FixVault

Test Procedures

  1. If using scan tool, go to step 2). Disconnect ECT sensor connector. Remove ECT sensor from intake manifold. Submerge temperature sensing portion of ECT sensor in hot water. Using DVOM, check resistance across ECT sensor terminals. See ECT SENSOR RESISTANCE SPECIFICATIONS  table. If resistance is not as specified, replace ECT sensor. If resistance is as specified, go to step 3).
    ECT SENSOR RESISTANCE SPECIFICATIONS

    Water Temperature Approximate Ohms
    32°F (0°C) 5800
    68°F (20°C) 2400
    104°F (40°C) 1100
    176°F (80°C) 300
  2. Turn ignition switch to ON or RUN position. Using a thermometer, check engine compartment ambient temperature. Using scan tool, read ECT SENSOR TEMPERATURE. Compare both readings. If readings are not about the same, replace ECT sensor. If readings are about the same go to next step.
  3. Disconnect ECT sensor connector. Using DVOM, check continuity between chassis ground and ECT sensor connector terminal No. 2. If continuity does not exist, repair wiring harness as necessary.
  4. Turn ignition switch to OFF position. With ECT sensor connector disconnected, disconnect ECM connector. Ground ECM connector terminal No. 83. Check continuity between chassis ground and ECT sensor connector terminal No. 1. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
  5. Test is complete. Intermittent problem may exist. Road test vehicle (if necessary) and attempt to duplicate conditions that caused original complaint. Recheck for DTCs. If no DTCs are displayed, go to INTERMITTENT DTCS  .