Inspection Procedure 11: ASC does not operate or faulty ASC operate.

  • If there is any problem in the CAN bus lines, an incorrect diagnosis code may be stored. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.


In case of this trouble symptom, the stability control/TCL system operation may be disabled. Diagnosis code may be stored in the stability control/TCL system using M.U.T.-III.


  • Low battery output
  • Wiring harness or connector failure of CAN bus line
  • ASC-ECU malfunction


STEP 1. Diagnosis code check

Use M.U.T.-III to check the diagnosis code for the ASC system (Refer to ).

Q. Is the check result normal?

YES : Go to Step 2
Carry out the diagnosis for the diagnosis code (Refer to ).

STEP 2. 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 ).

Q. Is the check result normal?

Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ). Then go to Step 3.
Connect the brake tubes correctly, and repair or replace the external brake lines of the hydraulic unit (integrated with ASC-ECU).

STEP 3. Operation check

Q. Does stability control/TCL operate normally?

This diagnosis is complete.
Check the brake system related components other than the stability control/TCL system.