Inspection Procedure 6: ASC indicator lamp stays ON after the engine 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.
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 ).

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

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

Control is disabled due to the low voltage

note Due to the abnormality in the supply voltage, the diagnosis code may not be stored even when the ASC lamp illuminates.
Damaged wiring harness and connectors
Malfunction of the combination meter
Malfunction of the hydraulic unit assembly (integrated with ASC-ECU)

DIAGNOSIS PROCEDURE

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

	Go to Step 2.

	Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ). Then go to Step 6.

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

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

	Go to Step 3.

Refer to

	Go to Step 4.

	Diagnose the power supply circuit of the ASC-ECU (Refer to ). Then go to Step 6.

Use M.U.T.-III to check if the diagnosis code is set in the combination meter system.

	Perform troubleshooting for the combination meter (Refer to GROUP 54A - Combination Meter, Troubleshooting ). Then go to Step 6.

	Go to Step 5.

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

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

	This diagnosis is complete.

	Return to Step 1.