Headlights (USA)

Exterior Lights

How the Headlights - USA - Circuit Works

Low Beam

The headlight relays receive battery voltage at all times from the driver's multiplex control unit. When you turn the headlight switch to the HEAD position with the dimmer switch in LOW, ground is applied through the GRN wire to the coils of the headlight relays. The relays are then energized, applying battery voltage to the left and right high and low beam headlight filaments through fuses 43 and 45. The low beam filaments come on because they are grounded. The high beams and indicator remain off because the dimmer switch and flash-to-pass switch interrupts their ground path.

High Beams

The headlight relays receive battery voltage at all times from the driver's multiplex control unit. When you turn the headlight switch to the HEAD position with the dimmer switch in HIGH, ground is applied through the GRN wire to the coils of the headlight relays. The relays are then energized, applying battery voltage to the left and right high and low beam headlights filaments through fuses 43 and 45. The high beam filaments and indicator come on because they are grounded through the dimmer switch.

Flash-to-Pass

When you hold the flash-to-pass switch in the ON position, ground is applied through the GRN wire to the coils of the headlight relays. The relays are then energized, applying battery voltage to the left and right high and low beam headlights filaments through fuses 43 and 45. The high beams and indicator come on because a path to ground is provided through the closed flash-to-pass switch.

Auto-off Lights Function (EX, EX-L)

The headlight relays are controlled by the driver's multiplex control unit. If you leave the headlight switch in the HEAD position and exit the vehicle, the control unit will automatically turn the exterior lights off within 15 seconds after you close the doors. When you unlock or open the driver's door, the control unit automatically turns the lights back on.