2010 Hummer H3 Owner's Manual - Page 183

Climate Controls 8-3 @ (Recirculation): Press to turn the recirculation mode on or off. An indicator light comes on when the recirculation is on. This mode recirculates and helps to quickly cool the air inside the vehicle. It can be used to prevent outside air and odors from entering the vehicle. Recirculation is available in the bi-level and vent modes. This mode cannot be selected while in the floor, floor/defog or defrost modes. If you try to select the recirculation mode, the indicator flashes three times indicating it is not available in that mode. When the recirculation mode is turned on, the air conditioning turns on automatically. When it is hot enough outside, the recirculation mode may turn on automatically to help improve cooling performance. The indicator light will be lit to show this mode is active. If the recirculation button is pressed while in this mode, the light flashes three times and stays on to indicate that recirculation may not be shut off. = (Rear Defogger): Press to turn the rear window defogger on or off. After the button is first pressed the rear window defogger stays on for about 15 minutes. If turned on again, the defogger only runs for about seven and one-half minutes. 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 the vehicle warranty. Do not attach a temporary vehicle license, tape, a decal or anything similar to the defogger grid. Rear Window Defogger The rear window defogger uses a warming grid to remove fog or frost from the rear window when the key is in the ignition and turned to ON/RUN.