Theory of Operation
WARNING: This page is about a different car, the 2011 RAM Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The Diesel Exhaust Fluid (DEF) Dosing Control Unit is used to control the operation and monitoring of the Diesel Exhaust Fluid system. The DEF Dosing Control Unit shares information with the Powertrain Control Module over the J1939 Data Link.