Headlamp: Description and Operation

PRINCIPLES OF OPERATION

The autolamp system provides light-sensitive automatic on/off control of the headlamps and parking lamps controlled by the generic electronic module (GEM) when the autolamp switch is turned ON. When the ignition switch is turned to the RUN or START position with the autolamps feature already enabled and the ambient light level is dark, the GEM will request the headlamps and parking lamps be turned on. When the autolamps are disabled, the GEM will request the headlamps and parking lamps to be turned off, regardless of the ignition switch position.

When the autolamps have been enabled and the ignition switch is in the RUN/START position, the GEM will request that the exterior lamps be turned on or off based on ambient light level. If the vehicle enters darkness for at least 15 seconds, the GEM will request the exterior lamps on. If the vehicle enters light for at least 15 seconds, the GEM will request the exterior lamps off. By delaying turning on and off the exterior lamps during short periods of darkness and light, the vehicle security module prevents the exterior lamps from flashing on and off.