Ambient Temperature Sensor: Operation
WARNING: This page is about a different car, the 2005 Dodge SX, 2005 Dodge SRT-4, and 2005 Dodge Neon. 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 sent to it by the NGC engine controller. The resistance in the sensor changes as temperature changes, changing the temperature sensor signal circuit voltage to the NGC engine controller. Based upon the resistance in the sensor, the mirror senses a specific voltage on the temperature sensor signal circuit, which it is programmed to correspond to a specific temperature.