Inspection Procedure 12

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

CAUTION:

- If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines CAN Bus Line Diagnostics Flow ).
- 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 steering wheel sensor, the G and yaw rate sensor and brake fluid pressure sensor (Refer to Testing and Inspection , Testing and Inspection and Testing and Inspection ).

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.

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

STEP 1. DTC check

Use scan tool to check the DTC for the ASC system (Refer to Active Stability Control System (ASC)).

Q. Is the check result normal?

YES Go to Step 2.
NO Carry out the diagnosis for the DTC (Refer to Active Stability Control System (ASC)).
STEP 2. Engine control module coding data check

Using scan tool, check if any abnormality is present to the coding data below which are stored in the engine control module Programming and Relearning).

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 Removal and Replacement).
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 Testing and Inspection).

Q. Is the check result normal?

YES Replace the hydraulic unit (integrated with ASC-ECU) (Refer to Testing and Inspection). 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).
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.