K 2500 Suburban 4WD V8-350 5.7L (1994)
Electronic Vacuum Regulator Valve (EVRV): Description and Operation
EGR System
Operation:
To regulate EGR flow a control module controlled solenoid is used in the vacuum line. This is a normally closed solenoid vacuum valve which is
opened when the control module completes the ground. The control module will energize the EGR solenoid (EGR ON) when the engine is warm
and above idle. There is little EGR flow at wide open throttle due to lack of engine vacuum.
