EGR Valve: Description and Operation

The electronic EGR valve and solenoid assembly is attached to the front of the right cylinder head. An exhaust gas routing tube connects the EGR valve to the intake manifold.

Exhaust gas recirculation flow is determined by the Powertrain Control Module (PCM) and is controlled by an electronic EGR valve assembly. For a given set of conditions, the PCM knows the ideal exhaust gas recirculation flow to optimize NOx and fuel economy as a function of the pintle position. Pintle position is obtained from the position sensor. The PCM adjusts the duty cycle of 128 Hz power supplied to the solenoid coil to obtain the correct position. The electronic EGR valve assembly consists of a pintle, valve seat, and housing which contains and regulates exhaust gas flow. An armature, return spring, and solenoid coil provide the operating force to regulate exhaust gas flow by changing the pintle position. The solenoid coil assembly is wired in parallel with a diode that connects two internal connectors.