Inspection Procedure 9: The stability control/TCL system cannot be disabled when ASC OFF switch is pressed for 3 seconds or more to turn the system OFF.


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

  • ETACS-ECU (ASCS terminal) is earthed by pressing ASC OFF switch. The ON/OFF state of ASC OFF switch is transferred from ETACS-ECU to ASC-ECU via CAN bus line.
  • When the ASC OFF switch is pressed for 3 seconds or more, the ASC system turns OFF.
  • When the ASC OFF switch is pressed and held for 15 seconds or more, ASC turns ON.

COMMENTS ON TROUBLE SYMPTOM
This may be caused by the open and short circuit in the ASC OFF switch circuit.

PROBABLE CAUSES

  • Damaged wiring harness and connectors
  • ASC OFF switch malfunction
  • Malfunction of ETACS-ECU

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 step2.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).

STEP 2. M.U.T.-III data list for other system
Check the ETACS-ECU system data list.

  • ASC OFF switch: During ON operation
Item No.
 Item name
 Normal condition
281
 ASC/TCL OFF switch
 ON

Q. Is the check result normal?
Go to Step 3
Refer to GROUP 54A - ETACS, Inspection Procedure 15 "The ASC OFF switch signal is not received." .

STEP 3. Retest the system.

Q. Does ASC turn ON and OFF normally using ASC OFF switch?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunction ).
Replace the ETACS-ECU (Refer to GROUP 54A - ETACS-ECU ). Then go to Step 4.

STEP 4. Retest the system.

Q. Does ASC turn ON and OFF normally using ASC OFF switch?
This diagnosis is complete.
Return to Step 1.