Inspection Procedure 14: The ASC OFF switch signal is not received.


caution
  • Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.
  • When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in Immobilizer System - How to Register Key ID .)

COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES



  • Malfunction of the ASC OFF switch
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE


STEP 1. Check the ASC OFF switch.



Q. Is the check result normal?





STEP 2. Resistance measurement at ASC OFF switch connector (earth terminal)


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the resistance between the ASC OFF switch connector (earth terminal) and body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?





STEP 3. Check of open circuit in earth line between ASC OFF switch connector and body earth


Q. Is the check result normal?





STEP 4. Check of short to power supply, short to earth, and open circuit in ASCS line between ETACS-ECU connector and ASC OFF switch connector


Q. Is the check result normal?





STEP 5. M.U.T.-III data list




  • Operate the ASC OFF switch.
Item No.
 Item name
 Normal condition
281
 ASC/TCL OFF switch
 OFF to ON (only when switch is operated)
OK: Normal condition is displayed.

Q. Is the check result normal?