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 relay is fed by the IGN E fuse when the ignition switch is in the run and crank position, (the coil side of the relay), and the DRL fuse which is hot at all times. The DRL relay is controlled by the BCM based on the input form the ambient light sensor via CKT 592.

The relay supplies current to the lights through CKT 545 and ground through CKT 150 and ground G100 and G101.

The DRL lights are on when the vehicle ignition switch is in the run position, 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 does not exists any more.