| DTC P0138: | Secondary HO2S (Sensor 2) Circuit High Voltage |
| 1. | Turn the ignition switch ON (II). |
| 2. | Clear the DTC with the HDS. |
| 3. | Start the engine. Hold the engine speed at 3,000 rpm (min-1) without load (in Park or 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 1.25 V or more? YES - Go to 5. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM/ PCM.n |
| 5. | Turn the ignition switch OFF. |
| 6. | Remove the center console. |
| 7. | Disconnect the secondary HO2S (Sensor 2) 4P connector. |
| 8. | Connect secondary HO2S (Sensor 2) 4P connector terminals No. 1 and No. 2 with a jumper wire.
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| 9. | Turn the ignition switch ON (II). |
| 10. | Check the HO2S S2 in the DATA LIST with the HDS. Does the voltage stay at 1.25 V or more? YES - Go to 11. NO - Go to 20. |
| 11. | Turn the ignition switch OFF. |
| 12. | Remove the jumper wire from the secondary HO2S (Sensor 2) 4P connector. |
| 13. | Connect secondary HO2S (Sensor 2) 4P connector terminal No. 2 to body ground with a jumper wire.
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| 14. | Turn the ignition switch ON (II). |
| 15. | Check the HO2S S2 in the DATA LIST with the HDS. Does the voltage stay at 1.25 V or more? YES - Go to 16. NO - Repair open in the wire between the ECM/PCM (B33) and the secondary HO2S (Sensor 2), then go to 22. |
| 16. | Turn the ignition switch OFF. |
| 17. | Jump the SCS line with the HDS. |
| 18. | Disconnect ECM/PCM connector C (44P). |
| 19. | Check for continuity between ECM/PCM connector terminal C27 and body ground.
Is there continuity? YES - Go to 30. NO - Repair open in the wire between the ECM/PCM (C27) and the secondary HO2S (Sensor 2), then go to 22. |
| 20. | Turn the ignition switch OFF. |
| 21. | Replace the secondary HO2S (Sensor 2). |
| 22. | Reconnect all connectors. |
| 23. | Turn the ignition switch ON (II). |
| 24. | Reset the ECM/PCM with the HDS. |
| 25. | Do the ECM/PCM idle learn procedure. |
| 26. | Start the engine. Hold the engine speed at 3,000 rpm (min-1) without load (in Park or neutral) until the radiator fan comes on, then let it idle. |
| 27. | Test-drive under these conditions:
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| 28. | Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0138 is indicated, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Go to 29. |
| 29. | Monitor the OBD STATUS for DTC P0138 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete.n NO - If the screen indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM/PCM, then go to 1. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, go to 20 and recheck. |
| 30. | Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM. |
| 31. | Start the engine. Hold the engine speed at 3,000 rpm (min-1) without load (in Park or neutral) until the radiator fan comes on, then let it idle. |
| 32. | Test-drive under these conditions:
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| 33. | Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0138 is indicated, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM.n |