Exhaust Gas Recirculation (EGR) Valve
WARNING: This page is about a different car, the 2012 Ford Pickup, 2012 Ford F550 Super Duty, 2012 Ford F450 Super Duty, and 2012 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The EGR valve is a variable position valve that controls the amount of exhaust that enters the intake manifold. The powertrain control valve (PCM) controls the EGR valve which operates between 0 and 100% duty cycles.
The EGR valve operation can be monitored by viewing the EGRVP PID which displays the EGR valve position. The EGR valve position sensor is integral the EGR valve.