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Diagnosis & Repair (Using Toyota Scan Tool)

  1. Connect scan tool. See Figure. Turn ignition on. Read EGR gas temperature. If temperature is 50°F (10°C) or more, go to step 6). If temperature is less than 50°F (10°C), go to next step.
    NOTE: If EGR gas temperature is 37.6°F (3.1°C), an open exist in EGR temperature sensor circuit.
  2. Disconnect EGR temperature sensor connector. Sensor is mounted in intake air chamber. Connect a jumper wire between sensor wiring harness connector terminals.
  3. If EGR temperature displayed is not 318.7°F (159.3°C), go to next step. If temperature displayed is 318.7°F (159.3°C), check sensor connectors and terminals. Repair as necessary. If connectors are okay, replace sensor and retest.
  4. Remove jumper wire. Turn ignition off. Access ECM behind passenger's side kick panel. On A/T models, connect jumper wire between terminals No. 9 (Brown/Black wire) and No. 14 (Green/White wire) at ECM E6 connector. See Figure or Figure. On M/T models, connect a jumper wire between terminals No. 9 (Brown/Black wire) and No. 3 (Green/White wire) at ECM E6 connector. On all models, turn ignition on.
  5. If EGR temperature displayed is 318.7°F (159.3°C), locate and repair open circuit in wiring harness between ECM and EGR temperature sensor. If temperature displayed is not 318.7°F (159.3°C), replace ECM and retest.
  6. Check vacuum hoses. See appropriate illustration in VACUUM DIAGRAMS - 2.7L article. Replace vacuum hoses as necessary. If all hoses are okay, check EGR VSV. Using scan tool, select ACTIVE TEST mode. Check operation of EGR VSV when activated by scan tool. EGR VSV is located under air intake chamber.
  7. Apply air pressure to EGR VSV port "E". See Fig 1. With EGR system off, air from port "E" should flow from port "F". With EGR system on, air from port "E" should not flow from port "F". If EGR VSV operates as specified, go to step 10). If EGR VSV does not operate as specified, go to next step.
  8. Remove EGR VSV. Using ohmmeter, measure resistance between EGR VSV terminals. Resistance should be 33-39 ohms at 68°F (20°C). Measure resistance between each terminal and body of EGR VSV. Resistance should be infinite. If resistance is not as specified, replace EGR VSV. If resistance is as specified, go to next step.
  9. Check EGR VSV operation. Apply battery voltage to EGR VSV terminals. Apply air pressure to EGR VSV port "E". See Fig 1. Air from port "E" should flow from port "F". Remove battery voltage from EGR VSV terminals. Air from port "E" should not flow from port "F". Replace EGR VSV as necessary. If EGR VSV operates as specified, check for short circuit in wiring harness between EGR VSV and ECM. See appropriate wiring diagram in WIRING DIAGRAMS - 2.7L article. Repair wiring as necessary.
  10. Check EGR vacuum modulator. See SYSTEM/COMPONENT TESTS - 2.7L article. Replace EGR vacuum modulator as necessary. If EGR vacuum modulator is okay, check EGR valve. See SYSTEM/COMPONENT TESTS - 2.7L article. Replace EGR valve as necessary. If components are okay, go to next step.
  11. Ensure all components are connected. Check EGR temperature sensor. Start and run engine. Using scan tool, select ACTIVE TEST mode (EGR system ON). Run engine at 4000 RPM for 3 minutes. Monitor EGR gas temperature. If temperature is 284°F (140°C) or more, replace ECM and retest. If temperature is less than 284°F (140°C), replace EGR temperature sensor.
Fig 1: Identifying EGR Vacuum Switching Valve (EVAP VSV Is Similar)
G96B10182Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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