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EGR Vacuum Modulator Test

  1. EGR vacuum modulator may be a 2-port or 3-port depending on application. On 2 port models, disconnect hoses from vacuum modulator. Plug one end of vacuum hose connection on EGR vacuum modulator.
  2. Apply air pressure through remaining port. Air should pass freely through air filter side of modulator. On 3-port models, disconnect all hoses. Block ports "P" and "R". Apply air pressure to port "Q". See Fig 1. Air should pass through the air filter side of modulator freely.
    Fig 1: Testing 3-Port Vacuum Modulator
    G118998Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. On all models, operate engine at 2500 RPM. Repeat previous test procedure in steps 1) and 2). Strong resistance of airflow should be felt. Replace EGR vacuum modulator if resistance is not felt. Reconnect vacuum hoses to proper locations
EGR VACUUM MODULATOR SPECIFICATIONS

Application Engine RPM
3-Port Type
Land Cruiser 2500