LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 1996 >> Monte Carlo LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 3.1L Engine >> Diagnostic Trouble Codes >> DTC P0125 - ECT Excessive Time To Reach Closed Loop >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) System Check. After performing OBD system check, go to next step.
  2. Allow engine to cool to ambient temperature. Start engine and allow it to idle. Using scan tool, monitor ENG COOL TEMP display for 9 minutes. If value increases to greater than 70°F (21°C), see DIAGNOSTIC AIDS. If value does not increase to greater than 70°F (21°C), go to next step.
  3. If any ECT sensor DTCs are set, diagnose DTCs as necessary. If no other DTCs are set, go to next step.
  4. Allow engine to cool. Turn ignition on. Observe cooling fans operation. If fans are off, go to next step. If fans are on, repair cooling fans system as necessary.
  5. Check cooling system coolant level. If fluid level is low, go to step 9). If fluid level is okay, go to next step.
  6. Check thermostat operation. If thermostat is operating properly, go to next step. If thermostat is not operating properly, go to step 9).
  7. Using scan tool, compare ENG COOL TEMP display with actual coolant temperature measured with a thermometer. If temperature values are close, go to step 9). If temperature values are not close, go to next step.
  8. Check for high resistance is ECT sensor wiring harness. Also, check for poor connections at ECT sensor connector and PCM connector. If a problem is found, go to step 10). If wiring is okay, go to step 11).
  9. Check cooling system and repair as necessary. After repair is completed, go to step 12).
  10. Repair faulty wiring or terminals as necessary. After repair is completed, go to step 12).
  11. Replace ECT sensor. After repair is completed, go to next step.
  12. Allow engine to cool completely. Using scan tool, select CLEAR INFO or CLEAR DTCS function to clear DTCs. Start engine and allow it to idle. Monitor ENG COOL TEMP display for 9 minutes. If value increases to greater than 70°F (21°C), repair is complete. If value does not increase to greater than 70°F (21°C), repeat step 2).
scientia non olet · About LEMON Manuals