EGR Valve: Description and Operation

EGR Valve And Sensor Assembly:

LOCATION/CONSTRUCTION
The EGR valve, generally located at one side of the engine toward the top, is equipped with a position sensor.

OPERATION
The EGR valve Position (EVP) sensor sends a voltage signal to the Powertrain Control Module (PCM) in relation to the opening of the EGR valve.

The valve is actuated and controlled by vacuum, supplied from the EGR Vacuum Regulator (EVR). When vacuum from the EVR overcomes diaphragm spring pressure, the diaphragm lifts the pintle valve from its seat, allowing exhaust gases to recirculate.

The PCM regulates EGR flow based on engine load, temperature, and current EGR valve opening and/or flow.

NOTE: The EVP Sensor and EGR valve are non-serviceable and must be replaced individually.