2009 Chevrolet Suburban Owner's Manual - Page 217

Rear Window Defogger The rear window defogger uses a warming grid to remove fog from the rear window. Sensors < (Rear Window Defogger): Press to turn the rear window defogger on or off. It automatically turns off several minutes after it has been activated. The defogger can also be turned off by turning off the engine. Do not drive the vehicle until all the windows are clear. 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. Heated Mirrors: For vehicles with heated outside rearview mirrors, the mirrors heat to help clear fog or frost from the surface of the mirror when the rear window defog button is pressed. See Outside Power Mirrors on page 2-53. The solar sensor, located in the defrost grille in the middle of the instrument panel, monitors the solar heat. Do not cover the solar sensor or the system will not work properly. 3-29