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Home >> Chevrolet >> 2001 >> Prizm Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics - 1.8L >> Diagnostic Tests >> DTC P0116: ECT Sensor Circuit Performance >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform powertrain diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check, go to next step.
  2. Using scan tool, check if DTC P0115 is set. If DTC P0115 is set, diagnose DTC. See DTC P0115 . If DTC P0115 is not set, go to next step.
  3. Measure actual engine coolant temperature. Using scan tool, monitor ECT sensor parameter. If scan tool display value is about actual engine coolant temperature, go to step  11. If scan tool display value is not about actual engine coolant temperature, go to next step.
  4. Disconnect ECT sensor harness connector. Using scan tool, monitor ECT sensor parameter. If ECT sensor parameter is -40°F (-40°C), go to next step. If ECT sensor parameter is not -40°F (-40°C), go to step  8.
  5. Using a fused jumper wire, jumper ECT sensor harness connector terminals. Using scan tool, monitor ECT sensor parameter. If ECT sensor parameter is 284°F (140°C), go to step  13. If ECT sensor parameter is not 284°F (140°C), go to next step.
  6. Using a fused jumper wire, jumper ECT sensor harness connector terminal No. 2 (White wire). Using scan tool, monitor ECT sensor parameter. If ECT sensor parameter is 284°F (140°C), go to next step. If ECT sensor parameter is not 284°F (140°C), go to step  8.
  7. Turn ignition off. Repair open or high resistance in Brown wire between ECT sensor harness connector terminal No. 1 and PCM harness connector C2 terminal No. 18 for 4-speed A/T or terminal No. 9 for except 4-speed A/T. See Figure or Figure . After repairs, go to step  14. If circuit is okay, go to step  9.
  8. Turn ignition off. Disconnect PCM harness connector C2. Check for short or high resistance in White wire between ECT sensor harness connector terminal No. 2 and PCM harness connector C2 terminal No. 14 for 4-speed A/T or No. 4 for except 4-speed A/T. See Figure or Figure . Repair as necessary. After repairs, go to step  14. If circuit is okay, go to next step.
  9. Check for a faulty connection at PCM and ECT harness connectors. Repair as necessary. After repairs, go to step  14. If connections are okay, go to next step.
  10. Replace PCM. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After replacing PCM, go to step  14.
  11. Inspect engine cooling system for a faulty thermostat, low coolant level, incorrect coolant, or faulty cooling system operation. Repair as necessary. After repairs, go to step  14. If cooling system is okay, go to next step.
  12. Using scan tool, clear DTC information and place vehicle into check mode. Operate vehicle within FREEZE FRAME conditions to set this DTC. If DTC resets, go to next step. If DTC does not reset, see DIAGNOSTIC AIDS .
  13. Replace ECT sensor. After replacing sensor, go to next step.
  14. Turn ignition on, with engine off. Using scan tool, clear DTC information. Road test vehicle within conditions for running DTC. See CODE ENABLE CRITERIA . Check for DTCs. If no DTCs are stored, repair is complete. If any DTCs are stored, diagnose affected DTCs.
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