Mitsubishi Outlander XL. Manual - part 643

Brake Fluid Level Switch and Parking Brake Switch Circuit

INTERFACE
CIRCUIT

CAN DRIVE
CIRCUIT

IG1
RELAY

ETACS-
ECU

BRAKE FLUID
LEVEL SWITCH

INTERFACE
CIRCUIT

INTERFACE
CIRCUIT

CPU

CAN 
TRANSCEIVER 
CIRCUIT

LED DRIVE 
CIRCUIT

COMBINATION
METER

PARKING BRAKE
SWITCH

LCD

FUEL WARNING/OIL 
PRESSURE 
WARNING

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-135

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

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. M.U.T.-III CAN bus diagnostics
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 54D - CAN

Bus Diagnostics table P.54D-17.)

STEP 2. M.U.T.-III 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.35C-11.)

NO:

 Go to Step 3.

STEP 3. M.U.T.-III 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, and then go to

Step 5.

NO:

 Go to Step 4.

35B-136

ANTI-LOCK BRAKING SYSTEM (ABS)

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

STEP 4. M.U.T.-III 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:

 Troubleshoot the ETACS, and then go to Step 5.

NO:

 Replace the ABS-ECU, and then go to Step 5.

STEP 5. Retest the system.

Q:Does the ABS warning light turn ON and OFF normally?

YES:

 The procedure is complete.

NO:

 Return to Step 1.

Inspection Procedure 6: Abnormality in Brake Operation

M13502000160USA0000010000

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.35C-188.

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.

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.

M13502000953USA0000010000

TECHNICAL DESCRIPTION (COMMENT)
In case of this trouble symptom, ABS system operation may be
disabled. Diagnostic trouble code may be set by the ABS system
using scan tool.

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-137

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

PROBABLE CAUSES

｠

Low battery voltage

｠

Wiring harness or connector failure of CAN bus line

｠

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. Hydraulic unit (HU) check
Refer to P.35C-188.

Q:Is the check result normal?

YES:

 Go to Step 2.

NO:

 Repair the brake pipe or replace ABS-ECU.

STEP 2. Operation check

Q:Does TCL/ASC operate normally?

YES:

 The procedure is complete.

NO:

 Check the brake system related components except the

ABS system.

35B-138

ANTI-LOCK BRAKING SYSTEM (ABS)

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS