2008 Subaru Impreza Owner's Manual - Page 157
2008 Subaru Impreza Manual
Page 157 highlights
Instruments and controls 3-41 Windshield wiper deicer (if equipped) The windshield wiper deicer operates only when the ignition switch is in the "ON" position. Before turning on the windshield wiper deicer, remove any snow from the windshield. To turn on the windshield wiper deicer, push the button. The indicator light located on the button lights up while the windshield wiper deicer is operating. The windshield wiper deicer will automatically shut off after approximately 15 minutes. If the windshield wiper blades have been deiced completely before that time, push the button to turn it off. It also turns off when the ignition switch is turned to the "Acc" or "LOCK" position. If deicing is not complete when you restart your vehicle, you have to push the button to turn the deicer on again. Your SUBARU dealer can set your windshield wiper deicer for continuous operation. Contact your SUBARU dealer for details. Once the windshield wiper deicer has been set for continuous operation, pressing the button results in continuous operation. The windshield wiper deicer automatically stops operating if any one of the following conditions occurs during continuous operation. . The outside temperature becomes 418F (58C) or higher. . The vehicle speed remains at 9 mph (15 km/h) or lower for 15 minutes. . The battery voltage decreases below the permissible level. CAUTION To prevent the battery from being discharged, do not operate the windshield wiper deicer continuously for any longer than necessary. NOTE If your vehicle is equipped with the outside mirror defogger, the outside mirror defogger operates while the windshield wiper deicer is operating. Manual climate control system Automatic climate control system