Daytime Running Lights
WARNING: This page is about a different car, the 2002 Pontiac Sunfire, 2002 Chevrolet Cavalier, 2001 Pontiac Sunfire, and 2001 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
Body Control Module (BCM) controls Daytime Running Lights (DRL) function by supplying system ground. DRL is activated when park brake is off, transaxle is not in Park, and headlight switch is off.