2008 Chevrolet Impala Owner's Manual - Page 149

Rear Window Defogger The rear window defogger uses a warming grid to remove fog from the rear window. Outlet Adjustment Use the thumbwheel located below or to the side of the outlet, to change the direction of the air flow. < (Rear Window Defogger): The rear window defogger turns off automatically after it has been activated for 10 minutes. It can be turned off manually, by pressing the button again or by turning the ignition to the LOCK/OFF position. If additional window clearing is required, the rear window defogger can be turned on again for additional window clearing. The length of defogger operation will increase if the vehicle is being driven. 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. See Outside Power Mirrors on page 2-37. Operation Tips • Clear away any ice, snow or leaves from the air inlets at the base of the windshield that may block the flow of air into your vehicle. • Use of non-GM approved hood deflectors may adversely affect the performance of the system. • Keep the path under the front seats clear of objects to help circulate the air inside your vehicle more effectively. • If the airflow seems low when the fan is at the highest setting, the passenger compartment air filter, if equipped, may need to replaced. For more information, see Passenger Compartment Air Filter on page 3-26 and Scheduled Maintenance on page 6-4. Do not drive the vehicle until all the windows are clear. 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. • If fogging reoccurs while in vent or bi-level modes with mild temperature throughout the vehicle, turn on the air conditioner to reduce windshield fogging. 3-25