04-17-2013, 02:52 PM
|
#21
|
Moderator
Join Date: Nov 2004
Location: Long Grove, IL
Posts: 5,002
|
Quote:
Originally Posted by GM
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 lights (DRL) or the headlights. Any function or condition that turns on the headlights will cancel the daytime running lamps operation. With the headlight switch in the OFF 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 HTR A/C IGN fuse in the underhood junction block supplies ignition positive voltage to the daytime running lamp (DRL) relay coil circuit. The DRL relay switch contacts are connected to the low beam circuit. When the headlamp switch is placed in the OFF position, the BCM will either turn on or off the daytime running lamps, depending on whether daylight or low light conditions are sensed. The BCM energizes the DRL relay, closing the switch contacts and grounding the low beam circuit. Ground is provided at G201. The DRL illuminate the low beam headlights at a reduced intensity. 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.
|
.....
__________________
Cliff Scott
2004 Alero GX w/sport pkg - Sold, living somewhere in WI now.
2011 Saab 9-5 Turbo4 M6
2004 Corvette Convertible M6
1994 Chevy Beretta - Quad4/M5
|
|
|