Conditions for Setting the DTC

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

When the BCM receives a command to illuminate the low beam or DRL headlamps and the low beam headlamp driver module control circuit is open or shorted to voltage.
When the BCM does not receive a command to illuminate the low beam or DRL headlamps and the low beam headlamp driver module control circuit is shorted to ground.