Inspection Procedure 10: 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 ASC-ECU) is replaced, always carry out the calibration of the G and yaw rate sensor and the steering wheel sensor (Refer to and ).

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

Low battery voltage
The CAN bus line is defective.
Engine coding data problem
Malfunction of the hydraulic unit assembly (integrated with ASC-ECU)
Different ETACS-ECU, abnormal variant coding information

DIAGNOSIS PROCEDURE

STEP 1. Check the diagnosis code.

Using M.U.T.-III, check the diagnosis code for the ASC system.

Q. Is the check result normal?

	Go to Step 2.

	Carry out the diagnosis for the diagnosis code (Refer to ). Then go to Step 6.

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. (Refer to GROUP 00 - Coding Reference Table

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). Then go to Step 6.

STEP 3. Hydraulic unit (integrated with ASC-ECU) check.

Check that the brake tube is installed to the hydraulic unit (integrated with ASC-ECU) correctly. (Refer to

Q. Is the check result normal?

	Go to Step 4.

	Connect the brake tubes correctly, and repair or replace the external brake lines of the hydraulic unit (integrated with ASC-ECU). Then go to Step 6.

STEP 4. Operation check.

Q. Does stability control/TCL operate normally?

	The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction).

	Check the brake system related components other than the stability control/TCL system. Then go to Step 5.

STEP 5. Operation check.

Q. Does stability control/TCL operate normally?

	Replace the hydraulic unit assembly (integrated with ASC-ECU) (Refer to ). Then go to Step 6.

	This diagnosis is complete.

STEP 6. Operation check.

Q. Does stability control/TCL operate normally?

	This diagnosis is complete.

	Return to Step 1.