2008 GMC Acadia Owner's Manual - Page 177

To clear fog from the rear seat side windows, select the bi-level mode on the rear climate control system and direct the headliner outlets toward the side windows. Rear Window Defogger The rear window defogger uses a warming grid to remove fog from the rear window. 0 (Defrost): Press this button to remove fog or frost from the windshield more quickly. This mode directs most of the air to the windshield and side window vents and some to the floor vents. In this mode, the system automatically forces outside air into the vehicle. The recirculation mode cannot be selected while in the defrost mode. The air conditioning compressor runs automatically in this setting, unless the outside temperature is close to freezing. Do not drive the vehicle until all the windows are clear. While in defrost mode, if the PASS button is pressed, the PASS button indicator will flash three times to let you know that the passenger climate control system cannot be activated. If the passenger temperature buttons are adjusted while in defrost mode, the driver temperature indicator will change. The passenger temperature will not be displayed. AUX (Auxiliary): Press this button to turn the rear heating and air conditioning on. See Rear Air Conditioning and Heating System on page 3-36 or Rear Air Conditioning and Heating System and Electronic Climate Controls on page 3-38. < (Rear Window Defogger): Press this button to turn the rear window defogger on or off. The rear window defogger stays on for about 10 minutes after the button is pressed, before turning off. The defogger can also be turned off by pressing the button again or by turning off the engine. Do not drive the vehicle until all the windows are clear. If your vehicle has heated outside rearview mirrors, the mirrors will heat to help clear fog or frost from the surface of the mirror when the rear window defog button is pressed. Notice: Do not use a razor blade or sharp object to clear the inside rear window. Do not adhere anything to the defogger grid lines in the rear glass. These actions may damage the rear defogger. Repairs would not be covered by your warranty. 3-35