Plugged Exhaust Passage

With EGR valve removed, plug intake manifold side passage using a suitable plug. Start engine and listen for exhaust noise. If no exhaust gas escapes from open EGR port, exhaust passage is plugged.

1. 2)
   
   Using Tech 1 tester, EGR solenoid should energize and allow vacuum to be applied to gauge. Vacuum at gauge may or may not slowly bleed off; however, gauge is able to read amount of vacuum being applied.
2. 3)
   
   Upon exiting field service mode, gauge vacuum should bleed off through a vent in solenoid. Pump gauge vacuum may or may not bleed off; this does not indicate a problem.
3. 4)
   
   This test determines if electrical control part of system is at fault or if connector or solenoid is at fault.
4. 5)
   
   EGR solenoid, ECM and vacuum supply are okay.
5. 6)
   
   Remaining tests check ability of EGR valve to interact with exhaust system. This system uses a negative backpressure EGR valve which will hold vacuum with engine off.
6. 7)
   
   EGR valve diaphragm should move when sufficient exhaust pressure is present at base of EGR valve and when vacuum is being supplied to valve. Rapidly snapping throttle from idle should provide enough backpressure to base of valve which should close valve's internal bleed. With this internal valve closed, valve can now be lifted off it's seat. Valve pintle must move at the appropriate time.