Century V6-260 4.3L DSL (1984)
EGR Vacuum Solenoid Valve: Testing and Inspection
EGR Solenoid Check
Fig. 028 - WIRING DIAGRAM for EGR Solenoid Check. VIN T, VIN V
EGR SOLENOID CHECK
The EGR solenoid controls vacuum to the EGR valve. The signal from the ECM is Pulse Width Modulated (PWM), which changes the cycle ("ON"
time) from 0% to 100%. As the EGR solenoid cycles, vacuum to the EGR valve is controlled. The solenoid operates on 12V, supplied by the ignition to
the solenoid. The ground is completed by the ECM to turn the solenoid "ON", allowing vacuum to the EGR valve. A vacuum error will set a CEL, and
could be the result of a faulty EGR solenoid. When a vacuum error is sensed by the ECM, EGR is turned "OFF". It takes approximately 10 seconds for
the ECM to sense a vacuum error, and the CEL will not go "OFF" until the key is turned "OFF".
