

ignition switch is turned on with connector(s) disconnected. On completion, check all systems for
diagnostic trouble code(s). If diagnostic trouble code(s) are set, erase them all.

Symptoms

Inspection
procedure
No.

Reference
page

Scan tool cannot communicate only with ABS-ECU.

1

P.35B-150

Brake warning light stays ON with the parking brake lever released.

2

P.35B-151

ABS warning light does not illuminate when ignition switch is turned to the ON
position (Engine stopped).

3

P.35B-157

Brake warning light does not illuminate when the ignition switch is turned to
ON position (Engine stopped).

4

P.35B-159

ABS warning light stays ON after the engine is started.

5

P.35B-161

Abnormality in brake operation

6

P.35B-163

ABS system inoperative

7

P.35B-163

ABS-ECU power supply circuit system

8

P.35B-165

ABS operate too frequently.

9

P.35B-175

The initial check sound of hydraulic unit is loud.

10

P.35B-178

ABS DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-150

SYMPTOM PROCEDURES

Inspection Procedure 1: Scan tool cannot communicate only with ABS-ECU.

CAUTION

If there is any problem in the CAN bus lines, an incorrect
diagnostic trouble code may be set. Prior to this diagno-
sis, diagnose the CAN bus lines (Refer to GROUP 54C

−

CAN Bus Line Diagnostic Flow

P.54C-10

).

.

TECHNICAL DESCRIPTION (COMMENT)

When scan tool cannot communicate with the ABS system, the
CAN bus line, ABS-ECU power supply circuit system, or
ABS-ECU may be faulty.

.

TROUBLESHOOTING HINTS (THE MOST LIKELY
CAUSES FOR THIS CASE:)

• Damaged wiring harness and connectors

• ABS-ECU malfunction

• Wrong routing of M.U.T.-III harness

• Abnormality in battery or generator

• Abnormality in power supply voltage to ABS-ECU

• ECU malfunction of other system

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the CAN bus
line.
Use scan tool to diagnose the CAN bus lines.
Q: Is the check result normal?

YES : Check and repair the power supply circuit system

(Refer to

P.35B-165

).

NO : Repair the CAN bus lines (Refer to GROUP 54C

−

CAN Bus Diagnostics Table

P.54C-10

).

ABS DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-151

Inspection Procedure 2: Brake warning light stays ON with the parking brake lever released.

Brake Warning Light Circuit

CPU

INTERFACE
CIRCUIT

LCD

CAN
TRANSCEIVER
CIRCUIT

INTERFACE
CIRCUIT

LED DRIVE
CIRCUIT

COMBINATION
METER

CAN DRIVE
CIRCUIT

INTERFACE
CIRCUIT

ETACS-
ECU

JOINT
CONNECTOR
(CAN1)

BRAKE
FLUID
LEVEL
SWITCH

PARKING
BRAKE
SWITCH

FUEL WARNING/OIL
PRESSURE WARNING

ACA02742

ABS DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-152

CAUTION

• If there is any problem in the CAN bus lines, an incor-

rect DTC may be set. Prior to this diagnosis, diagnose
the CAN bus lines (Refer to GROUP 54C

− CAN Bus

Line Diagnostic Flow

P.54C-10

).

• Whenever ECU is replaced, ensure that the CAN bus

lines are normal.

.

OPERATION

• When the parking brake switch is turned ON, the combina-

tion meter terminal No. 4 is grounded, and then the brake
warning light illuminates.

• When reduction of the brake fluid amount is detected, the

brake fluid level switch is turned from ON to OFF.
ETACS-ECU monitors the brake fluid level switch, and
instructs the combination meter via the CAN bus line to illu-
minate the brake warning light.

.

AC901112

Connector: A-09

AM

A-09 (B)

AC901075 AC

Connector: C-03

AC901076AG

Connector: C-22

AC702828AE

Connector: C-312

AC901079

Connector: D-125

AY

D-125 (B)