2008 GMC Envoy Owner's Manual - Page 156

Driver's Side Temperature Lever: The lever on the left side of the climate control panel is used to raise or lower the temperature on the driver's side of the vehicle. Slide the lever up or down to adjust the temperature. Passenger's Side Temperature Lever: The lever on the right side of the climate control panel is used to raise or lower the temperature on the passenger's side of the vehicle. Slide the lever up or down to adjust the temperature. This lever also adjusts the temperature to the rear seat outlets. When the temperature outside is 0°F (−18°C) or lower, use the engine coolant heater, if the vehicle has one, to provide warmer air, faster to your vehicle. Defogging and Defrosting Fog on the inside of windows is a result of high humidity (moisture) condensing on the cool window glass. This can be minimized if the climate control system is used properly. There are two modes to choose from to clear fog or frost from your windshield. Use the defog mode to clear the windows of fog or moisture and warm the passengers. Use the defrost mode to remove fog or frost from the windshield more quickly. Turn the right knob clockwise or counterclockwise to select one of the following modes: - (Defog): # (Air Conditioning): Press this button to turn the air-conditioning system on or off. When the button is pressed, an indicator light will come on and the system will begin to cool and dehumidify the air inside of the vehicle. You may notice a slight change in engine performance when the air conditioning compressor shuts off and turns on again. This is normal. This mode directs the air to the floor outlets, windshield and side window outlets. The recirculation button cannot be selected while in defog mode. This mode directs most of the air to the windshield and the side window outlets, with only a little air directed to the floor outlets. The air conditioning compressor may run to dehumidify the air to prevent window fogging. The recirculation button cannot be selected while in defrost mode. Do not drive the vehicle until all the windows are clear. 1 (Defrost): 3-22