Code 32, EGR System Error (2 Of 3)

ECM operates a normally closed solenoid to regulate vacuum to EGR valve. When ECM provides a path to ground for EGR solenoid winding, solenoid opens, allowing vacuum to pass through to EGR valve. ECM monitors EGR effectiveness by shutting off vacuum to EGR valve during a steady cruise in excess of 50 MPH and monitoring change in MAP sensor vacuum signal. If vacuum signal change is not within a precalibrated window, Code 32 will be set.

1. 6)  Remaining tests check ability of EGR valve to interact with exhaust system. This system uses a positive backpressure EGR valve which will not hold vacuum until sufficient exhaust backpressure is at base of EGR valve.
2. 7)  EGR valve diaphragm should move when sufficient backpressure is at base of valve and when vacuum is being supplied to valve. Rapidly snapping throttle from idle should provide sufficient backpressure to close internal valve vacuum bleed. With valve bleed closed, jumpered vacuum supply can now lift valve off its seat.
3. 8)  Excessive exhaust backpressure from bent or restricted exhaust system components could provide enough backpressure at base of EGR valve to allow undesired EGR action at idle.
4. 9)  Plugged EGR exhaust passages can block exhaust backpressure at base of EGR valve. If this occurs, internal EGR valve bleed will remain open, preventing vacuum from operating valve.