Daytime Running Lamps (DRL)

Battery positive voltage is applied at all times from the APPROACH fuse 2 in the underhood electrical center to both the coil side and switch side of the DRL R relay 38 and the DRL L relay 40 in the instrument panel electrical center. The ambient light sensor is a light sensitive transistor that varies its voltage signal to the BCM in response to changes to the outside (ambient) light level. The BCM will apply a ground to the coil side of the DRL L and DRL R relays. This energizes the relays and allows battery positive voltage to be applied from the switch side of the relays to the front turn signal lamps. The front turn signal lamps will be ON steady (non-flashing). 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 turn signal lamps will either be turned ON or OFF after a 30-second delay, depending on whether daylight or low light conditions are sensed. The DRL operates when the ignition switch is in the RUN position, and the parking brake is not set or the transmission is not in park. When these conditions have been met and the ambient light sensor indicates daytime conditions, the DRL will illuminate.