Daytime Running Lamp: Description and Operation

DAYTIME RUNNING LAMPS (DRL)

The Daytime Running Lamps (DRL) illuminate the high beam headlights at a reduced intensity. When the headlight switch in the OFF position, ignition switch is in the ON position, and the transmission is shifted out of the PARK position, the high beam headlights will either be turned ON or OFF, after an approximate 30 second delay depending on whether daylight or low light conditions are sensed. When these conditions have been met and the ambient light sensor indicates daytime conditions, the DRL will illuminate. Any function or condition that turns on the headlights will cancel the daytime running lamps operation. Voltage is applied to the DRL relay at all times. The BCM sends a ground signal to the DRL relay coil when the ignition is in the ON position and the transmission is shifted out of the PARK position, energizing the DRL relay. When the DRL relay is energized, voltage is applied to the LH high beam headlamp. The LH high beam headlamp is wired in series with the RH high beam headlamp and the high beam headlamps illuminate at a reduced intensity. When the headlamp switch is in the HEAD or PARK position, the BCM will not energize the DRL relay.