Inspection Procedure 4: The Rear Fog Lamp do not Illuminate Normally.


caution Whenever the ECU is replaced, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.








CIRCUIT OPERATION




  • Tail lamp switch
  • Headlamp switch
  • Fog lamp switch
  • Option coding information

COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES



  • Malfunction of the fog lamp switch
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE


STEP 1. ETACS-ECU coding data check


(1)Operate the M.U.T.-III to read the ETACS-ECU option coding information (Refer to GROUP 00 - Coding Table ).
(2)Check that the "Rear fog lamp" is set to "Present."

Q. Is the check result normal?





STEP 2. Check the operation of the position lamps and the headlamps.



Q. Is the check result normal?





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



Q. Is the diagnosis code set?





STEP 4. M.U.T.-III data list




  • Turn the rear fog lamp switch to ON.
Item No.
 Item name
 Normal condition
Item 231
 Rear fog lamp
 ON
OK: Normal condition is displayed.

Q. Is the check result normal?





STEP 5. Connector check: F-21 rear fog lamp connector <LH drive vehicles> or F-11 rear fog lamp connector <RH drive vehicles>


Q. Is the check result normal?





STEP 6. Check the bulb of the rear fog lamp



Q. Is the check result normal?





STEP 7. Resistance measurement at the F-21 rear fog lamp connector <LH drive vehicles> or F-11 rear fog lamp connector <RH drive vehicles>


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Check the resistance between the lamp connector and body earth.

  • Resistance between F-21 rear fog lamp connector <LH drive vehicles> or F-11 rear fog lamp connector <RH drive vehicles> connector terminal No.1 and body earth
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?





STEP 8. Wiring harness check between the F-21 rear fog lamp connector <LH drive vehicles> or F-11 rear fog lamp connector <RH drive vehicles> terminal No. 1 and the body earth


note Before the wiring harness check, check the intermediate connector F-19 and F-22, and then repair that if necessary.

  • Check the earth wires for open circuit.

Q. Is the check result normal?





STEP 9. Connector check: C-311 ETACS-ECU connector


Q. Is the check result normal?





STEP 10. Wiring harness check between the F-21 rear fog lamp connector <LH drive vehicles> or F-11 rear fog lamp connector <RH drive vehicles> terminal No. 2 and the C-311 ETACS-ECU connector terminal No. 14


note Before the wiring harness check, check the intermediate connector F-19 and F-22, and then repair that if necessary.

  • Check the output lines for open circuit.

Q. Is the check result normal?





STEP 11. Retest the system



Q. Is the check result normal?