2012 GMC Sierra Owner's Manual - Page 203

Lighting 6-3 Headlamp High/ Low-Beam Changer 5 3 (Headlamp High/Low Beam Changer): To change the headlamps from low to high beam, push the lever toward the instrument panel. To return to low-beam headlamps, pull the multifunction lever toward you. Then release it. To use it, pull the turn signal lever toward you, then release it. If the headlamps are in the automatic position or on low beam, the high-beam headlamps will turn on. They will stay on as long as you hold the lever toward you. The high-beam indicator on the instrument panel cluster will come on. Release the lever to return to normal operation. . . The transmission is not in Park. The light sensor determines it is daytime. When the DRL system is on, only the DRL lamps are on. The taillamps, sidemarker, instrument panel lights, and other lamps will not be on. When it begins to get dark, the automatic headlamp system switches from DRL to the headlamps. To turn off the DRL lamps, turn the exterior lamps control to the OFF position and then release. For vehicles first sold in Canada, the transmission must be in the P (Park) position before the DRL lamps can be turned off. Daytime Running Lamps (DRL) When the high beams are on, this indicator light on the instrument panel cluster will also be on. Daytime Running Lamps (DRL) can make it easier for others to see the front of your vehicle during the day. Fully functional daytime running lamps are required on all vehicles first sold in Canada. The DRL system comes on when the following conditions are met: . . Flash-to-Pass This feature lets you use the high-beam headlamps to signal a driver in front of you that you want to pass. It works even if the headlamps are in the automatic position. The ignition is on. The exterior lamps control is in AUTO.