2005 GMC Sierra 1500 Pickup Owner's Manual - Page 177

If you apply your brakes, the cruise control will shut off. Setting Cruise Control {CAUTION: Cruise control can be dangerous where you cannot drive safely at a steady speed. So, do not use your cruise control on winding roads or in heavy traffic. Cruise control can be dangerous on slippery roads. On such roads, fast changes in tire traction can cause needless wheel spinning, and you could lose control. Do not use cruise control on slippery roads. {CAUTION: If you leave your cruise control on when you are not using cruise, you might hit a button and go into cruise when you do not want to. You could be startled and even lose control. Keep the cruise control switch off until you want to use cruise control. 1. Move the cruise control switch to on. 2. Get up to the speed you want. 3. Press in the set button at the end of the lever and release it. 4. Take your foot off the accelerator pedal. The cruise symbol on the instrument panel will illuminate when the cruise control is engaged. 3-11