2003 GMC Envoy Owner's Manual - Page 154

If yourvehicle has therear seat audio system, the lower buttons are used to adjust the rear seat comfort controls. The temperature of the air coming through the rear outlets is determined by the front passenger's temperature setting. The button with the up and down arrows on it regulates the fan speed. The mode button can be used to change the direction of airflow (upper, bi-level or floor) to the rear seat area. To turn the rear comfort controls off, press the lower PWR button. Outlet Adjustment Your vehicle may have rear seat outlets that can be used to adjust the airflow toward either seating area, the floor or upward. Move the control in the center of each outlet in any direction to direct airflow. 3-29