Inspection Procedure 3: The Rear Fog Lamp do not Illuminate Normally.

caution

Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.

PROBABLE CAUSES

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

DIAGNOSIS PROCEDURE

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?

Go to Step 2.

Check the tail lamps and the headlamps (Refer to trouble symptom chart

<tail lamp>,

<headlamp>).

STEP 2. ECU check by using the SWS monitor

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

Ignition switch: OFF

ECUS TO BE CHECKED

COLUMN ECU
ETACS ECU

OK: "OK" is displayed for all the items

Q. Is the check result normal?

YES ("OK" is displayed for all the items)

: Go to Step 3.

NO ("NG" is displayed on the "COLUMN ECU" menu) : Refer to GROUP 54C - Trouble Symptom Chart

.

NO ("NG" is displayed on the "ETACS ECU" menu) : Refer to GROUP 54C - Trouble Symptom Chart

STEP 3. Function diagnosis by using the SWS monitor

Check the SWS communication signal, which are related to the fog lamps.
<Selected item> LIGHTING - REAR FOG LAMP

Ignition switch: ON
Lighting switch: "TAIL" or "HEAD"
Rear 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

OK: Normal conditions are displayed for all the items.

Q. Is the check result normal?

YES (Normal conditions are displayed for all the items)

: Go to Step 4.

NO (Normal condition is not displayed for item 00 or 01) : Refer to ETACS - Input Signal Chart

STEP 4. ETACS switch data by using the SWS monitor

Check the input signals below, which are related to the rear fog lamp.

Rear fog lamp switch: from OFF to ON

Item No.	Item name	Normal conditions
Item 11	Rear fog lamp switch	OFF to ON (only when switch is operated)

OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 5.

Refer to ETACS - Input Signal Chart

STEP 5. Connector check: G-09 rear fog lamp connector

Q. Is the check result normal?

Go to Step 6.

Repair the defective connector.

STEP 6. Check the bulbs of the rear fog lamp.

Check the bulb(s) of the defective lamp.

Q. Is the check result normal?

Go to Step 7.

Replace the bulb(s) of the defective lamp.

STEP 7. Resistance measurement at the G-09 rear fog lamp connector.

(1)Disconnect the connector, and measure at the wiring harness side.

(2)Check the resistance between the lamp connector and body earth.

Resistance between G-09 rear fog lamp connector terminal No.1 and body earth

OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 9.

Go to Step 8.

STEP 8. Check the wiring harness from G-09 rear fog lamp connector terminal No.1 to body earth.

Check the earth wires for open circuit.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction

Repair the wiring harness.

STEP 9. Connector check: D-414 rear fog lamp relay connector

Q. Is the check result normal?

Go to Step 10.

Repair the defective connector.

STEP 10. Check the rear fog lamp relay.

Refer to rear fog lamp relay check

Q. Is the check result normal?

Go to Step 11.

Replace the rear fog lamp relay.

STEP 11. Voltage measurement at the D-414 rear fog lamp relay connector.

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

(2)Check the voltage between the rear fog lamp relay connector and body earth.

Voltage between D-414 rear fog lamp relay connector terminal No.3 and body earth
Voltage between D-414 rear fog lamp relay connector terminal No.4 and body earth

OK: System voltage

Q. Is the check result normal?

Go to Step 13.

Go to Step 12.

STEP 12. Check the wiring harness between D-414 rear fog lamp relay connector (terminal Nos.3 and 4) and the Fusible link (2).

note

Prior to the wiring harness inspection, check intermediate connector D-240 and junction block connectors D-402, D-404 and D-405, and repair if necessary.

Check the power supply line for open circuit.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction

Repair the wiring harness.

STEP 13. Check the wiring harness from G-09 rear fog lamp connector terminal No.2 to D-414 rear fog lamp relay connector terminal No.1.

note

Prior to the wiring harness inspection, check intermediate connector D-222, E-106 and junction block connector D-402, and repair if necessary.

Check the output lines for open circuit.

Q. Is the check result normal?

Go to Step 14.

Repair the wiring harness.

STEP 14. Connector check: D-420 ETACS-ECU connector

Q. Is the check result normal?

Go to Step 15.

Repair the defective connector.

STEP 15. Check the wiring harness between D-414 rear fog lamp relay connector terminal No.2 and D-420 ETACS-ECU connector terminal No.74.

note

Prior to the wiring harness inspection, check junction block connector D-402, and repair if necessary.

Check the output lines for open circuit.

Q. Is the check result normal?

Go to Step 16.

Repair the wiring harness.

STEP 16. Retest the system.

Check that the rear fog lamps illuminate normally.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction

Replace the ETACS-ECU.