Inspection Procedure 11: Abnormality in Active Stability Control System Operation.


caution
  • If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. 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.
  • When the hydraulic unit (integrated with ASTC-ECU) is replaced, always carry out the calibration of the steering wheel sensor and the G and yaw rate sensor.

COMMENTS ON TROUBLE SYMPTOM


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

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. Check the diagnosis code.
Using M.U.T.-III, check the diagnosis code for the ASC system. (Refer to ).

Q. Is the check result normal?
Go to Step 2.
Carry out the diagnosis for the diagnosis code (Refer to ).

STEP 2. Engine-ECU coding data check
Using M.U.T.-III, check if any abnormality is present to the coding data below which are stored in the engine-ECU.
A.S.C.
    OK: Available

Q. Is the check result normal?
Go to Step 3.
Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU) <4G64> or (Refer to GROUP 13B - Engine-ECU) <4D56>. Then go to Step 4.

STEP 3. Hydraulic unit assembly (integrated with ASTC-ECU) check
Check that the brake tube is installed to the hydraulic unit assembly (integrated with ASTC-ECU) correctly.

Q. Is the check result normal?
Replace the hydraulic unit assembly (integrated with ASTC-ECU). Then go to Step 4.
Connect the brake tubes correctly, and repair or replace the external brake lines of the hydraulic unit assembly (integrated with ASTC-ECU).

STEP 4. Operation check

Q. Does active stability control system operation normally?
This diagnosis is complete.
Check the brake system related components other than the stability control/TCL system.