2008 Pontiac Grand Prix Owner's Manual - Page 145

Recirculation cannot be selected when in this mode even though the indicator light comes on when the recirculation button is pressed. The middle knob on the climate control panel can also be used to select the defog or defrost mode. This mode will automatically use outside air. The air conditioning compressor will be engaged unless the outside temperature is 40°F (4°C) or below. Recirculation cannot be selected when in this mode even though the indicator light comes on when the recirculation button is pressed. Defogging and Defrosting Fog on the inside of the vehicle is a result of high humidity causing moisture to condense on the cool window glass. This can be minimized if the climate control system is used properly. There are two modes to clear frost or fog from the windshield. Use the defog mode to clear the windows of condensation and to warm the vehicle's occupants. Use the defrost mode to remove frost or condensation from the windshield quickly. See "Rear Window Defogger" later in this section for information on clearing the rear window of fog or ice. 1 (Defrost): Use the defrost mode to remove fog or frost from the windshield more quickly. This mode directs most of the air to the windshield and the side window outlets, with some air directed to the floor outlets. This mode has a timer and will shut off after five minutes. This mode will automatically use outside air. The air conditioning compressor will be engaged unless the outside temperature is 40°F (4°C) or below. Recirculation cannot be selected when in this mode even though the indicator light comes on when the recirculation button is pressed. . (Floor/Defog): Use the floor/defog mode to clear the windows of fog or moisture and to warm the passengers. This mode directs the air equally between the windshield and the floor outlets, along with some directed to the side window outlets. 3-29