Code 32, EGR Circuit
The EGR vacuum control has an ECM controlled solenoid that pulses manifold vacuum to the EGR valve. The solenoid is always de-energized in Park, Neutral and at idle. The ECM monitors EGR effectiveness by de-energizing the EGR control solenoid, shutting off vacuum to the EGR valve. With EGR valve closed, block learn should be greater that it was during EGR operation.
An EGR valve that is stuck open will cause a rough idle. A plugged EGR solenoid vent could cause the EGR valve to remain open or to close slowly. An inoperative check valve in the ported signal line will result in faulty EGR system operation.