EGR Control Solenoid: Description and Operation

EGR System Check:

EGR System:

EGR And EVRV Solenoid:

OPERATION:

To regulate EGR flow, an ECM controlled Electronic Vacuum Regulator Valve (EVRV) solenoid is used in the vacuum line. The ECM uses information from the following sensors to regulate the solenoid:

- Coolant Temperature Sensor (CTS).
- Throttle Position Sensor (TPS).
- Park/Neutral (P/N) switch.
- Distributor (rpm signal).

The EGR vacuum control has an EVRV solenoid that uses Pulse Width Modulation (PWM). This means the ECM turns the solenoid ON and OFF many times a second and varies the amount of ON time (pulse width) to vary the amount of EGR.