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 EGR Valve position is monitored by the Powertrain Control Module (PCM). The purpose of this monitor is compare the EGR Valve actual position to position commanded by the PCM. If these values differ by a significant value for an extended period of time in two consecutive drive cycles, the PCM will turn on the MIL Light, and EGR flow will be disabled.