2008 GMC Sierra 1500 Pickup Owner's Manual - Page 153

If the vehicle is started in a dark garage, the automatic headlamp system will come on immediately. Once the vehicle leaves the garage, it takes approximately one minute for the automatic headlamp system to change to DRL if it is bright enough outside. During that delay, the instrument panel cluster may not be as bright as usual. Make sure the instrument panel brightness control is in the full bright position. See Instrument Panel Brightness on page 3-18. To idle the vehicle with the automatic headlamp system off, turn the control to the off position. The headlamps will also stay on after you exit the vehicle. This feature can be programmed using the Driver Information Center (DIC). See DIC Vehicle Customization (With DIC Buttons) on page 3-68. The regular headlamp system can be turned on when needed. Fog Lamps The vehicle's fog lamps provide better visibility in foggy or misty conditions. The fog lamp button is located on the left side of the instrument panel. The parking lamps and/or low-beam headlamps must be on for the fog lamps to work. Press the button to turn the fog lamps on while the headlamps are on. Press the button again to turn them off. An indicator light in the button comes on when the fog lamps are in use. Remember, fog lamps alone do not give off as much light as the headlamps. Never use the fog lamps in the dark without turning on the headlamps. The fog lamps go off whenever the high-beam headlamps come on. When the high beams turn off, the fog lamps come on again. 3-17 Puddle Lamps If your vehicle has puddle lamps, they come on when the unlock button on the Remote Keyless Entry (RKE) Transmitter is pressed. The lamps time out or turn off once the engine is started.