Theory Of Operation
WARNING: This page is about a different car, the 2014 RAM 1500. However, it is still accessible from the selected car via links, so may be relevant.
The Powertrain Control Module (PCM) utilizes Fuel quantity Balancing Control (FBC) to monitor rationality failures. The task of FBC is to minimize speed variations in idle operation and in the lower engine speed range. The FBC evaluates oscillations of the engine speed signal in order to determine cylinder specific fuel quantity correction. The diagnostic continuously monitors these correction quantities for each every individual cylinder.