Pickup 2WD L4-2254cc 2.3L SOHC (4ZD1) MFI (1994)
EGR Vacuum Switching Valve: Description and Operation
EGR Duty Solenoid And Vacuum Switching Valve
EGR system control and optimum EGR volume are determined by the ECM based on three main signals:
1.
Engine RPM
2.
Intake air volume
3.
Coolant temperature
To operate the system, the ECM controls a duty solenoid which in turn regulates vacuum to the EGR valve. Also incorporated into the system is an
ECM controlled vacuum switching valve for EGR cut under specified conditions.