Rear Temperature Sensor
WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.
The rear temperature sensor, located in the rear of the headliner next to the active noise control microphone, contains a thermistor and is an input to the FCIM. The sensor varies its resistance with the temperature. As the temperature rises, the resistance falls. As the temperature falls, the resistance rises. The FCIM uses the sensor information to help maintain the desired temperature of the rear passenger cabin air.