Lighting and Horns: Description and Operation

EXTERIOR LIGHTING SYSTEM
Exterior Lighting Battery Saver
The BCM monitors the status of and controls the park lamp, head lamp and fog lamp relay's. If any exterior lamps are left ON after the ignition is turned OFF, the BCM will turn them OFF after 10 minutes.

Headlamp Delay
The headlamp time delay operates when the ignition switch is turned OFF while the headlamps are still ON, and the headlamps are then turned OFF within 45 seconds after the ignition is OFF. This will provide a 90-second time delay before turning OFF the headlamps.

Headlamp Switch
The headlight switch on LH vehicles use a multiplexed (MUX) circuit to the BCM. The BCM will then control the park lamp, head lamp and fog lamp relay's based on this input.

Fog Lamp Control
The body control module controls the operation of the fog lamp relay which controls the fog lamps. The fog lamps can only be ON if the park or low beam headlamps are ON. If the high beams are turned ON, the fog lamps will automatically be turned OFF.

Auto Headlamps
The headlamps and park/tail lamps will be activated by the BCM when the headlamp switch is in the auto mode. To activate the auto headlamps the BCM requires that: (1) the headlamp switch is in the 'A' position, (2) the engine is running, and (3) the light level sensed through the sun load sensor falls below the calibrated level.

INTERIOR LIGHTING
Courtesy Lamp Control
The body controller has direct control over the majority of the vehicle's courtesy lamps. The body computer will illuminate the courtesy lamps under any of the following conditions:
1. Any door is ajar.
2. The courtesy lamp switch on the instrument panel is closed.
3. A Remote Keyless entry unlock message is received. If the interior lamps are left ON after the ignition is turned OFF, the BCM will turn them OFF after 1 hour or until either the dome lamp switch or door ajar switch changes state.

Illuminated Entry
Illuminated entry will be initiated when the customer enters the vehicle by unlocking the doors with the key fob, or with the key if the vehicle is equipped with vehicle theft alarm. Upon exiting the vehicle, if the lock button is pressed with a door open, illuminated entry will cancel when the door closes. If the doors are closed and the ignition switch is turned ON, the illuminated entry also cancels.