Part 1 of 2

Headlight, Taillight: Tail lights, the position lights, the rear side marker lights or the license plate light 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, the rear side marker lights 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 rear side marker light 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 Tools:
- MB991223: Harness Set

STEP 1. Verify the operation of each light.

Q: Which light does not illuminate?

taillight (LH), license plate light and rear side marker light (LH): Go to Step 2.
taillight (RH) and rear side marker light (RH): Go to Step 4.
position light: Go to Step 6.
position light (LH): Go to Step 9.
position light (RH): Go to Step 15.
taillight (LH): Go to Step 21.
taillight (RH): Go to Step 27.
license plate lights : Go to Step 33.
rear side marker light (LH): Go to Step 39.
rear side marker light (RH): Go to Step 45.
All lights : Refer to Inspection Procedure J-1 "Tail lights do not illuminate normally."

STEP 2. Check rear combination light (LH) connector D-18 and front-ECU connector A-11X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are rear combination light (LH) connector D-18 and front-ECU connector A-11X in good condition?

YES: Go to Step 3.

NO: Repair or replace the damaged components). Refer to Harness Connector Inspection. Verify that the taillight (LH), license plate light and rear side marker light (LH) illuminates normally.

STEP 3. Check the wiring harness between rear combination light (LH) connector D-18 (terminal 2) and front-ECU connector A-11X (terminal 4).

NOTE: Also check intermediate connectors C-116 and C-117 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-116 or C-117 is damaged, repair or replace the damaged components) as described in Harness Connector Inspection.

Q: Is the wiring harness between rear combination light (LH) connector D-18 (terminal 2) and front-ECU connector A-11X (terminal 4) 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), license plate light and rear side marker light (LH) illuminates normally.

STEP 4. Check rear combination light (RH) connector D-13 and front-ECU connector A-11X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are rear combination light (RH) connector D-13 and front-ECU connector A-11X in good condition?

YES: Go to Step 5.

NO: Repair or replace the damaged components). Refer to Harness Connector Inspection. Verify that the taillight (RH) and rear side marker light (RH) illuminates normally.

STEP 5. Check the wiring harness between rear combination light (RH) connector D-13 (terminal 2) and front-ECU connector A-11X (terminal 4).

NOTE: Also check intermediate connectors C-116, Disjunction block connectors C-202, C-209 and joint connector C-01 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-116, D-28, junction block connector C-202, C-209 or joint connector C-01 is damaged, repair or replace the damaged components) as described in Harness Connector Inspection.

Q: Is the wiring harness between rear combination light (LH) connector D-13 (terminal 2) and front-ECU connector A-11X (terminal 4) 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 (RH) and rear side marker light (RH) illuminates normally.

STEP 6. Check the ground circuit to the position light (LH). Measure the resistance at front combination light (LH) connector A-16.

1. Disconnect front combination light (LH) connector A-16 and measure the resistance available at the wiring harness side of the connector.

2. Measure the resistance value between terminal 3 and ground.
- The resistance should equal 2 Ohms or less.

Q: Is the measured resistance 2 Ohms or less?

YES: No action is necessary and testing is complete.

NO: Go to Step 7.

STEP 7. Check front combination light (LH) connector A-16 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front combination light (LH) connector A-16 in good condition?

YES: Go to Step 8.

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

STEP 8. Check the wiring harness between front combination light (LH) connector A-16 (terminal 3) and ground.

Q: Is the wiring harness between front combination light (LH) connector A-16 (terminal 3) 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 position light 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) illuminate normally.

STEP 10. Check front combination light (LH) connector A-16 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front combination light (LH) connector A-16 in good condition?

YES: Go to Step 11.

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

STEP 11. Check the ground circuit to the position light (LH). Measure the resistance at front combination light (LH) connector A-16.

1. Disconnect front combination light (LH) connector A-16 and measure the resistance available at the wiring harness side of the connector.

2. Measure the resistance value between terminal 3 and ground.
- The resistance should equal 2 Ohms or less.

Q: Is the measured resistance 2 Ohms or less?

YES: Go to Step 13.

NO: Go to Step 12.

STEP 12. Check the wiring harness between front combination light (LH) connector A-16 (terminal 3) and ground.

Q: Is the wiring harness between front combination light (LH) connector A-16 (terminal 3) and ground in good condition?

YES: Replace the position light socket (LH). Verify that the position light (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 position light (LH) illuminate normally.

STEP 13. Check front combination light (LH) connector A-16 and front-ECU connector A-11X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are front combination light (LH) connector A-16 and front-ECU connector A-11X 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 (LH) illuminate normally.

STEP 14. Check the wiring harness between front combination light (LH) connector A-16 (terminal 1) and front-ECU connector A-11X (terminal 4).

Q: Is the wiring harness between position light (LH) connector A-16 (terminal 1) and front-ECU connector A-11X (terminal 4) 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) illuminate normally.

STEP 15. 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 16.

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

STEP 16. Check front combination light (RH) connector A-28 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front combination light (RH) connector A-28 in good condition?

YES: Go to Step 17.

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

STEP 17. Check the ground circuit to the position light (RH). Measure the resistance at front combination light (RH) connector A-28.

1. Disconnect front combination light (RH) connector A-28 and measure the resistance available at the wiring harness side of the connector.

STEP 18. Check the wiring harness between front combination light (RH) connector A-28 (terminal 3) and ground.

Q: Is the wiring harness between front combination light (RH) connector A-28 (terminal 3) and ground in good condition?

YES: Replace the position light socket (RH). Verify that the position light (RH) 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 position light (RH) illuminate normally.

STEP 19. Check front combination light (RH) connector A-28 and front-ECU connector A-11X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are front combination light (RH) connector A-28 and front-ECU connector A-11X in good condition?

YES: Go to Step 20.

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

STEP 20. Check the wiring harness between front combination light (RH) connector A-28 (terminal 1) and front-ECU connector A-11X (terminal 4).

Q: Is the wiring harness between front combination light (RH) connector A-28 (terminal 1) and front-ECU connector A-11X (terminal 4) 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) illuminate normally.

STEP 21. 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 22.

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

STEP 22. Check rear combination light (LH) connector D-18 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is rear combination light (LH) connector D-18 in good condition?

YES: Go to Step 23.

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

STEP 23. Check the ground circuit to the taillight (LH). Measure the resistance at rear combination light (LH) connector D-18.

1. Disconnect rear combination light (LH) connector D-18 and measure the resistance available at the wiring harness side of the connector.

STEP 24. Check the wiring harness between rear combination light (LH) connector D-18 (terminal 3) and ground.

Q: Is the wiring harness between rear combination light (LH) connector D-18 (terminal 3) and ground in good condition?

YES: Replace the rear combination light socket (LH). Verify that the taillight (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 25. Check rear combination light (LH) connector D-18 and front-ECU connector A-11X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are rear combination light (LH) connector D-18 and front-ECU connector A-11X in good condition?

YES: Go to Step 26.

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