Exhaust Gas Recirculation: Description and Operation

Typical Electronic EGR System:

OPERATION
The Exhaust Gas Recirculation (EGR) system is controlled by the Powertrain Control Module (PCM), based on return signals from various engine components.

The EGR system utilizes a valve position sensor, and a solenoid-type vacuum regulator device. Circuit power is supplied through the PCM power relay, and circuit ground is provided internally by the PCM.

The EGR Valve Position (EVP) Sensor informs the PCM of the EGR valve's position through a voltage return signal. This signal is directly proportional to the amount of exhaust gas being recirculated.

The EGR Vacuum Regulator (EVR) controls the vacuum applied to the EGR valve diaphragm.

NOTE: Other vacuum related components may be incorporated into the EGR system, depending on vehicle model and calibration.