EGR Modulator (BACKPRESSURE Transducer)
- For EGR modulator location, see appropriate vacuum diagram in VACUUM DIAGRAMS article. Remove upper cap from modulator. Remove filter and clean with compressed air. Install upper cap. Remove EGR modulator.
- Plug one upper vacuum hose port while applying LOW PRESSURE air to opposite vacuum hose port. Air should flow freely through filter housing.
- Connect hand-held vacuum pump to one upper vacuum hose port. Connect vacuum gauge to opposite vacuum hose port. Apply LOW PRESSURE air to bottom port while applying vacuum with vacuum pump. Vacuum should be indicated on gauge. When low pressure air application stops at bottom port, vacuum gauge indicator should return to zero. Replace EGR modulator if operation is not as specified.