EGR Backpressure Transducer: Testing and Inspection

EGR VACUUM MODULATOR INSPECTION

Inspect EGR vacuum modulator operation.
(a) Disconnect the vacuum hoses from ports P, Q and R of the EGR vacuum modulator.





(b) Block ports P and R with your finger.
(c) Blow air into port Q, and check that the air passes through to the air filter side freely.





(d) Start the engine, and maintain speed at 3,000 rpm.
(e) Repeat the above test. Check that there is a strong resistance to air flow.
If operation is not as specified, replace the EGR vacuum modulator.
(f) Reconnect the vacuum hoses to the proper locations.