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 Airflow Control Valve controlled by the Powertrain Control Module (PCM) and is actuated by an electric motor. A spring internal to the actuator assembly attempts to drive the valve to the fully-open position. The electric motor works to overcome the spring force when the engine control module commands the valve to close. Position feedback from the valve is sent to the PCM to allow for closed-loop control. Discrepancy in position feedback sent to the PCM, and commanded position sent to the EGR Airflow Control Valve by more than a prescribed amount will result in failure of device rationality diagnostics. Failure to properly actuate the EGR Airflow Control Valve can result in poor engine performance. The PCM will illuminate the MIL lamp after the diagnostic runs and fails in two consecutive drive cycles. This may cause active Exhaust Aftertreatment regenerations to last longer. The PCM will turn off the MIL lamp after the diagnostic runs and passes in 4 consecutive drive cycles.