PCM Electronic Vacuum Regulator Solenoid (EVRV Solenoid)

To regulate EGR flow, the PCM operates a solenoid to control the EGR valve. This solenoid is normally closed. By providing a ground path, the PCM energizes the solenoid which then allows vacuum to pass to the EGR valve.

The EGR vacuum control has an EVRV solenoid that uses "pulse width modulation." This means the PCM turns the solenoid "ON" and "OFF" many times a second and varies the amount of "ON" time ("pulse width") to vary the amount of exhaust gas flow.