DTC Troubleshooting
DTC Troubleshooting: P0138, P0158
DTC P0138:
Rear Secondary HO2S (Bank 1, Sensor 2) Circuit High Voltage
DTC P0158:
Front Secondary HO2S (Bank 2, 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.
- Information marked with an asterisk (*) applies to the front bank (Bank 2).
1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
2. Clear the DTC with the HDS.
3. Start the engine, and let it idle without load (in P or N) until the radiator fan comes on.
4. Check the HO2S B1 S2 OUTPUT VOLTAGE and/or HO2S B2 S2 OUTPUT VOLTAGE* in the DATA LIST with the HDS.
Does the voltage stay at 1.27 V or more?
YES -
Go to step 5.
NO -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at secondary HO2S (Sensor 2) and the PCM.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Disconnect the secondary HO2S (Sensor 2) 4P connector.
7. Connect secondary HO2S (Sensor 2) 4P connector terminals No. 1 and No. 2 with a jumper wire.
8. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
9. Check the HO2S B1 S2 OUTPUT VOLTAGE and/or HO2S B2 S2 OUTPUT VOLTAGE* in the DATA LIST with the HDS.
Does the voltage stay at 1.27 V or more?
YES -
Go to step 10.
NO -
Go to step 19.
10. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
11. Remove the jumper wire from the secondary HO2S (Sensor 2) 4P connector.
12. Connect secondary HO2S (Sensor 2) 4P connector terminal No. 1 to body ground with a jumper wire.
13. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
14. Check the HO2S B1 S2 OUTPUT VOLTAGE and/or HO2S B2 S2 OUTPUT VOLTAGE* in the DATA LIST with the HDS.
Does the voltage stay at 1.27 V or more?
YES -
Go to step 15.
NO -
Repair an open in the wire between the PCM (C23 (C36)*) and secondary HO2S (Sensor 2), then go to step 21.
15. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
16. Jump the SCS line with the HDS.
17. Disconnect PCM connector B (49P).
18. With the jumper wire still connected between secondary HO2S terminal No. 1 and body ground, check for continuity between PCM connector terminal B25 (B16)* and body ground.
Is there continuity?
YES -
Go to step 29.
NO -
Repair an open in the wire between the PCM (B25 (B16)*) and secondary HO2S (Sensor 2), then go to step 21.
19. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
20. Replace secondary HO2S (Sensor 2) Secondary HO2S Replacement.
21. Reconnect all connectors.
22. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
23. Reset the PCM with the HDS.
24. Do the PCM idle learn procedure PCM Idle Learn Procedure.
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 at 1,500-3,000 rpm
- Maintain a steady speed for 5 seconds or more
27. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0138 and/or P0158* indicated?
YES -
Check for poor connections or loose terminals at secondary HO2S (Sensor 2) and the PCM, then go to step 1.
NO -
Go to step 28.
28. Monitor the OBD STATUS for DTC P0138 and/or P0158* 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 27, go to the indicated DTC's troubleshooting.
NO -
If the HDS indicates FAILED, check for poor connections or loose terminals at 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 25.
29. Reconnect all connectors.
30. Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM.
31. Start the engine, and let it idle without load (in P or N) until the radiator fan comes on.
32. Test-drive under these conditions:
- Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
- Transmission in D
- Engine speed at 1,500-3,000 rpm
- Maintain a steady speed for 5 seconds or more
33. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0138 and/or P0158* indicated?
YES -
Check for poor connections or loose terminals at secondary HO2S (Sensor 2) and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 31. If the PCM was substituted, go to step 1.
NO -
Go to step 34.
34. Monitor the OBD STATUS for DTC P0138 and/or P0158* 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 33, go to the indicated DTC's troubleshooting.
NO -
If the HDS indicates FAILED, check for poor connections or loose terminals at secondary HO2S (Sensor 2) and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 31. 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 31.