| DTC P0141: | Secondary HO2S (Sensor 2) Heater Circuit Malfunction |
| 1. | Turn the ignition switch ON (II). |
| 2. | Clear the DTC with the HDS. |
| 3. | Start the engine. |
| 4. | Check for Temporary DTCs or DTCs with the HDS. Is DTC P0141 indicated? 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. | Check the No. 3 ALTERNATOR (10 A) fuse in the under-dash fuse/relay box. Is the fuse OK? YES - Go to 7. NO - Repair short in the wire between the secondary HO2S (Sensor 2) and the No. 3 ALTERNATOR (10 A) fuse. Also replace the No. 3 ALTERNATOR (10 A) fuse, then go to 22. |
| 7. | Disconnect the secondary HO2S (Sensor 2) 4P connector. |
| 8. | At the secondary HO2S (Sensor 2) side, measure resistance between secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4.
Is there 5.4-6.6 W at room temperature? YES - Go to 9. NO - Go to 21. |
| 9. | At the secondary HO2S (Sensor 2) side, check for continuity between body ground and secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4 individually.
Is there continuity? YES - Go to 21. NO - Go to 10. |
| 10. | Turn the ignition switch ON (II). |
| 11. | Measure voltage between secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4.
Is there battery voltage? YES - Go to 12. NO - Go to 16. |
| 12. | Turn the ignition switch OFF. |
| 13. | Jump the SCS line with the HDS. |
| 14. | Disconnect ECM/PCM connector B (44P). |
| 15. | Check for continuity between ECM/PCM connector terminal B4 and body ground.
Is there continuity? YES - Repair short in the wire between the ECM/PCM (B4) and the secondary HO2S (Sensor 2), then go to 22. NO - Go to 28. |
| 16. | Measure voltage between secondary HO2S (Sensor 2) 4P connector terminal No. 3 and body ground.
Is there battery voltage? YES - Go to 17. NO - Repair open in the wire between the secondary HO2S (Sensor 2) and the No. 3 ALTERNATOR (10 A) fuse, then go to 22. |
| 17. | Turn the ignition switch OFF. |
| 18. | Jump the SCS line with the HDS. |
| 19. | Disconnect ECM/PCM connector B (44P). |
| 20. | Check for continuity between secondary HO2S (Sensor 2) 4P connector terminal No. 4 and ECM/PCM connector terminal B4.
Is there continuity? YES - Go to 28. NO - Repair open in the wire between the ECM/PCM (B4) and the secondary HO2S (Sensor 2), then go to 22. |
| 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. | Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0141 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 27. |
| 27. | Monitor the OBD STATUS for DTC P0141 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 NOT COMPLETED, go to 25 and recheck. |
| 28. | Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM. |
| 29. | Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0141 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 |