2006 GMC Yukon Owner's Manual - Page 185

Rear Window Defogger The lines you see on the rear window warm the glass. The rear window defogger uses a warming grid to remove fog from the rear window. Dual Automatic Climate Control System With this system, you can control the heating, cooling and ventilation in your vehicle. Your vehicle also has a flow-through ventilation system described later in this section. < (Rear): Press this button to turn the rear window defogger on or off. An indicator light in the button will come on to let you know that the rear window defogger is activated. The rear window defogger will automatically turn off several minutes after the button is pressed. Pressing the button while the defogger is running can also turn off the defogger. If your vehicle is equipped with heated mirrors this button will activate them. Notice: Do not use anything sharp on the inside of the rear window. If you do, you could cut or damage the warming grid, and the repairs would not be covered by your warranty. Do not attach a temporary vehicle license, tape, a decal or anything similar to the defogger grid. You can select different climate control settings for the driver and passengers. 3-25