Inspection Procedure 16: The LDW 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 LDW switch
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE


STEP 1. Check the LDW switch.



Q. Is the check result normal?





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


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the resistance between the LDW 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 LDW switch connector and body earth


Q. Is the check result normal?





STEP 4. Check of short to earth, and open circuit in LDWS line between LDW switch connector and ETACS-ECU connector


Q. Is the check result normal?





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




  • When the LDW switch is pressed.
Item No.
 Item name
 Normal condition
Item 405
 LDW switch
 ON

  • When the LDW switch is not pressed.
Item No.
 Item name
 Normal condition
Item 405
 LDW switch
 OFF
OK: Normal condition is displayed.

Q. Is the check result normal?