DTC Troubleshooting

DTC Troubleshooting: P0137

DTC P0137: Secondary HO2S (Sensor 2) Circuit Low 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

- Information marked with an asterisk (*) applies to '07-09 models.

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

2. Clear the DTC with the HDS.

3. Start the engine. Hold the engine speed at 3,000 rpm without load (in neutral) until the radiator fan comes on, then let it idle.

4. Check the HO2S S2 in the DATA LIST with the HDS.

Does the voltage stay at 0.29 (0.05)* V or less?
YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM.


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

6. Remove the center console. Center Console Removal/Installation

7. Disconnect the secondary HO2S (Sensor 2) 4P connector.

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

9. Check the HO2S S2 in the DATA LIST with the HDS.

Does the voltage stay at 0.29 (0.05)* V or less?
YES - Go to step 10.

NO - Go to step 14.


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

11. Jump the SCS line with the HDS.

12. Disconnect ECM connector C (44P).

13. Check for continuity between secondary HO2S (Sensor 2) 4P connector terminal No. 2 and body ground.

Is there continuity?
YES - Repair short in the wire between the ECM (C27) and the secondary HO2S (Sensor 2), then go to step 16.

NO - Go to step 24.






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

15. Replace the secondary HO2S (Sensor 2). Secondary HO2S Replacement

16. Reconnect all connectors.

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

18. Reset the ECM with the HDS.

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

20. Start the engine, and let it idle without load (in neutral) until the radiator fan comes on.

21. Test-drive under these conditions:
- Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)

- Transmission in 4th

- Engine speed between 1,500-3,000 rpm

- Drive about 1 minute or more

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

Is DTC P0137 indicated?
YES - Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM, then go to step 1.

NO - Go to step 23.


23. Monitor the OBD STATUS for DTC P0137 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 22, go to the indicated DTC's troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM, then go to step 1. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, go to step 20.


24. Reconnect all connectors.

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

26. Start the engine, and let it idle without load (in neutral) until the radiator fan comes on.

27. Test-drive under these conditions:
- Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)

- Transmission in 4th

- Engine speed between 1,500-3,000 rpm

- Drive 1 minute or more

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

Is DTC P0137 indicated?
YES - Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM. If the ECM was updated, substitute a known-good ECM, Initial Inspection and Diagnostic Overview then go to step 26. If the ECM was substituted, go to step 1.

NO - Go to step 29.


29. Monitor the OBD STATUS for DTC P0137 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?
YES - 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 were indicated in step 28, go to the indicated DTC's troubleshooting.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM. If the ECM was updated, substitute a known-good ECM, Initial Inspection and Diagnostic Overview then go to step 26. If the ECM was substituted, go to step 1. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, go to step 26.