Inspection Procedure 5: One of the headlight(s) does not illuminate: Diagnosis

WARNING: This page is about a different car, the 2015 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

Required Special Tools:

MB992006: Extra fine probe
MB991223: Harness set

STEP 1. Check headlight assembly connector A-31 < LH > or A-47 < RH >, for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is headlight assembly connector A-31 < LH > or A-47 < RH > in good condition?
1. YES: Go to Step 2.
2. NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
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?
1. YES: Go to Step 3.
2. 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.
Check the power supply line for open circuit.
- Check the wiring harness between headlight assembly (LH) connector A-31 (terminal 2) and headlight relay (LOW) connector A-25X (terminal 3). < LH-LOW >
- Check the wiring harness between headlight assembly (LH) connector A-31 (terminal 1) and headlight relay (HIGH) connector A-17X (terminal 3). < LH-HIGH >
- Check the wiring harness between headlight assembly (LH) connector A-31 (terminal 6) and ground. < LH-LOW and HIGH >
- Check the wiring harness between headlight assembly (RH) connector A-47 (terminal 2) and headlight relay (LOW) connector A-25X (terminal 3). < RH-LOW >
- Check the wiring harness between headlight assembly (RH) connector A-47 (terminal 1) and headlight relay (HIGH) connector A-17X (terminal 3). < RH-HIGH >
- Check the wiring harness between headlight assembly (RH) connector A-47 (terminal 6) and ground. < RH-LOW and HIGH >
Q: Is the wiring harness between headlight assembly connector and headlight relay connector in good condition?
1. YES: Replace the headlight assembly that does not illuminate.
2. 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.