Ambient Temp Sensor: Operation
WARNING: This page is about a different car, the 2003 Chrysler PT Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
The ambient temperature sensor is a variable resistor that operates on a five-volt reference signal. The resistance in the sensor changes as temperature changes, changing the temperature sensor signal circuit voltage to compass/temperature display unit. Based upon the resistance in the sensor, the compass/temperature display unit senses a specific voltage on the temperature sensor signal circuit, which it is programmed to correspond to a specific temperature. The compass/temperature display unit then displays the proper ambient temperature.