2012 GMC Sierra Owner's Manual - Page 202

6-2 Lighting the delay can be changed using the DIC. See Driver Information Center (DIC) on page 5‑30 10 minutes after the ignition is turned off. When the headlamps are turned on while the vehicle is off, the headlamps will stay on for 10 minutes before automatically turning off to prevent the battery from being drained. Turn the headlamp control to off and then back to the headlamp on position to make the headlamps stay on for an additional 10 minutes. Push the turn signal/multifunction lever toward the instrument panel to change the headlamps from low beam to high beam. The exterior lamps control has four positions: O (Off): Turns off the automatic headlamps and Daytime Running Lamps (DRL). Turn the headlamp control to the off position again to turn the automatic headlamps or DRL back on. For vehicles first sold in Canada, the off position will only work when the vehicle is shifted into P (Park). AUTO (Automatic): Automatically turns on the headlamps at normal brightness, together with the following: ... ; (Parking Lamps): ... Turns on the parking lamps together with the following: Instrument Panel Lights Taillamps License Plate Lamps Roof Marker Lamps (If Equipped) 2 (Headlamps): ... Turns on the headlamps together with the following: Parking Lamps Instrument Panel Lights Taillamps License Plate Lamps Roof Marker Lamps (If Equipped) Parking Lamps Instrument Panel Lights Taillamps License Plate Lamps Roof Marker Lamps (If Equipped) Exterior Lamps Off Reminder For vehicles with a radio, a reminder chime sounds when the headlamps or parking lamps are manually turned on, the ignition is off, and a door is open. To disable the chime, turn the lamp off. When the vehicle is turned off and the headlamps are in AUTO, the headlamps may automatically remain on for a set time. The time of When the headlamps are turned on while the vehicle is on, the headlamps turn off automatically