Bravada V6-262 4.3L VIN Z (1991)
EGR Electronic Vacuum Regulator Solenoid: Description and 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:
1. Coolant Temperature above 25~C
2. Throttle Position (TPS) - "OFF" idle
3. MAP
The EGR vacuum control has an EVRV solenoid that uses "pulse width modulation." 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.
