EGR Backpressure Transducer: Testing and Inspection

Vacuum Modulator:

1. Check the filter in top of modulator for contamination or damage.

2. Using compressed air clean the filter.

NOTE: Install the filter with the coarser surface facing the atmospheric side (outward).

3. Disconnect vacuum hoses from ports P, Q and R of the vacuum modulator.

Vacuum Modulator Test (engine Stopped):

4. Block ports P and R with fingers.

5. Blow air into port Q and ensure air passes through to the air filter side freely.

6. Start engine maintaining 2,500 rpm.

Vacuum Modulator Test (2500 Rpm):

7. Repeat steps 3 - 5. Ensure there is a strong resistance to air flow.

8. If vacuum modulator does not function as described above, replace modulator.

9. Reconnect vacuum hoses to their proper position.