Mitsubishi Outlander GS45X. Manual — part 454

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-243

Inspection Procedure 11: Abnormality in brake operation

CAUTION

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

rect diagnostic trouble code 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.

• When the hydraulic unit (integrated with ASC-ECU) is

replaced, always carry out the calibration of the steer-
ing wheel sensor, the G and yaw rate sensor and brake
fluid pressure sensor (Refer to

P.35C-282

,

P.35C-283

and

P.35C-284

).

.

TECHNICAL DESCRIPTION (COMMENT)

Although the cause of the trouble cannot be clearly resolved
since it depends on the running status and road surface condi-
tion, the malfunction of the hydraulic circuit may occur if any
diagnostic trouble code is not detected.

.

PROBABLE CAUSES

• Hydraulic unit (Integrated with ASC-ECU) malfunction

• Malfunction of hydraulic circuit

• Malfunction of brake assembly

• Malfunction of brake booster

• Malfunction of master cylinder assembly

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, check the diagnostic
trouble code
Q: Is the check result normal?

YES : Go to Step 2.
NO : Troubleshoot for the relevant diagnostic trouble code

(Refer to

P.35C-18

).

STEP 2. Hydraulic unit (Integrated with ASC-ECU) check
Check that the brake tube is installed to the hydraulic unit (inte-
grated with ASC-ECU) correctly (Refer to

P.35C-277

).

Q: Is the check result normal?

YES : Go to Step 3.
NO : Connect the brake tubes correctly, repair the external

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

P.35C-287

).

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-244

STEP 3. Brake operation check
Perform the following checks.

• Brake pedal check (Refer to GROUP 35A − On-vehicle Ser-

vice/Brake Pedal Check and Adjustment

P.35A-15

).

• Brake booster check (Refer to GROUP 35A − On-vehicle

Service/Brake Booster Operation Check

P.35A-17

).

• Check valve check (Refer to GROUP 35A − On-vehicle Ser-

vice/Check Valve Operation Check

P.35A-19

).

Q: Can any fault be found with the brake operation?

YES : Check the brake-related parts, and repair if

necessary. Then, go to Step 4.

NO : Go to Step 4.

STEP 4. Hydraulic unit check
Perform the following actuator tests (Refer to

P.35C-273

).

• Item No.01: FL wheel ABS drive

• Item No.02: FR wheel ABS drive

• Item No.03: RL wheel ABS drive

• Item No.04: RR wheel ABS drive

• Item No.05: FL wheel TCL drive

• Item No.06: FR wheel TCL drive

• Item No.07: RL wheel TCL drive

• Item No.08: RR wheel TCL drive

Q: Is the check result normal?

YES : The procedure is complete.
NO : Replace the hydraulic unit (integrated with ASC-ECU)

(Refer to

P.35C-287

).

Inspection Procedure 12: ASC system does not operate or faulty ASC operate.

CAUTION

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

rect diagnostic trouble code 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.

• When the hydraulic unit (integrated with ASC-ECU) is

replaced, always carry out the calibration of the steer-
ing wheel sensor, the G and yaw rate sensor and brake
fluid pressure sensor (Refer to

P.42C-10

,

P.35C-283

and

P.35C-284

).

.

COMMENTS ON TROUBLE SYMPTOM

In case of this trouble symptom, ASC system operation may be
disabled. Diagnostic trouble code may be set by the TCL/ASC
system using scan tool.

.

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-245

PROBABLE CAUSES

• Low battery output

• Wiring harness or connector failure of CAN bus line

• ASC-ECU malfunction

• Different ETACS-ECU, abnormal variant coding information

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. DTC check
Use scan tool to check the DTC for the ASC system (Refer to

P.35C-18

).

Q: Is the check result normal?

YES : Go to Step 2.
NO : Carry out the diagnosis for the DTC (Refer to

P.35C-18

).

STEP 2. Engine control module coding data check
Using scan tool, check if any abnormality is present to the cod-
ing data below which are stored in the engine control module
(Refer to GROUP 00

− Precautions before Service/Coding List

P.00-44

).

A.S.C.

OK: Available

Q: Is the check result normal?

YES : Go to Step 4.
NO : Go to Step 3.

STEP 3. Engine control module coding data check
Perform the variant coding to the Engine control module.
Q: Is the check result normal?

YES : Go to Step 5.
NO : Replace the engine control module (Refer to GROUP

13A

− ECM

P.13A-887

<2.4L engine>

− or GROUP

13B

− ECM

P.13B-903

<3.0L engine>). Then go to

Step 5.

STEP 4. Hydraulic unit (integrated with ASC-ECU) check
Check that the brake tube is correctly mounted to the hydraulic
unit (integrated with ASC-ECU) (Refer to

P.35C-277

).

Q: Is the check result normal?

YES : Replace the hydraulic unit (integrated with ASC-ECU)

(Refer to

P.35C-277

). Then go to Step 5.

NO : Connect the brake tubes correctly, and repair or

replace the external brake lines of the hydraulic unit
(integrated with ASC-ECU).

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-246

STEP 5. Operation check
Q: Does skid control/TCL operate normally?

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

than the skid control/TCL system.