Inspection Procedure J-7

Headlight, Taillight: One of the headlights does not illuminate.

Headlight Circuit Part 1:

Headlight Circuit Part 2:

TECHNICAL DESCRIPTION (COMMENT)
If one of the headlights does not illuminate, a headlight bulb may be defective.

TROUBLESHOOTING HINTS
- The headlight 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 headlight operation.

Q: Which of the headlights does not illuminate?

No headlights illuminate : Go to Step 2.
LH (only low-beam): Go to Step 5.
RH (only low-beam): Go to Step 9.
LH (only high beam): Go to Step 13.
RH (only high beam): Go to Step 17.
Low beam only (both RH and LH): Refer to Inspection Procedure J-2 "Headlights (low-beam) do not illuminate normally."
High beam only (both RH and LH): Refer to Inspection Procedure J-3 "Headlights (high-beam) do not illuminate normally."
Only high-beam indicator light: Go to Step 21.




STEP 2. Check headlight (LOW: LH) connector A-15 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is headlight (LOW: LH) connector A-15 in good condition?

YES: Go to Step 3.

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

STEP 3. Check the ground circuit to the headlight (LOW: LH). Measure the resistance at headlight (LOW: LH) connector A-15.




1. Disconnect headlight (LH) connector A-15 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 4.




STEP 4. Check the wiring harness between headlight (LH) connector A-15 (terminal 3) and ground.

Q: Is the wiring harness between headlight (LH) connector A-15 (terminal 2) 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 headlights illuminate normally.




STEP 5. Check headlight (LOW: LH) connector A-15 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is headlight (LOW: LH) connector A-15 in good condition?

YES: Go to Step 6.

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

STEP 6. Check headlight (LOW: LH) bulb.

1. Remove the headlight (LOW: LH) bulb.
2. Verify that the headlight (LOW: LH) bulb is not damaged or burned out.

Q: Is headlight (LOW: LH) bulb normal?

YES: Go to Step 7.

NO: Replace the headlight (LOW: LH) bulb. Verify that the headlights illuminate normally.




STEP 7. Check front-ECU connector A-11X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front-ECU connector A-11X in good condition?

YES: Go to Step 8.

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







STEP 8. Check the wiring harness between headlight (LOW: LH) connector A-15 (terminal 2) and front-ECU connector A-11X (terminal 6).

Q: Is the wiring harness between headlight (LH) connector A-15 (terminal 1) and front-ECU connector A-11X (terminal 6) 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 headlights illuminate normally.




STEP 9. Check headlight (LOW: RH) connector A-29 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is headlight (LOW: RH) connector A-29 in good condition?

YES: Go to Step 10.

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

STEP 10. Check headlight (LOW: RH) bulb.

1. Remove the headlight (LOW: RH) bulb.
2. Verify that the headlight (LOW: RH) bulb is not damaged or burned out.

Q: Is headlight (LOW: RH) bulb normal?

YES: Go to Step 11.

NO: Replace the headlight (LOW: RH) bulb. Verify that the headlights illuminate normally.




STEP 11. Check front-ECU connector A-11X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front-ECU connector A-11X in good condition?

YES: Go to Step 12.

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







STEP 12. Check the wiring harness between headlight (LOW: RH) connector A-29 (terminal 2) and front-ECU connector A-11X (terminal 6).

Q: Is the wiring harness between headlight (RH) connector A-29 (terminal 2) and front-ECU connector A-11X (terminal 6) 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 headlights illuminate normally.




STEP 13. Check headlight (HIGH: LH) connector A-31 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: IS headlight (HIGH: LH) connector A-31 in good condition?

YES: Go to Step 14.

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

STEP 14. Check headlight (HIGH: LH) bulb.

1. Remove the headlight (HIGH: LH) bulb.
2. Verify that the headlight (HIGH: LH) bulb is not damaged or burned out.

Q: Is headlight (HIGH: LH) bulb normal?

YES: Go to Step 15.

NO: Replace the headlight (HIGH: LH) bulb. Verify that the headlights illuminate normally.




STEP 15. Check front-ECU connector A-11X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front-ECU connector A-11X in good condition?

YES: Go to Step 16.

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







STEP 16. Check the wiring harness between headlight (HIGH: LH) connector A-31 (terminal 1) and front-ECU connector A-11X (terminal 10).

Q: Is the wiring harness between headlight (LH) connector A-31 (terminal 1) and front-ECU connector A-11X (terminal 10) 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 headlights illuminate normally.




STEP 17. Check headlight (HIGH: RH) connector A-32 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is headlight (HIGH: RH) connector A-32 in good condition?

YES: Go to Step 18.

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

STEP 18. Check headlight (HIGH: RH) bulb.

1. Remove the headlight (HIGH: RH) bulb.
2. Verify that the headlight (HIGH: RH) bulb is not damaged or burned out.

Q: Is headlight (HIGH: RH) bulb normal?

YES: Go to Step 19.

NO: Replace the headlight (HIGH: RH) bulb. Verify that the headlights illuminate normally.




STEP 19. Check front-ECU connector A-11X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is 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 headlights illuminate normally.







STEP 20. Check the wiring harness between headlight (HIGH: RH) connector A-32 (terminal 1) and front-ECU connector A-11X (terminal 10).

Q: Is the wiring harness between headlight (HIGH: RH) connector A-32 (terminal 1) and front-ECU connector A-11X (terminal 10) 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 headlights illuminate normally.




STEP 21. Check combination meter connector C-05 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is combination meter connector C-05 in good condition?

YES: Go to Step 22.

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

STEP 22. Check high-beam indicator light bulb.

1. Remove the high-beam indicator light bulb.
2. Verify that the high-beam indicator light bulb is not damaged or burned out.

Q: Is the high-beam indicator light normal?

YES: Go to Step 23.

NO: Replace the bulb. Verify that the high-beam indicator light illuminates normally.




STEP 23. Check front-ECU connector A-11X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front-ECU connector A-11X in good condition?

YES: Go to Step 24.

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







STEP 24. Check the wiring harness between combination meter connector C-05 (terminal 9) and front-ECU connector A-11X (terminal 10).






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

Q: Is the wiring harness between combination meter connector C-05 (terminal 9) and front-ECU connector A-11X (terminal 1) 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 high-beam indicator light illuminates normally.