Honda Odyssey Service Manual: Exterior Lighting

Headlights   System Description

The headlight system is composed of the MICU, the relay control module, the taillight relay, the headlight and dimmer/flash-to-pass switches (inside the combination light switch), the headlights, and the high beam indicator.

The taillight relay controls each side of the front parking/side marker light, taillights, rear side marker light, and license plate lights. The headlights, daytime running lights, and the turn signal/hazard lights are controlled by the MICU. The back-up lights are controlled by the reverse relay.

Low Beams

When you move the headlight switch to the headlight ON position and the dimmer/flash-to-pass switch to the low position, a ground signal is supplied to terminal No. 15 of driver's under-dash fuse/relay box connector P (24P). The MICU then energizes the low beams control circuit, supplying battery voltage to the low beams of the left headlights, turning them on.

NOTE: If there is a B-CAN communication failure, the headlight back-up circuit commands the right low beam to come on when the ignition is on and the headlight switch is in the ON position. The right high beam does not come on if there is a B-CAN system failure.

High Beams

When you move the headlight switch to the headlight ON position and the dimmer/flash-to-pass switch to the high position, ground signals are supplied to terminals No. 19 and No. 21 of driver's under-dash fuse/relay box (MICU) connector P (24P). The MICU then energizes each side of the high beam headlight control circuits, supplying battery voltage to the high beam headlights, turning them on.

Flash-to-Pass

When you pull the dimmer/flash-to-pass switch to the passing position, a ground signal is supplied to terminal No. 20 of the driver's under-dash fuse/relay box (MICU) connector P (24P). The MICU then energizes the high beam control circuits for as long as the switch is held, supplying battery voltage to the high beam headlights, turning them on.