Daytime Running Lamps (DRL)

The Daytime Running Lamps (DRL) control module is designed to automatically operate the exterior lights depending on outside light conditions. The DRL control module operates in two modes: the day mode and the low light mode. In the day mode, when the DRL ambient light sensor senses daylight, the DRL control module turns on the low beam headlamps at reduced intensity under the following conditions:
^ The ignition is in RUN.
^ The headlamps are off.
^ The park brake is OFF.

In the low light mode, when the DRL ambient light sensor senses darkness, the DRL control module then turns on the low beam headlamps to full intensity through circuit 10 and turns on the park, side marker, license, and tail lamps through circuit 9. If the engine should stall with the DRL control module in the low light mode, the DRL control module turns off the headlamps and leaves the side marker, park, license and tail lamps on while the engine is being cranked. The headlamp and instrument panel lamp dimmer switch operates as usual. The DRL control module receives voltage from the DRL Fuse through circuit 1239 and the DIC/HVAC Fuse through circuit 541. The park lamps and/or the headlamps may be operated manually at any time by using the headlamp switch and headlamp dimmer switch. The DRL module will not operate if the system voltage is less then 9 volts or greater than 18 volts.