Automatic Headlamps and Park Lamps

The automatic headlamps and park lamps are designed to automatically illuminate when the ignition is ON and the outside (ambient) light level is low as in nighttime conditions (night mode). Light levels are detected by the ambient light sensor, a light sensitive transistor that varies its voltage signal to the Body Control Module (BCM) in response to changes to the ambient light level. When the BCM receives a low light mode signal from the ambient light sensor it will then energize the park lamp and headlamp , relays illuminating the headlamps and park lamps. The DRL lamps will not operate when the automatic headlamps and park lamps are on.

In the low light mode, the ambient light sensor detects low light level, the BCM turns OFF the front turn signal lamps and grounds the park lamp relay and headlamp relay control circuits, turning ON the headlamps and park lamps under the following conditions:
^ The ignition switch is in the RUN position.
^ The headlamps are OFF.
^ The park brake is OFF (released).

If the engine stalls with the DRL in the low light mode, the BCM turns OFF the headlamps while the engine is being cranked. The park lamps will remain ON while the engine is being cranked.