Inspection Procedure 3: The headlamps (low-beam) illuminate regardless of the lighting switch positions. (High-beam does not illuminate)


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 .)
  • When the LDW-ECU is replaced, always initialise the LDW camera (Refer to ) and adjust the LDW camera image (Refer to ).

COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES



  • Malfunction of column switch
  • Malfunction of the photo sensor <Vehicles without lighting control sensor or vehicles without LDW>
  • Malfunction of the lighting control sensor <Vehicles with lighting control sensor>
  • Malfunction of the LDW (light sensor) <Vehicles with LDW>
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE


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



Q. Is the check result normal?





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



Q. Is the diagnosis code set?





STEP 3. M.U.T.-III other system diagnosis code



Q. Is the diagnosis code set?









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



Q. Is the diagnosis code set?





STEP 5. M.U.T.-III other system diagnosis code



Q. Is the diagnosis code set?





STEP 6. M.U.T.-III data list




  • Turn the lighting switch to the "AUTO" position.
Item No.
 Item name
 Normal condition
Item 348
 Head lamp switch (auto)
 ON
OK: Normal condition is displayed.

Q. Is the check result normal?







STEP 7. Photo sensor <Vehicles without lighting control sensor or vehicles without LDW> or lighting control sensor <Vehicles with lighting control sensor> or LDW-ECU (light sensor) <Vehicles with LDW> check



Q. Is the check result normal?





STEP 8. Retest the system



Q. Is the check result normal?