ECM EGR Solenoid

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

The ECM control of the EGR is based on the following inputs:

1. Coolant Temperature above 25~C
2. Throttle Position (TPS) - "OFF" idle
3. MAP