Front Lamp Unit
| Refer to FRONT EXTERIOR LAMPS AND LIGHTING . |
The front lamp unit has a path to ground at all times through their connection to the engine compartment wire harness. The BCM monitors headlamp switch inputs to determine whether the headlamp high or low beams are selected. The BCM then controls headlamp illumination through relays soldered onto the BCM internal circuit board. When the BCM detects a change in headlamp beam selection, the BCM energizes or de-energizes a high side driver, which controls an output to the solenoid that operates the shutter in each headlamp. The BCM also sends the appropriate electronic messages to the IPC to control the illumination of the high beam indicator. The BCM remembers which beams (LOW or HIGH) were selected when the headlamps were last turned OFF, and energizes those beams again the next time the headlamps are turned ON. Each headlamp includes an integral reflector adjuster that is to be used for static aiming of the headlamps. The BCM will store a Diagnostic Trouble Code (DTC) for any shorts or opens in the headlamp circuits.