2001 GMC Sierra 1500 Pickup Owner's Manual - Page 16

Manual Lumbar Control (If Equipped) If your vehicle has a lumbar adjustment, you can increase or decrease lumbar support in an area of the lower seatback. It is located on the outboard side of the seat cushion. Power Seat(s) (If Equipped) To increase or decrease support, turn the knob toward the front or rear of the vehicle. Horizontal Control: If your vehicle has a power seat, you can adjust it with this control located on the outboard edge of the seat. Raise or lower the front of the seat by raising or lowering the forward edge of the button. Raise or lower the rear of the seat by raising or lowering the rear edge of the button. 1-3