Part 1

Headlight and Taillight: Any of taillights, the position lights or the license plate lights do not illuminate.

Taillights, Position Lights, Side Marker Lights And License Plate Lights Circuit Part 1:

Taillights, Position Lights, Side Marker Lights And License Plate Lights Circuit Part 2:

TECHNICAL DESCRIPTION (COMMENT)
If the position lights, the taillights or the license plate lights do not illuminate, their bulb may be defective.

TROUBLESHOOTING HINTS
- The position light bulb may be defective
- The stop/taillight bulb may be defective
- The license plate light bulb may be defective
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tool:
- MB991223: Harness Set

STEP 1. Verify the operation of each light.

Q: Which light does not illuminate?

The position light (LH), the taillight (LH), the license plate lights and the side marker lights: Go to Step 2.

The taillight (LH), the license plate lights and the side marker lights: Go to Step 3.

The position light (RH) and the taillights (RH): Go to Step 4.

The license plate lights and the side marker lights: Go to Step 5.

The position light (LH): Go to Step 8

The position light (RH): Go to Step 14

The taillight (LH): Go to Step 20.

The taillight (RH): Go to Step 23.

The license plate light (LH): Go to Step 28.

The license plate light (RH): Go to Step 33.

The side marker light (LH): Go to Step 38.

The side marker light (RH): Go to Step 43.

All lights: Refer to Inspection Procedure J-1 "Taillights do not illuminate."

STEP 2. Check the wiring harness between front combination light assembly (LH) connector A-31 (terminal 3) and front-ECU connector A-10X (terminal 8).

Q: Is the wiring harness between front combination light assembly (LH) connector A-31 (terminal 3) and front-ECU connector A-10X (terminal 8) in good condition?

YES: No action is necessary and testing is complete.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the taillight (LH), the position light (LH), the license plate lights and the side marker lights should illuminate normally.

STEP 3. Check the wiring harness between front-ECU connector A-10X (terminal 8) and rear combination light assembly (LH) connector F-14 (terminal 3).

NOTE: Also check junction block connectors C-210, C-217 and intermediate connector C-129 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If junction block connector C-210, C-217 or intermediate connector C-129 is damaged, repair or replace the damaged components) as described in Harness Connector Inspection.

Q: Is the wiring harness between front-ECU connector A-10X (terminal 8) and rear combination light assembly (LH) connector F-14 (terminal 3) in good condition?

YES: No action is necessary and testing is complete.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the taillight (LH), the license plate lights and the side marker lights should illuminate normally.

STEP 4. Check the wiring harness between front combination light assembly (RH) connector A-39 (terminal 3) and front-ECU connector A-10X (terminal 8).

Q: Is the wiring harness between front combination light assembly (RH) connector A-39 (terminal 3) and front-ECU connector A-10X (terminal 8) in good condition?

YES: No action is necessary and testing is complete.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the position light (RH) and the taillight (RH) illuminate normally.

STEP 5. Check the ground circuit to the license plate light (LH). Measure the resistance at side marker light (LH) connector F-20.

1. Disconnect side marker light (LH) connector F-20 and measure the resistance available at the wiring harness side of the connector.

2. Measure the resistance value between terminal 1 and ground.
- The resistance should equal 2 ohms or less.

Q: Is the measured resistance 2 ohms or less?

YES: Go to Step 7.

NO: Go to Step 6.

STEP 6. Check the wiring harness between side marker light (LH) connector F-20 (terminal 1) and ground.

NOTE: Also check intermediate connector F-12 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector F-12 is damaged, repair or replace the damaged components) as described in Harness Connector Inspection.

Q: Is the wiring harness between side marker light (LH) connector F-20 (terminal 1) and ground in good condition?

YES: No action is necessary and testing is complete.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the license plate lights and side marker lights illuminates normally.

STEP 7. Check the wiring harness between license plate light (LH) connector F-11 (terminal 2) and junction block connector C-217 (terminal 2).

NOTE: Also check intermediate connector F-12 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector F-12 is damaged, repair or replace the damaged components) as described in Harness Connector Inspection.

Q: Is the wiring harness between license plate light (LH) connector F-11 (terminal 2) and junction block connector C-217 (terminal 2) in good condition?

YES: No action is necessary and testing is complete.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the license plate lights and side marker lights illuminate normally.

STEP 8. Check front combination light assembly (LH) connector A-31 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front combination light assembly (LH) connector A-31 in good condition?

YES: Go to Step 9.

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Verify that the position light (LH) illuminates normally.

STEP 9. Check the position light bulb (LH).
1. Remove the position light bulb (LH).
2. Verify that the position light bulb (LH) is not damaged or burned out.

Q: Is the position light bulb (LH) in good condition?

YES: Go to Step 10.

NO: Replace the position light bulb (LH). Verify that the position light (LH) illuminates normally.

STEP 10. Check the ground circuit to the position light (LH). Measure the resistance at front combination light assembly (LH) connector A-31.

1. Disconnect front combination light assembly (LH) connector A-31 and measure the resistance available at the wiring harness side of the connector.

2. Measure the resistance value between terminal 7 and ground.
- The resistance should equal 2 ohms or less.

Q: Is the measured resistance 2 ohms or less?

YES: Go to Step 12.

NO: Go to Step 11.

