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 purpose of this monitor is to check if the Exhaust Gas Recirculation (EGR) flow is higher than commanded. The diagnostic closes the EGR valve, and limits the EGR Throttle Control Valve. It then looks at fresh air flow fraction and the difference in pressure between the Exhaust Gas Pressure sensor and Boost Pressure sensor to determine if the EGR valve is leaking. The Powertrain Control Module (PCM) will illuminate the MIL lamp after the diagnostic runs and fails in two consecutive drive cycles. The PCM will also illuminate the ETC lamp. The MIL lamp will turn off once the diagnostic runs and passes in 4 consecutive drive cycles.