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Home >> Mazda >> 2003 >> MPV ES >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0116: Engine Coolant Temperature Circuit - Performance Problem >> Diagnostic Procedures
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Diagnostic Procedures

  1. Record freeze frame data. Check for service bulletins and on-line information. Repair as necessary. After repair, go to next step.
  2. Inspect Poor Connection Of ECT Sensor Connector -  Turn ignition off. Disconnect ECT sensor harness connector, located above starter. Check for damaged, loose or corroded terminals. If problem is not present, go to next step. If problem is present, repair as necessary. After repair, go to step  6.
  3. Inspect ECT Sensor -  Check resistance between ECT sensor terminals. See ENGINE COOLANT TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If ECT sensor is okay, go to next step. If sensor is not okay, go to step  5.
  4. Inspect Poor Connection Of PCM Connector -  Disconnect PCM 104-pin harness connector. Check for damaged, loose or corroded connection at terminal No. 38. If problem is present, repair as necessary. After repair, go to step  6. If problem is not present, go to step  6.
  5. Compare ECT PID Value -  Using scan tool, clear DTCs. Connect NEW ECT sensor into harness connector. Do not install NEW sensor in engine. Turn ignition on, engine off. Check and record ECT PID value. Turn ignition off. Install NEW sensor in engine. Start engine and wait 5 minutes. Check and record ECT PID value. If difference between first and second PID value is more than 42°F (5.6°C), go to step  7. If difference between first and second PID values is not as specified, go to next step.
  6. Verify Trouble Shooting Of DTC P0116 Completed -  Turn ignition off. Allow engine to cool for 6 hours. Reconnect all components. Using scan tool, clear DTC. See CLEARING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. Start engine and wait 5 minutes. Recheck DTCs. If DTC P0116 is present, replace PCM. After repair, go to next step. If DTC P0116 is not present, go to next step.
  7. Verify After Repair Procedure -  Using scan tool, perform After Repair Procedure. See AFTER REPAIR PROCEDURE . If no other DTCs are present, testing is complete. If any other DTC is present, go to applicable test and repair.
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