Caprice Wagon V8-350 5.7L (1994)
EGR Electronic Vacuum Regulator Solenoid: Description and Operation
EGR Control Solenoid Circuit.
PURPOSE
The Exhaust Gas Recirculation (EGR) vacuum control has a vacuum control solenoid that uses "Pulse Width Modulation" (PWM). This means
that the PCM turns the solenoid "OFF" and "ON" many times a second and varies the amount of "ON" time (pulse width) to vary the amount
ported manifold vacuum to the EGR valve.
OPERATION
The PWM is calculated by the PCM based on information from the coolant temperature, air flow and engine rpm. There should be no EGR
function when in park or neutral, TPS input below a specified value, or TPS indicating Wide Open Throttle (WOT).
LOCATION
The EGR solenoid is mounted to the left side of the intake manifold.