Lighting and Horns: Description and Operation
Exterior Lights System Description
Headlights System Description
The headlight system is composed of the driver's MICU, the passenger's MICU, the headlight and dimmer/flash-to-pass switches (inside the combination light switch), the left and right headlights, and the high beam indicator.
Each MICU controls each side of the front parking/side marker light, daytime running light, headlights, taillights, rear side marker light, and license plate lights. The back-up lights and the turn signal/hazard lights are controlled by the driver's MICU.
Low Beams
When you move the headlight switch to the ON position and the dimmer/flash-to-pass switch to the low position, a ground signal is supplied to terminal No. 8 of driver's under-dash fuse/relay box connector R (24P). The driver's MICU then energizes the low beam control circuit, supplying battery voltage to the low beam of the left headlight, turning it on. Also the driver's MICU sends the message to the passenger's MICU via the B-CAN communication lines. The passenger's MICU then energizes the low beam control circuit, supplying battery voltage to the low beam of the right headlight, turning it 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 turn the headlight switch to the ON position and the dimmer/flash-to-pass switch to the high position, ground signals are supplied to terminals No. 8 and No. 22 of driver's under-dash fuse/relay box (driver's MICU) connector R (24P). The driver's and passenger's MICUs then energize the 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. 21 of driver's under-dash fuse/relay box (MICU) connector R (24P). The driver's and passenger's MICUs then energize the high beam control circuits for as long as the switch is held, supplying battery voltage to the high beam headlights, turning them on.
Daytime Running Lights System Description
The daytime running lights system includes the driver's and passenger's MICUs, the left and right daytime running lights (built into the headlights), the parking brake switch, and the DRL indication on the multi-information display (MID). The daytime running lights operate with the ignition switch turned to ON (II), or the engine start/stop button is pressed to select the ON mode, the headlights off (headlight switch OFF or in the parking position), and the parking brake released.
When the daytime running lights are on, the driver's and passenger's MICUs turn each relative daytime running light control circuit on and off (duty cycle), which provides a reduced voltage (approximately 6-8 volts) to the daytime running light (via the No. 28 fuse in the driver's under-dash fuse/relay box and No. 1 fuse in the passenger's under-dash fuse/relay box); the daytime running light come on with reduced brightness. The MICUs also send signals to the gauge control module, and the DRL indication is indicated by the lights-on indicator.
NOTE:
- The daytime running lights are disabled when the ignition switch is turned to LOCK (0), or the engine start/stop button is pressed to select the OFF mode. To keep the daytime running lights from coming on, apply the parking brake switch while the ignition switch is in LOCK (0) position, or the vehicle is in OFF mode. When you then turn the ignition switch back to ON (II), or press the engine start/stop button to select the ON mode, the daytime running lights will not come on until the parking brake is released.
- The headlights revert to normal operation when you turn them on with the headlight switch.