Theory Of Operation
WARNING: This page is about a different car, the 2015 RAM 3500 HD and 2015 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
The Ambient Temperature Sensor signal is a direct input to the Body Control Module (BCM). The BCM transmits the ambient temperature message to the Powertrain Control Module (PCM) over the CAN C bus.