Owners of a 2010 Buick LaCrosse may complain that the right side low beam headlamp is inoperative.
First, check for a possible blown BCM 4 fuse. This fuse is #9 in the IP Fuse Center (BCM 4).
This condition may also cause codes B2699.01 and/or B2699.04 to set.
It is possible for the wiring going to the right side headlight to become rubbed through by the generator pulley. Inspect the generator pulley area for wires (blue or tan) to be shorted. Repair wiring as necessary and zip-tie the harness out of the way of the pulley.