Theory Of Operation
WARNING: This page is about a different car, the 2019 RAM 3500 HD and 2019 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
The Fuel Level Sensor signal is a direct input to the Body Control Module (BCM). The BCM transmits the fuel level message to the Powertrain Control Module (PCM) over the CAN C bus.