Diesel Data: Automotive Repair

EGR Control Solenoid: Description and Operation

EGR Solenoid Vacuum (SV) Valve (California Emissions Only)

The Exhaust Gas Recirculation (EGR) system is controlled by the ECM through an EGR Electronic Vacuum Regulating Solenoid Valve (EVRV) and backpressure transducer. Vacuum is allowed to the EGR valve at acceleration and shut "OFF" upon deceleration or constant engine speed.

Under any one of the following conditions, the ECM closes the vacuum passage of the EGR EVRV. in this state, as vacuum is not transmitted to the EGR valve, it remains closed.

^ When engine coolant temperature is low.
^ When throttle valve is at idle position.
^ When engine is running under high load.

Other than the above, EGR valve opens and closes in accordance with EGR backpressure transducer operation.