DTC Troubleshooting
DTC Troubleshooting: P0137 (63)
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.
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 P or N) 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 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 PCM.
5. Turn the ignition switch to LOCK (0).
6. Disconnect the secondary HO2S (Sensor 2) 4P connector.
7. Turn the ignition switch to ON (II).
8. Check the HO2S S2 in the DATA LIST with the HDS.
Does the voltage stay at 0.29 V or less?
YES -
Go to step 9.
NO -
Go to step 13.
9. Turn the ignition switch to LOCK (0).
10. Jump the SCS line with the HDS.
11. Disconnect PCM connector C (44P).
12. Check for continuity between secondary HO2S (Sensor 2) 4P connector terminal No. 1 and body ground.
Is there continuity?
YES -
Repair a short in the wire between the PCM (C27) and the secondary HO2S (Sensor 2), then go to step 15.
NO -
Go to step 23.
13. Turn the ignition switch to LOCK (0).
14. Replace the secondary HO2S (Sensor 2) Secondary HO2S Replacement.
15. Reconnect all connectors.
16. Turn the ignition switch to ON (II).
17. Reset the PCM with the HDS.
18. Do the PCM idle learn procedure PCM Idle Learn Procedure.
19. Start the engine, and let it idle without load (in P or N) until the radiator fan comes on.
20. Test-drive under these conditions:
- Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
- Transmission in D
- Engine speed between 1,500-3,000 rpm
- Maintain a steady speed for 1 minute or more
21. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0137 indicated?
YES -
Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1.
NO -
Go to step 22.
22. Monitor the OBD STATUS for DTC P0137 in the DTCs MENU with the HDS.
Does the HDS indicate PASSED?
YES -
Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 21, go to the indicated DTC's troubleshooting.
NO -
If the HDS indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1. If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 19.
23. Reconnect all connectors.
24. Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM.
25. Start the engine, and let it idle without load (in P or N) until the radiator fan comes on.
26. Test-drive under these conditions:
- Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
- Transmission in D
- Engine speed between 1,500-3,000 rpm
- Maintain a steady speed for 1 minute or more
27. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0137 indicated?
YES -
Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 25. If the PCM was substituted, go to step 1.
NO -
Go to step 28.
28. Monitor the OBD STATUS for DTC P0137 in the DTCs MENU with the HDS.
Does the HDS indicate PASSED?
YES -
If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. If any other Pending or Confirmed DTCs were indicated in step 27, go to the indicated DTC's troubleshooting.
NO -
If the HDS indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 25. If the PCM was substituted, go to step 1. If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 25.