K 3500 Truck 4WD V8-350 5.7L (1993)
Electronic Vacuum Regulator Valve (EVRV): Description and Operation
Port EGR Control Solenoid
EGR System
EGR And EVRV Solenoid
OPERATION
To regulate EGR flow, an control module controlled Electronic Vacuum Regulator Valve (EVRV) solenoid is used in the vacuum line. The
control module uses information from the following sensors to regulate the solenoid:
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Coolant Temperature Sensor (CTS).
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Throttle Position Sensor (TPS).
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Park/Neutral (P/N) switch.
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Distributor (RPM signal).
The EGR EVRV solenoid uses Pulse Width Modulation (PWM). This means the control module turns the solenoid ON and OFF many times a
second and varies the amount of ON time (pulse width) to vary the amount of vacuum to the EGR.