Sensor-Ambient Air Temperature: Operation
WARNING: This page is about a different car, the 2005 Dodge Pickup and 2005 Dodge Cab & Chassis. 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 by the Front Control Module (FCM). The resistance in the sensor changes as temperature changes, changing the temperature sensor signal circuit voltage to the FCM. Based upon the resistance in the sensor, the FCM senses a specific voltage on the temperature sensor signal circuit. The FCM then translates the voltage into a temperature reading that it sent over the Programmable Communications Interface (PCI) data bus circuit to other modules utilizing temperature information.