Inspection Procedure 6: ASC warning lamp stays ON after the electric motor unit is started.

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.

OPERATION

ASC-ECU sends the illumination request signal of the ASC warning lamp to the combination meter through the CAN communication.

COMMENTS ON TROUBLE SYMPTOM

This may be caused by faults in the CAN bus line, combination meter or ASC-ECU.

PROBABLE CAUSES

Damaged wiring harness and connectors
Malfunction of ETACS-ECU
Combination meter malfunction

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnosis

Use M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

	Go to Step 2.

	Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ). Then go to Step 6.

STEP 2. M.U.T.-III diagnosis code

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

Q. Is the diagnosis code set?

	Carry out the diagnosis for the diagnosis code (Refer to ).

	Go to Step 3.

STEP 3. Actuator test

Perform the following actuator test by the combination meter system, and check if the ASC warning lamp illuminates (Refer to GROUP 54A - Combination Meter/Actuator Test Table

Item No.07: Indicator 1

Q. Is the check result normal?

	Go to Step 5.

	Diagnose the combination meter (Refer to GROUP 54A - Combination Meter/Trouble Symptom Chart ). Then go to Step 4.

STEP 4. M.U.T.-III other system diagnosis code

Using M.U.T.-III, check that diagnosis code the combination meter system.

Q. Is the diagnosis code set?

	Diagnose the combination meter (Refer to GROUP 54A - Combination Meter/Diagnosis Code ). Then go to Step 6.

	Go to Step 5.

STEP 5. Retest the system.

Q. Does the ASC warning lamp turn ON and OFF normally?

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions .)

	Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ), and then go to Step 6.

STEP 6. Retest the system.

Q. Does the ASC warning lamp turn ON and OFF normally?

	This diagnosis is complete.

	Return to Step 1.