Step 1. Check that the tail lamps and headlamps operate.

Check that the tail lamps and headlamps illuminate normally.

Q: Is the check result normal?

YES:  Go to Step 2.
NO:  Repair the tail lamp(s) and headlamp(s). Refer to trouble symptom chart .

Step 2. ECU check by using the SWS monitor

Check that the power supply and earth lines to the column switch (column-ECU), the ETACS-ECU and the front-ECU and the SWS communication lines are normal.

• Ignition switch: OFF

ECUS TO BE CHECKED

• COLUMN ECU

• ETACS ECU

• FRONT ECU

OK: "OK" are displayed for all the items

Q: Is the check result normal?

"OK" are displayed for all the items:  Go to Step 3.
"NG" is displayed on the "COLUMN ECU" menu.:  Refer to Inspection Procedure A-2 "Communication with column switch (column-ECU) is not possible ."
"NG" is displayed on the "ETACS ECU" menu.:  Refer to Inspection Procedure A-3 "Communication with ETACS-ECU is not possible ."
"NG" is displayed on the "FRONT ECU" menu.:  Refer to Inspection Procedure A-4 "Communication with front-ECU is not possible ."

Step 3. Function diagnosis by using the SWS monitor

Check the SWS communication signal, which are related to the fog lamps.

<Selected item> LIGHTING - F.FOG LAMP

• Ignition switch: ON

• Lighting switch: "TAIL" or "HEAD"

• Front fog lamp switch: ON

Item No.	Item name	Normal condition
Item 00	HEADLAMP SW	ON when the lighting switch is at HEAD
Item 01	TAIL LAMP SW	ON when the lighting switch is at TAIL or HEAD
Item 30	IG SW(IG1)*	ON
Item 36	F.FOG LAMP	ON
Item 70	FRONT ECU ACK	NORMAL ACK or HI-BEAM ACK

NOTE: ^* : Except for Australia

OK: Normal conditions are displayed for all the items.

Q: Is the check result normal?

Normal conditions are displayed for all the items.:  Go to Step 4.
Normal condition is not displayed for item 00 or 01.:  Refer to Inspection Procedure P-5 "The column switch (lighting and turn-signal lamp switch) signal is not received ."
Normal condition is not displayed for item No.30.:  Refer to Inspection Procedure P-2 "The ignition switch (IG1) signal is not received ."
Normal condition is not displayed for item No.36.:  Refer to Inspection Procedure P-10 "The front fog lamp switch signal is not received ."
Normal condition is not displayed for item No.70.:  Replace the front-ECU.

Step 4. Connector check: A-05X fog lamp relay connector

Q: Is the check result normal?

YES:  Go to Step 5.
NO:  Repair the defective connector.

Step 5. Check the fog lamp relay.

Refer to GROUP 54A - Fogl lamp .
YES:  Go to Step 6.
NO:  Replace the fog lamp relay.

Step 6. Measure the voltage at the A-05X fog lamp relay connector.

1. Remove the fog lamp relay, and measure at the relay box side.

2. Check the voltage between the fog lamp relay connector and body earth.
• Voltage between A-05X fog lamp relay connector terminal No.1 and body earth
• Voltage between A-05X fog lamp relay connector terminal No.2 and body earth
OK: Battery positive voltage

Q: Is the check result normal?

YES:  Go to Step 8.
NO:  Go to Step 7.

Step 7. Check the wiring harness between A-05X fog lamp relay connector (terminal Nos.1 and 2) and the battery.

• Check the power supply line for open circuit.

Q: Is the check result normal?

YES:  The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
NO:  Repair the wiring harness.

Step 8. Connector check: A-11X front-ECU connector

Q: Is the check result normal?

YES:  Go to Step 9.
NO:  Repair the defective connector.

Step 9. Check the wiring harness between A-05X fog lamp relay connector terminal No.3 and A-11X front-ECU connector terminal No.11.

• Check the output lines for open circuit.

Q: Is the check result normal?

YES:  Go to Step 10.
NO:  Repair the wiring harness.

Step 10. Retest the system.

Check that the fog lamps illuminate normally.

Q: Is the check result normal?

YES:  The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
NO:  Replace the ETACS-ECU.