Daytime Running Lamps (DRL)

The ambient light sensor is a light sensitive transistor that varies its voltage signal to the Body Control Module (BCM) in response to changes to the outside (ambient) light level. When the BCM receives this signal it will either turn on the Daytime Running Lamps (DRL) or the headlights for auto headlamp operation. Any function or condition that turns on the headlights will cancel the daytime running lamps operation. With the headlight switch in the OFF position, the headlights will either be turned ON or OFF, after an approximate 8 second delay depending on whether daylight or low light conditions are sensed. The DRL will operate when the ignition switch is in the RUN position, the gear selector is not in the PARK position and the parking brake is released.

When these conditions have been met and the ambient light sensor indicates daytime conditions, the DRL will illuminate.

The DRL relay is supplied battery positive voltage by the GAUGES fuse in the IP fuse block. When the BCM requests DRL operation, the DRL relay coil is grounded by the BCM activating the relay. The energized DRL relay bypasses the multifunction headlamp dimmer switch by rerouting ground G110 directly to both low beam headlamp bulbs.

The Automatic Lamp Control (ALC) system and the daytime running lamps (DRL) feature (except the Canadian version) can be temporarily disabled by performing the following procedure:
1. Turn the ignition to RUN.
2. Press the DOME OVERRIDE button four times within six seconds.

A chime will sound informing you that the system is off. The system will remain disabled until the ignition is cycled off and then on or by pressing the DOME OVERRIDE button four more times within six seconds. The chime will sound again signaling that the system has been reactivated.

The export vehicle is not equipped with the DRL feature.