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Home >> Chevrolet >> 2001 >> Tracker 2D Utility, RWD, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics >> Diagnostic Tests >> DTC P0125: ECT Excessive Time To Enter Closed Loop >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check, go to next step.
  2. Turn ignition off. Allow engine to cool to ambient air temperature. Turn ignition on, with engine off. Compare ECT sensor parameter to IAT sensor parameter on scan tool. If both parameters are within 2-3° of each other, go to next step. If both parameters are not within 2-3° of each other, go to step  6 .
  3. Start engine and immediately observe ECT sensor parameter on scan tool. Continue observing ECT for 10 minutes with engine at idle. If ECT indicated on scan tool increases to greater than 68°F (20°C) within 10 minutes, go to step  5 . If ECT indicated on scan tool does not increase to greater than 68°F (20°C) within 10 minutes, go to next step.
  4. Retrieve DTCs. If any ECT related DTCs are set, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS  . If no ECT related DTCs are set, go to step  8 .
  5. Fault is not present. Check for any other DTCs. Diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS  . If no other DTCs are set, see DIAGNOSTIC AIDS  .
  6. Turn ignition off. Check ECT sensor resistance. Compare ECT sensor resistance with resistance values table. See ENGINE SENSORS & SWITCHES in appropriate SYSTEM & COMPONENT TESTING article. If ECT sensor resistance is as specified, go to next step. If ECT sensor resistance is not as specified, go to step  9 .
  7. Check for high resistance in ECT sensor circuits. Check for poor connections at PCM and ECT sensor. Repair as necessary. After repairs, go to step  11 . If circuit and connections are okay, go to step  10 .
  8. Check coolant level or for proper operation of cooling system and thermostat. Repair as necessary. After repairs, go to step  11 .
  9. Replace ECT sensor. After replacing sensor, go to step  11 .
  10. Replace PCM. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After replacing PCM, go to next step.
  11. Turn ignition on, with engine off. Using scan tool, clear DTCs. Turn ignition off for 30 seconds. Start engine. Operate vehicle within the conditions for running the DTC or until the DTC P0125 diagnostic has run. See CODE ENABLE CRITERIA  . If DTC runs and passes, go to next step. If DTC resets, go to step  2 .
  12. Using scan tool, observe the stored information and Capture Info. If scan tool displays any undiagnosed DTCs, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS  . If no DTCs are displayed, system is okay.
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