Test No. 6: Low Beam Headlight Does Not Operate

CAUTION: When handling halogen headlight bulb, DO NOT scratch or drop the headlight bulb, as headlight bulb is pressurized and may bust. DO NOT touch glass part of headlight bulb with your hands. Hold headlight bulb only by the plastic or metal case.

Remove and examine headlight bulb which is not operating. If headlight bulb is okay, go to next step. If headlight bulb is defective, replace headlight bulb and recheck headlight operation.
On models without daytime running lights, go to next step. On models with daytime running lights, depending on which headlight is inoperative, check HEAD LH LWR fuse (15-amp) for driver's side headlight or HEAD RH LWR fuse (15-amp) for passenger's side headlight. These fuses are located in fuse/relay box as driver's side front corner of engine compartment. See Figure. If fuse is okay, go to next step. If fuse is defective, repair short in wiring between appropriate fuse and headlight. See WIRING DIAGRAMS in DAYTIME RUNNING LIGHTS article.
On all models, check headlight relay. See HEADLIGHT RELAY under COMPONENT TESTS. If headlight relay is okay, go to next step. If headlight relay is defective, replace headlight relay and recheck headlight operation.
Check wiring harness and electrical connectors between battery and headlight relay, and between headlight relay and Body Electronic Control Unit (ECU). See WIRING DIAGRAMS in HEADLIGHT SYSTEMS or DAYTIME RUNNING LIGHTS article. Body ECU is located at driver's side of instrument panel on the fuse/relay box. See Figure. Electrical connector B4 (25-pin) and electrical connector B5 (25-pin) are located at each side of body ECU and a 12-pin electrical connector at rear of body ECU. See Figure. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary and recheck headlight operation.
Check headlight control switch. See HEADLIGHT CONTROL SWITCH under COMPONENT TESTS. If headlight control switch is okay, go to next step. If headlight control switch is defective, replace headlight control switch and recheck headlight operation. See HEADLIGHT CONTROL SWITCH under REMOVAL & INSTALLATION.
Check wiring harness and electrical connectors between headlight control switch and body ECU, between body ECU and headlight relay, and between headlight relay, headlights and ground connections. See WIRING DIAGRAMS in HEADLIGHT SYSTEMS or DAYTIME RUNNING LIGHTS article. On all models, repair wiring harness or electrical connector as necessary and recheck headlight operation.