High Beam Headlamps

WARNING: This page is about a different car, the 2007 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.

The high beam headlamps for this vehicle does not use separate high beam bulbs. Instead it uses a high beam solenoid with a shutter to re-direct the low beam headlamps for high beam use

When the headlamp dimmer switch is placed in the high beam position, ground from G300 is applied through the dimmer switch and the headlamp dimmer switch signal circuit to the BCM signaling the headlamp high beam request. In response to this signal, the BCM applies ground through the high beam relay control circuit energizing the HIGH BEAM PCB Relay. With the high beam relay energized, battery voltage is applied through the switch side of the relay, the left and right high beam fuses, and the high beam supply voltage circuits to the headlamp high beam solenoids re-directing the low beams for high beam operation. At the same time the BCM sends a GMLAN serial data message to the instrument panel cluster (IPC) requesting the IPC to illuminate the high beam indicator. Ground for the left and right headlamps is provided at G104.