Inspection Procedure 5

Inspection Procedure 5: One Of The Headlights Does Not Illuminate.

Headlight Circuit [Halogen Types]:

Headlight Circuit [Discharge Types] (Part 1):

Headlight Circuit [Discharge Types] (Part 2):

TROUBLESHOOTING HINTS
- Malfunction of the headlight bulbs
- Malfunction of the headlight assembly
- Damaged harness wires and connectors

TECHNICAL DESCRIPTION (COMMENT)
If one of the headlights does not Illuminate, the wiring harness, connector(s), or the bulb may have a problem, or the fuse may be burned out.

DIAGNOSIS

Required Special Tools:
- MB992006: Extra fine probe
- MB991223: Harness set

STEP 1. Check headlight assembly connector A-40 [LH] or A-57 [RH], for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is headlight assembly connector A-40 [LH] or A-57 [RH] in good condition?

YES : Go to Step 2.

NO : Repair or replace the damaged component(s).

STEP 2. Check bulb.

Check the bulb(s) of headlight that does not illuminate.

NOTE: If discharge-type lower beam headlights do not illuminate, their bulbs cannot be inspected. In this case, assume the bulbs to be normal and proceed with steps.

Q: Is the bulb in good condition?

YES : Go to Step 3.

NO : Replace the bulb(s) of the light that does not illuminate.

STEP 3. Check the wiring harness between headlight assembly connector and headlight relay connector or wiring harness between headlight assembly connector and ground.

Check the power supply or ground line for open circuit.

[Halogen type headlight]
- Check the wiring harness between headlight assembly (LH) connector A-40 (terminal 2) and headlight relay (LOW) connector A-29X (terminal 3). [LH-LOW]
- Check the wiring harness between headlight assembly (LH) connector A-40 (terminal 1) and headlight relay (HIGH) connector A-21X (terminal 3). [LH-HIGH]
- Check the wiring harness between headlight assembly (LH) connector A-40 (terminal 6) and ground. [LH-LOW and HIGH]
- Check the wiring harness between headlight assembly (RH) connector A-57 (terminal 2) and headlight relay (LOW) connector A-29X (terminal 3). [RH-LOW]
- Check the wiring harness between headlight assembly (RH) connector A-57 (terminal 1) and headlight relay (HIGH) connector A-21X (terminal 3). [RH-HIGH]
- Check the wiring harness between headlight assembly (RH) connector A-57 (terminal 6) and ground. [RH-LOW and HIGH]

[Discharge type headlight]
- Check the wiring harness between headlight assembly (LH) connector A-40 (terminal 12) and headlight relay (LOW) connector A-29X (terminal 3). [LH-LOW]
- Check the wiring harness between headlight assembly (LH) connector A-40 (terminal 1) and headlight relay (HIGH) connector A-21X (terminal 3). [LH-HIGH]
- Check the wiring harness between headlight assembly (LH) connector A-40 (terminal 5) and ground. [LH-LOW and HIGH]
- Check the wiring harness between headlight assembly (RH) connector A-57 (terminal 12) and headlight relay (LOW) connector A-29X (terminal 3). [RH-LOW]
- Check the wiring harness between headlight assembly (RH) connector A-57 (terminal 1) and headlight relay (HIGH) connector A-21X (terminal 3). [RH-HIGH]
- Check the wiring harness between headlight assembly (RH) connector A-57 (terminal 5) and ground. [RH-LOW and HIGH]

Q: Is the wiring harness between headlight assembly connector and headlight relay connector in good condition?

YES : Replace the headlight assembly that does not illuminate.

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.