Outside Air Temperature
WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The ambient air temperature sensor is a 2-wire negative temperature co-efficient thermistor mounted underhood, the HVAC control module uses the signal sent by the ambient air temperature sensor to ensure optimal performance of the air conditioning system. The HVAC control module will also send the temperature information by way of a serial data message to the body control module which in turn sends a serial data message to the driver information center which will display the outside temperature in either degrees Celsius or Fahrenheit.