2007 Chevrolet Silverado 1500 Pickup Owner's Manual - Page 240

There is also an exterior temperature sensor located behind the front grille. This sensor reads the outside air temperature and helps maintain the temperature inside the vehicle. Any cover on the front of the vehicle could cause a false reading in the displayed temperature. In order to prevent false temperature readings at startup, the displayed temperature will not change until the following occurs: • Vehicle speed is above 10 mph (16 kmh) for 5 minutes. • Vehicle speed is above 32 mph (51 kmh) for 2 and a half minutes. The climate control system uses the information from these sensors to maintain your comfort setting by adjusting the outlet temperature, fan speed, and the air delivery mode. The system may also supply cooler air to the side of the vehicle facing the sun. The recirculation mode will also be used as needed to maintain cool outlet temperatures. Defogging and Defrosting You can use either defog or front defrost to clear fog or frost from your windshield. Use the defog mode to clear the windows of fog or moisture. Use the front defrost button to defrost the front windshield. - (Defog): Use this setting to clear the windows of fog or moisture. Press the mode button to select this setting. This setting will deliver air to the floor and windshield outlets. 0 (Front Defrost): Press the front defrost button to defrost the windshield. The system will automatically control the fan speed if you select defrost from AUTO mode. If the outside temperature is 40°F (4°C) or warmer, your air conditioning compressor will automatically run to help dehumidify the air and dry the windshield. Rear Window Defogger If your vehicle has this feature, the rear window defogger uses a warming grid to remove fog from the rear window. If your vehicle has a sliding rear window, you will not have a rear window defogger. 240