Part 1 of 2

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

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

Taillights, Position 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

STEP1. Verify the operation of each light.

Q: Which light does not illuminate?

taillights (LH) and license plate light : Go to Step 2.

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

position light (LH) : Go to Step 6.

position light (RH) : Go to Step 12.

taillight (LH) : Go to Step 18.

taillight (RH) : Go to Step 24.

license plate lights : Go to Step 30.

license plate light (LH) : Go to Step 35.

license plate light (RH) : Go to Step 41.

position light (LH), taillight (LH) and license plate light : Go to Step 47.

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

STEP 2. Check rear combination light assembly (LH) connector F-14 and front-ECU connector A-10X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are rear combination light assembly (LH) connector F-14 and front-ECU connector A-10X in good condition?

YES: Go to step 3

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. The taillight (LH) and the license plate lights should illuminate normally.

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

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 connectors C-210, C-217 or intermediate connector C-129 is damaged, repair or replace the damaged component(s) as described in Harness Connector Inspection.

Q: Is the wiring harness between rear combination light assembly (LH) connector F-14 (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. The taillight (LH) and the license plate lights should illuminate normally.

STEP 4. Check rear combination light assembly (RH) connector F-08 and front-ECU connector A-10X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are rear combination light assembly (RH) connector F-08 and front-ECU connector A-10X in good condition?

YES: Go to Step 5.

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. The position light (RH) and the taillight (RH) should illuminate normally.

STEP 5. Check the wiring harness between rear combination light assembly (RH) connector F-08 (terminal 3) and front-ECU connector A-10X (terminal 8).

NOTE: Also check joint connector C-05, intermediate connectors C-111 and C-129 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector C-05, intermediate connectors C-111 or C-129 is damaged, repair or replace the damaged component(s) as described in Harness Connector Inspection.

Q: Is the wiring harness between position light (RH) connector F-08 (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. The position light (RH) and the taillight (RH) should illuminate normally.

STEP 6. Check position light (LH) connector A-14 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is position light (LH) connector A-14 in good condition?

YES: Go to Step 7.

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

STEP 7. 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 8.

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

STEP 8. Check the ground circuit to the position light (LH). Test at position light (LH) connector A-14.

1. Disconnect position light (LH) connector A-14 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 10.

NO: Go to Step 9.

STEP 9. Check the wiring harness between position light (LH) connector A-14 (terminal 1) and ground.

Q: Is the wiring harness between position light (LH) connector A-14 (terminal 1) and ground in good condition?

YES: Replace the position light socket (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 10. Check front-ECU connector A-10X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front-ECU connector A-10X in good condition?

YES: Go to Step 11.

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

STEP 11. Check the wiring harness between position light (LH) connector A-14 (terminal 2) and front-ECU connector A-10X (terminal 8).

Q: Is the wiring harness between position light (LH) connector A-14 (terminal 2) 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 (LH) illuminates normally.

STEP 12. Check position light (RH) connector A-24 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is position light (RH) connector A-24 in good condition?

YES: Go to Step 13.

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

STEP 13. 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 14.

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

STEP 14. Check the ground circuit to the position light (LH). Test at position light (LH) connector A-24.

1. Disconnect position light (LH) connector A-24 and measure the resistance available at the wiring harness side of the connector.

STEP 15. Check the wiring harness between position light (RH) connector A-24 (terminal 1) and ground.

Q: Is the wiring harness between position light (RH) connector A-24 (terminal 1) and ground in good condition?

YES: Replace the position light socket (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 16. Check front-ECU connector A-10X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front-ECU connector A-10X in good condition?

YES: Go to Step 17.

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

STEP 17. Check the wiring harness between position light (RH) connector A-24 (terminal 2) and front-ECU connector A-10X (terminal 8).

Q: Is the wiring harness between position light (RH) connector A-24 (terminal 2) 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) illuminates normally.

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

Q: Is rear combination light (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). Test at rear combination light (LH) connector F-14.

1. Disconnect rear combination light (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 (LH) connector F-14 (terminal 5) and ground.

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

YES: Replace the rear combination light socket (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 front-ECU connector A-10X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front-ECU connector A-10X in good condition?

YES: Go to Step 23.

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

STEP 23. Check the wiring harness between rear combination light (LH) connector F-14 (terminal 3) and front-ECU connector A-10X (terminal 8).

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

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

YES: Replace the rear combination light socket (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 24. Check rear combination light (RH) connector F-08 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

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

YES: Go to Step 25.

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

STEP 25. 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 26.

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