Headlights/Daytime Running Lights (DRL) Circuit

The Daytime Running Lamps (DRL) lights are controlled by the Body Control Module (BCM) via the DRL relay when the headlamp and panel dimmer switch is the AUTO position.

The vehicle is also equipped with automatic headlamps, which is activated when the photo sensor detects dark conditions. A code will set if there is a fault in the photo sensor, or in the two CKT's between the photo sensor and the body control module (BCM).

The DRL relay is fed by the gauges fuse through CKT 39 (PNK) when the ignition switch is in the run and crank position, (the coil side of the relay), and the Gauges fuse. The DRL relay is controlled by the BCM based on the input form the ambient light sensor via CKT 592 (LT GRN/BLK).

The relay supplies a ground path to the lights through CKT 544 (PPL) and through CKT 750 (BLK).

The DRL lights are on when the vehicle ignition switch is in the run position, and the park brake is not set, daylight conditions exists and the transmission has been in drive before placing in park. The DRL lights are turned off when the headlamp and panel dimmer switch is turned to the park or head position or the input to the BCM from the ambient light sensor signals that daylight conditions do not exist any more.

The DRL headlamps can be disabled by pressing the dome lamp override switch four times within a six second period. This will disable the DRL headlamps until the ignition is turned OFF. The DRL headlamps will return to normal operation when the ignition is recycled.