2008 GMC Envoy Owner's Manual - Page 8

Power Lumbar On vehicles with power lumbar, the control is located on the outboard side of the seat. Heated Seats Your vehicle may have heated front seats. The buttons used to control this feature are located on the front door armrests. The engine must be running for the heated seat feature to work. To increase or decrease support, hold the control forward or rearward. 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. The indicator lights above the button will come on to designate the level of heat selected: three for high, two for medium, and one for low. The low setting warms the seatback and seat cushion until the seat temperature is near body temperature. The medium and high settings heat the seatback and seat cushion to a slightly higher temperature. You will be able to feel heat in about two minutes. 1-4