Inspection Procedure 1: The Front Fog Lamps 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


If the front fog lamps do not illuminate normally, the input signal circuit(s) below or the ETACS-ECU may be defective.

COMMENTS ON TROUBLE SYMPTOM


When the front fog lamps do not illuminate normally, the mentioned input signal circuit(s) or ETACS-ECU may be defective.

PROBABLE CAUSES



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 "Front fog lamp" is set to "Present."

Q. Is the check result normal?

Go to Step 2.

Operate the M.U.T.-III to set the option coding "Front fog lamp" to "Present," and check the trouble symptom.

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


Check that the position lamps and the headlamps illuminate normally.

Q. Is the check result normal?

Go to Step 3.

Check the position lamps and the headlamps (Refer to trouble symptom chart ).

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


Check if diagnosis code is set to the ETACS-ECU.

Q. Is the diagnosis code set?

Troubleshoot the ETACS-ECU. Refer to .

Go to Step 4.

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


Use the ETACS-ECU service data to check the signal related to the operation of front fog lamp function.

Item No.
 Item name
 Normal condition
Item 212
 Front fog lamp
 ON
OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 5.

Troubleshoot the ETACS-ECU. Refer to Inspection Procedure 11 "The column switch signal is not received" .

STEP 5. Connector check: A-14X front fog lamp relay connector


Q. Is the check result normal?

Go to Step 6.

Repair the defective connector.

STEP 6. Check the front fog lamp relay


Refer to .

Q. Is the check result normal?

Go to Step 7.

Replace the front fog lamp relay.

STEP 7. Voltage measurement at the A-14X front fog lamp relay connector


(1)Remove the front fog lamp relay, and measure at the relay box side.
(2)Measure the voltage between terminal 3 and the body earth, and between terminal 4 and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 9.

Go to Step 8.

STEP 8. Wiring harness check between the A-14X front fog lamp relay connector terminal No. 2/4 and the fusible link (34)



Q. Is the check result normal?

Go to Step 13.

Repair the wiring harness.

STEP 9. Connector check: C-312 ETACS-ECU connector


Q. Is the check result normal?

Go to Step 10.

Repair the defective connector.

STEP 10. Wiring harness check between the A-14X front fog lamp relay connector terminal No. 1 and the ETACS-ECU connector terminal No. 4



Q. Is the check result normal?

Go to Step 11.

Repair the wiring harness.

STEP 11. Wiring harness check between the A-14X front fog lamp relay connector terminal No. 3 and the A-42 front fog lamp (LH) or A-50 front fog lamp (RH) connector terminal No. 2


note Before the wiring harness check, check the intermediate connector A-46, and then repair that if necessary.

Q. Is the check result normal?

Go to Step 12.

Repair the wiring harness.

STEP 12. Wiring harness check between the A-42 front fog lamp (LH) or A-50 front fog lamp (RH) connector terminal No. 1 and the body earth


note Before the wiring harness check, check the intermediate connector A-46, and then repair that if necessary.

Q. Is the check result normal?

Go to Step 13.

Repair the wiring harness.

STEP 13. Retest the system


Check that the front fog lamps illuminate normally.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

Replace the ETACS-ECU.