Cobalt L4-2.0L SC VIN P (2005)
Daytime Running Lamp: Description and Operation
DAYTIME RUNNING LAMPS (DRL)
The ambient light sensor is a light sensitive transistor that varies its voltage signal to the body control module (BCM) in response to changes to the
outside (ambient) light level. When the BCM receives this signal, it will either turn ON the daytime running lamps (DRL) or the headlights if the
headlamp switch is in the AUTO position. Any function or condition that turns ON the headlights will cancel the DRL operation. With the headlight
switch in the AUTO position, the headlights will either be turned ON or OFF, after an approximate 30-second delay depending on whether daylight or
low light conditions are sensed. The DRL illuminates the park/turn signal and DRL lamps. The DRL will operate when the ignition switch is in the ON
position, the gear selector is not in the PARK position, and the parking brake is released. When these conditions have been met and the ambient light
sensor indicates daytime conditions, the DRL will illuminate.
DRL operation in manual transmission equipped vehicles will occur when the ignition switch is in the ON position, and the parking brake is released.
