2002 GMC Envoy Owner's Manual - Page 184

Rear Comfort Controls Your vehicle has one of the following rear comfort control systems. With either system, the rear comfort controls will be disabled when the front comfort control system is in defrost. This occurs to provide maximum airflow to clear the windshield. The temperature of the air coming through the rear outlets is determined by the front passenger's temperature setting. Press the PWR button to turn the rear comfort controls on and off. Use the mode knob to change the direction of airflow (upper, bi-level or floor) to the rear seat area. If your vehicle has the rear 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. 3-10