2007 GMC Sierra 1500 Pickup Owner's Manual - Page 11

Power Lumbar Your vehicle may have this feature. The control is located on the outboard side of the seat cushion. Heated Seats If your vehicle has this feature, the buttons are located on the front doors. The engine must be running for the heated seats to work. To increase or decrease support, hold the control forward or rearward. Keep in mind that as your seating position changes, as it may during long trips, so should the position of your lumbar support. Adjust the seat as needed. To heat the entire seat, press the horizontal button with the heated seat and seatback symbol. Press the button to cycle through the temperature settings of high, medium and low and to turn the heated seat off. Indicator lights will come on to designate the level of heat selected: three for high, two for medium, and one for low. 11