Parking Lamp: Description and Operation

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 night time conditions (night mode). Light levels are detected by the ambient light sensor, a light sensitive transistor that varies its voltage signal to the 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 automatic 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 automatic 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.

PARK, TAIL AND MARKER LAMPS
The park, tail and marker lamps, including the license lamps, are illuminated when the headlamp switch is placed in the PARK or HEAD position. The PARK fuse in the BCM supplies battery positive voltage to the headlamp switch. When the headlamp switch is placed in the PARK or HEAD position, the headlamp switch supplies voltage to the park lamp supply voltage circuit. The park lamp supply voltage circuit goes from the headlamp switch, to the BCM, and then to the park, tail and marker lamps. The park, tail, and marker lamps receive a ground at G101, G401, or G403.