STEP 11. Check the wiring harness between front combination light assembly (LH) connector A-31 (terminal 7) and ground.

Q: Is the wiring harness between position light (LH) connector A-31 (terminal 7) and ground in good condition?

YES: Replace the front combination light assembly (LH). Verify that the position light (LH) illuminates normally.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the position light (LH) illuminates normally.

STEP 12. Check the wiring harness between front combination light assembly (LH) connector A-31 (terminal 3) and front-ECU connector A-10X (terminal 8).

Q: Is the wiring harness between front combination light assembly (LH) connector A-31 (terminal 3) and front-ECU connector A-10X (terminal 8) in good condition?

YES: Replace the front combination light assembly (LH). Verify that the position light (LH) illuminates normally.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the position light (LH) illuminates normally.

STEP 13. Check front combination light assembly (RH) connector A-39 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front combination light assembly (RH) connector A-39 in good condition?

YES: Go to Step 14.

NO: Repair or replace the damaged components). Refer to Harness Connector Inspection. Verify that the position light (RH) illuminates normally.

STEP 14. Check the position light bulb (RH).
1. Remove the position light bulb (RH).
2. Verify that the position light bulb (RH) is not damaged or burned out.

Q: Is the position light bulb (RH) in good condition?

YES: Go to Step 15.

NO: Replace the position light bulb (RH). Verify that the position light (RH) illuminates normally.

STEP 15. Check the ground circuit to the position light (LH). Measure the resistance at front combination light assembly (LH) connector A-39.

1. Disconnect front combination light assembly (LH) connector A-39 and measure the resistance available at the wiring harness side of the connector.

2. Measure the resistance value between terminal 7 and ground.
- The resistance should equal 2 ohms or less.

Q: Is the measured resistance 2 ohms or less?

YES: Go to Step 17.

NO: Go to Step 16.

STEP 16. Check the wiring harness between front combination light assembly (RH) connector A-39 (terminal 7) and ground.

Q: Is the wiring harness between front combination light assembly (RH) connector A-39 (terminal 1) and ground in good condition?

YES: Replace the front combination light assembly (RH). Verify that the position light (RH) illuminates normally.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the position light (RH) illuminates normally.

STEP 17. Check the wiring harness between front combination light assembly (RH) connector A-39 (terminal 3) and front-ECU connector A-10X (terminal 8).

Q: Is the wiring harness between front combination light assembly (RH) connector A-39 (terminal 1) and front-ECU connector A-10X (terminal 8) in good condition?

YES: Replace the front combination light assembly (RH). Verify that the position light (RH) illuminates normally.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the position light (RH) illuminates normally.

STEP 18. Check rear combination light assembly (LH) connector F-14 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is rear combination light assembly (LH) connector F-14 in good condition?

YES: Go to Step 19.

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Verify that the taillights (LH) illuminate normally.

STEP 19. Check the stop/taillight bulb (LH).
1. Remove the stop/taillight bulb (LH).
2. Verify that the stop/taillight bulb (LH) is not damaged or burned out.

Q: Is the stop/taillight bulb (LH) in good condition?

YES: Go to Step 20.

NO: Replace the stop/taillight bulb (LH). Verify that the taillights (LH) illuminate normally.

STEP 20. Check the ground circuit to the rear combination light (LH). Measure the resistance at rear combination light assembly (LH) connector F-14.

1. Disconnect rear combination light assembly (LH) connector F-14 and measure the resistance available at the wiring harness side of the connector.

2. Measure the resistance value between terminal 5 and ground.
- The resistance should equal 2 ohms or less.

Q: Is the measured resistance 2 ohms or less?

YES: Go to Step 22.

NO: Go to Step 21.

STEP 21. Check the wiring harness between rear combination light assembly (LH) connector F-14 (terminal 5) and ground.

Q: Is the wiring harness between rear combination light assembly (LH) connector F-14 (terminal 5) and ground in good condition?

YES: Replace the rear combination light assembly (LH). Verify that the taillight (LH) illuminates normally.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the taillights (LH) illuminate normally.

STEP 22. Check the wiring harness between rear combination light assembly (LH) connector F-14 (terminal 3) and junction block connector C-217 (terminal 2).

Q: Is the wiring harness between rear combination light assembly (LH) connector F-14 (terminal 3) and junction block connector C-217 (terminal 2) in good condition?

YES: Replace the rear combination light assembly (LH). Verify that the taillights (LH) illuminate normally.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the taillights (LH) illuminate normally.

STEP 23. Check rear combination light assembly (RH) connector F-08 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is rear combination light assembly (RH) connector F-08 in good condition?

YES: Go to Step 24.

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Verify that the taillight (RH) illuminates normally.

STEP 24. Check the stop/taillight bulb (RH).
1. Remove the stop/taillight bulb (RH).
2. Verify that the stop/taillight bulb (RH) is not damaged or burned out.

Q: Is the stop/taillight bulb (RH) in good condition?

YES: Go to Step 25.

NO: Replace the stop/taillight bulb (RH). Verify that the taillight (RH) illuminates normally.

STEP 25. Check the ground circuit to the rear combination light (RH). Measure the resistance at rear combination light assembly (RH) connector F-08.

1. Disconnect rear combination light assembly (RH) connector F-08 and measure the resistance available at the wiring harness side of the connector.