Theory Of Operation
WARNING: This page is about a different car, the 2006 Dodge Magnum, 2006 Dodge Charger, and 2006 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.
The Front Control Module receives a fuel level signal over CAN B from the Cluster Module. Once the message is received from the FCM, it passages the fuel level message via CAN C to the PCM.