System Operation

Autolamps

System Operation

System Diagram





Network Message Chart

BCM (Body Control Module) Network Input Messages






Autolamps

The BCM (Body Control Module) monitors the light sensor with a voltage signal. The light sensor input to the BCM (Body Control Module) varies with the ambient light conditions.

When the BCM (Body Control Module) receives a headlamp switch status message from the FLM (Front Lighting Control Module) indicating a request for the autolamps, the BCM (Body Control Module) monitors the light sensor for the ambient light condition. If the BCM (Body Control Module) determines the ambient light level is dark, the BCM (Body Control Module) supplies voltage to the exterior lamps.

If the vehicle enters a dark/lighted area (such as when entering/exiting a non-lighted tunnel during the daytime), the transition from light to dark (or dark to light) needs to last 15 seconds before the BCM (Body Control Module) turns the exterior lamps on or off. This strategy prevents the exterior lamps from unnecessarily flashing on and off.

The BCM (Body Control Module) reacts quicker under extreme light conditions. If the BCM (Body Control Module) has detected a very dark condition, the exterior lamps are turned on after 1.5 seconds. If the BCM (Body Control Module) has detected a very high ambient light level, the exterior lamps are turned off after 4 seconds.

Headlamps On With Wipers On Function

When the headlamp switch is in the AUTOLAMPS ON position, the exterior lamps turn on when the front wipers are on for more than 3 seconds (if wipers are turned on manually) or 30 seconds (if the wipers are on from the rain sensing wiper system). This feature does not activate the exterior lamps during a mist wipe or while the wipers are on to clear washer fluid during a wash condition.

The exterior lamps turn off when the ignition is changed to OFF or ACCESSORY, the headlamp switch is placed in the OFF position, or the front wipers are off for more than 30 seconds (60 seconds if on from the rain sensing wiper system). The exception to this is when the exterior lights are on because of darkness determined by the light sensor.