DTC Troubleshooting

DTC Troubleshooting: P2185

DTC P2185: ECT Sensor 2 Circuit High Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Initial Inspection and Diagnostic Overview

1. Turn the ignition switch to ON (II).

2. Check ECT SENSOR 2 in the DATA LIST with the HDS.

Is about -40 °F (-40 °C) or less, or 4.92 V or more indicated?
YES - Go to step 3.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 2 and the ECM.


3. Turn the ignition switch to LOCK (0).

4. Disconnect the ECT sensor 2 2P connector.

5. Connect ECT sensor 2 2P connector terminals No. 1 and No. 2 with a jumper wire.

6. Turn the ignition switch to ON (II).

7. Check ECT SENSOR 2 in the DATA LIST with the HDS.

Is about -40 °F (-40 °C) or less, or 4.92 V or more indicated?
YES - Go to step 8.

NO - Go to step 18.






8. Turn the ignition switch to LOCK (0).

9. Remove the jumper wire from the ECT sensor 2 2P connector.

10. Turn the ignition switch to ON (II).

11. Measure the voltage between ECT sensor 2 2P connector terminal No. 1 and body ground.

Is there about 5 V?
YES - Go to step 12.

NO - Go to step 17.






12. Turn the ignition switch to LOCK (0).

13. Jump the SCS line with the HDS.

14. Disconnect ECM connector E (31P).

15. Connect ECT sensor 2 2P connector terminal No. 2 to body ground with a jumper wire.






16. Check for continuity between ECM connector terminal E4 and body ground.

Is there continuity?
YES - Go to step 26.

NO - Repair open in the wire between the ECM (E4) and ECT sensor 2, then go to step 20.






17. Measure the voltage between ECM connector terminal E1 and body ground.

Is there about 5 V?
YES - Repair open in the wire between the ECM (E1) and ECT sensor 2, then go to step 20.

NO - Go to step 25.






18. Turn the ignition switch to LOCK (0).

19. Replace ECT sensor 2. ECT Sensor 2 Replacement

20. Reconnect all connectors.

21. Turn the ignition switch to ON (II).

22. Reset the ECM with the HDS.

23. Do the ECM idle learn procedure. ECM Idle Learn Procedure

24. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2185 indicated?
YES - Check for poor connections or loose terminals at ECT sensor 2 and the ECM, then go to step 1.

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


25. Turn the ignition switch to LOCK (0).

26. Reconnect all connectors.

27. Update the ECM if it does not have the latest software, ECM Update or substitute a known-good ECM. Initial Inspection and Diagnostic Overview

28. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2185 indicated?
YES - Check for poor connections or loose terminals at ECT sensor 2 and the ECM. If the ECM was updated, substitute a known-good ECM, Initial Inspection and Diagnostic Overview then recheck. If the ECM was substituted, go to step 1.

NO - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. Service and Repair If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.