Mitsubishi Outlander GS45X. Manual - part 385

ABS DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-161

Inspection Procedure 5: ABS warning light stays ON after the engine is started.

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.

.

SYSTEM OPERATION

• ABS-ECU sends the illumination request signal of the ABS 

warning light to the combination meter through 
ETACS-ECU via CAN communication.

• ABS-ECU illuminates the ABS warning light via 

ETACS-ECU for approximately 3 seconds for valve check 
with the ignition switch turned to the ON position.

.

TECHNICAL DESCRIPTION (COMMENT)

This may be caused by faults in the CAN bus line, 
ETACS-ECU, combination meter or ABS-ECU.

.

PROBABLE CAUSES

• Damaged wiring harness and connectors

• Malfunction of ETACS-ECU

• Combination meter malfunction

• ABS-ECU malfunction

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 : Go to Step 2.
NO :  Repair the CAN bus lines (Refer to GROUP 54C 

− 

CAN Bus Diagnostics Table 

P.54C-10

). Then go to 

Step 6.

STEP 2. Scan tool diagnostic trouble code
Use scan tool to check the diagnostic trouble code for the ABS 
system.
Q: Is the diagnostic trouble code set?

YES : Carry out the diagnosis for the diagnostic trouble 

code (Refer to 

P.35B-15

).

NO :  Go to Step 3.

ABS DIAGNOSIS

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ANTI-LOCK BRAKING SYSTEM (ABS)

35B-162

STEP 3. Scan tool other system diagnostic trouble code
Using scan tool, check that the diagnostic trouble code U0141 
is not set by the combination meter system.
Q: Is any DTC set?

YES : Troubleshoot the combination meter (Refer to 

GROUP 54A 

− Combination Meter/DTC 

P.54A-53

), 

then go to Step 6.

NO :  Go to Step 4.

STEP 4. Scan tool other system diagnostic trouble code
Using scan tool, check that the diagnostic trouble code U0121 
is not set by the ETACS system.
Q: Is any DTC set?

YES : Perform troubleshooting on ETACS-ECU (Refer to 

GROUP 54A 

− ETACS/DTC 

P.54A-741

). Then go to 

Step 6.

NO :  Go to Step 5.

STEP 5. Retest the system.
Drive the vehicle more at 6 mph (10 km/h) or high.
Q: Does the ABS warning light turn ON and OFF normally?

YES : Intermittent malfunction (Refer to GROUP 00 

− How 

to Use Troubleshooting/How to Cope with Intermittent 
Malfunctions 

P.00-15

).

NO :  Replace the hydraulic unit (integrated with ABS-ECU) 

(Refer to 

P.35B-188

). Then go to Step 6.

STEP 6. Retest the system.
Drive the vehicle more at 6 mph (10 km/h) or high.
Q: Does the ABS warning light turn ON and OFF normally?

YES : The procedure is complete.
NO :  Return to Step 1.

ABS DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-163

Inspection Procedure 6: Abnormality in brake operation

.

TECHNICAL DESCRIPTION (COMMENT)

• Although the cause of the trouble cannot be clearly 

resolved since it depends on the running status and road 
surface condition, the malfunction of the hydraulic circuit 
may occur if any diagnostic trouble code is not detected.

.

PROBABLE CAUSES

• Hydraulic unit (HU) malfunction

DIAGNOSIS

STEP 1. Hydraulic unit (HU) check
Refer to 

P.35B-184

.

Q: Is the check result normal?

YES : Go to Step 2.
NO :  Connect the brake tubes correctly, repair the external 

brake lines, or replace the hydraulic unit (integrated 
with ABS-ECU) (Refer to 

P.35B-188

).

STEP 2. Retest the system.
Q: Can any fault be found with the brake operation?

YES : Check the brake system related components except 

ABS.

NO :  The procedure is complete.

Inspection Procedure 7: ABS system inoperative.

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)

In case of this trouble symptom, ABS system operation may be 
disabled. Diagnostic trouble code may be set by the ABS sys-
tem using scan tool.

.

PROBABLE CAUSES

• Low battery voltage

• Wiring harness or connector failure of CAN bus line

• ABS-ECU malfunction

ABS DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-164

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 : Go to Step 2.
NO :  Repair the CAN bus lines (Refer to GROUP 54C 

− 

CAN Bus Diagnostics Table 

P.54C-10

). On 

completion, go to Step 2.

STEP 2. Diagnostic trouble code check after resetting CAN 
bus lines
Q: Is any DTC set?

YES : Carry out the relevant troubleshooting (Refer to 

P.35B-15

).

NO :  Go to Step 3.

STEP 3. Hydraulic unit (HU) check
Refer to 

P.35B-184

.

Q: Is the check result normal?

YES : Go to Step 4.
NO :  Repair the brake pipe or replace hydraulic unit 

(integrated with ABS-ECU) (Refer to 

P.35B-188

).

STEP 4. Operation check
Q: Does ABS operate normally?

YES : The procedure is complete.
NO :  Check the brake system related components except 

the ABS system.