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Diagnosis & Repair (Using OBD-II Scan Tool)

  1. Disconnect EGR temperature sensor. EGR temperature sensor is mounted in intake air chamber. Using ohmmeter, measure resistance between sensor terminals. If resistance is 600,000 ohms or less, go to next step. If resistance is more than 600,000 ohms, check sensor. See SYSTEM/COMPONENT TESTS - 2.7L . Replace as necessary.
  2. Turn ignition on. Using DVOM, measure voltage between sensor wiring harness connector terminals. If voltage is 4.5-5.5 volts, go to step 4). If voltage is not 4.5-5.5 volts, go to next step.
  3. Access ECM behind passenger's side kick panel. Turn ignition on. On A/T models, measure voltage 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, measure voltage between terminals No. 9 (Brown/Black wire) and No. 3 (Green/White wire) at ECM E6 connector. On all models, if voltage is 4.5-5.5 volts, repair open circuit in wiring harness between EGR temperature sensor and ECM. See appropriate wiring diagram in WIRING DIAGRAMS - 2.7L article. If voltage is not 4.5-5.5 volts, replace ECM and retest.
  4. Check all EGR system vacuum hoses. Replace vacuum hoses as necessary. Access ECM behind passenger's side kick panel. Ensure ignition is off. pressure to EGR VSV port "E". See Figure. Air from port "E" should flow from port "F". Disconnect jumper wire. Air from port "E" should not flow from port "F". If EGR VSV operates as specified, go to step 9). If VSV does not operate as specified, go to next step.
  5. On all models, with jumper wire connected EGR Vacuum Switching Valve (VSV) is on. Apply air pressure to EGR VSV port "E". See Figure. Air from port "E" should flow from port "F". Disconnect jumper wire. Air from port "E" should not flow from port "F". If EGR VSV operates as specified, go to step 9). If VSV does not operate as specified, go to next step.
  6. Turn ignition off. Remove EGR VSV. Using ohmmeter, measure resistance between valve terminals. Resistance should be 33-39 ohms at 68°F (20°C). Check for continuity between each terminal and body of EGR VSV. If continuity exists, replace EGR VSV. If continuity does not exist, go to next step.
  7. Check EGR VSV operation. Apply battery voltage to EGR VSV terminals. Apply air pressure to EGR VSV port "E". See Figure. 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, go to next step.
  8. Check for open circuit in wiring harness between engine compartment fuse block and ECM. See appropriate wiring diagram in WIRING DIAGRAMS - 2.7L article. Repair wiring as necessary.
  9. Check EGR vacuum modulator. See SYSTEM/COMPONENT TESTS - 2.7L article. Replace EGR vacuum modulator as necessary. Check EGR valve. See SYSTEM/COMPONENT TESTS - 2.7L article. Replace EGR valve as necessary.
  10. Disconnect EGR temperature sensor connector. Start engine. Ensure engine is at normal operating temperature. Run engine at 4000 RPM for 3 minutes and measure resistance between EGR temperature sensor terminals. If resistance is 4300 ohms or less, replace ECM and retest. If resistance is more than 4300 ohms, replace EGR temperature sensor.
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