Daytime Running Lamps

Vehicles equipped with the DRL feature illuminate the high beam filament of both headlamp bulbs at a reduced intensity when the engine is running, the parking brake is released, the headlamps are turned OFF, and the optional automatic transmission gear selector lever is in any position except PARK. The park lamps may be ON or OFF for DRL to operate. For vehicles with a manual transmission, the DRL will operate in any transmission gear selector lever position. The BCM must be programmed appropriately for this feature to be enabled.

Once enabled, anytime the BCM receives electronic messages over the CAN data bus from the PCM indicating the engine is running, from the IPC indicating the status of the left (lighting) multifunction switch is in any position except headlamps ON and the parking brake lever is released, and from the TCM indicating the automatic transmission gear selector lever is in any position except PARK, the BCM provides a pulse width modulated voltage output to the headlamp high beam bulb filaments through high side drivers on the right and left high beam feed circuits to produce illumination at a reduced intensity.