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. Reading and Clearing Diagnostic Trouble Codes
- Information marked with an asterisk (*) applies to the front bank (Bank 2).
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 HO2S S2 in the DATA LIST with the HDS.
Does the voltage stay at 1.25 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).
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).
9. Check HO2S S2 in the DATA LIST with the HDS.
Does the voltage stay at 1.25 V or more?
YES - Go to step 10.
NO - Go to step 19.
10. Turn the ignition switch to LOCK (0).
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).
14. Check HO2S S2 in the DATA LIST with the HDS.
Does the voltage stay at 1.25 V or more?
YES - Go to step 15.
NO - Repair open in the wire between the PCM (C12) and secondary HO2S (Sensor 2), then go to step 21.
15. Turn the ignition switch to LOCK (0).
16. Jump the SCS line with the HDS.
17. Disconnect PCM connector B (24P).
18. Check for continuity between PCM connector terminal B9 (B18)* and body ground.
Is there continuity?
YES - Go to step 29.
NO - Repair open in the wire between the PCM (B9 (B18)*) and secondary HO2S (Sensor 2), then go to step 21.
19. Turn the ignition switch to LOCK (0).
20. Replace secondary HO2S (Sensor 2). Secondary HO2S Replacement
21. Reconnect all connectors.
22. Turn the ignition switch to ON (II).
23. Reset the PCM with the HDS.
24. Do the PCM idle learn procedure. PCM Idle Learn Procedure
25. 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.
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
- Drive 1 minute 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 screen 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 screen indicates FAILED, check for poor connections or loose terminals at secondary HO2S (Sensor 2) and the PCM, 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 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. Reading and Clearing Diagnostic Trouble Codes
31. 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.
32. 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
- Drive 1 minute 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, Reading and Clearing Diagnostic Trouble Codes then go to step 31. If the PCM was substituted, go to step 1.
NO - Go to step 33.
34. Monitor the OBD STATUS for DTC P0138 and/or P0158* in the DTCs MENU with the HDS.
Does the screen 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 screen 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, Reading and Clearing Diagnostic Trouble Codes then go to step 31. If the PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, go to step 31.