See also:

Turn Signals when Towing a Trailer
The turn signal indicators on the instrument panel flash whenever signaling a turn or lane change. Properly hooked up, the trailer lamps also flash, telling other drivers the vehicle is turni ...

Lamp Messages
AFL (Adaptive Forward Lighting) LAMPS NEED SERVICE This message displays when the Adaptive Forward Lighting (AFL) system is disabled and needs service. See your dealer. See Adaptive Forwa ...

Add-on Electrical Equipment
The OnStar system is integrated into the electrical architecture of the vehicle. Do not add any electrical equipment. See Add-On Electrical Equipment. Added electrical equipment may interfer ...