DTC Troubleshooting
DTC P0141: Secondary HO2S (Sensor 2) Heater Circuit MalfunctionNOTE:
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
- Information marked with an asterisk (*) applies to '06-07 models.
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 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 ECM/PCM.
5. Turn the ignition switch OFF.
6. Check the No. 18 ACG (15 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES - Go to step 7.
NO - Repair short in the wire between the secondary HO2S (Sensor 2) and the No. 18 ACG (15 A) fuse. Also replace the No. 18 ACG (15 A) fuse, then Go to step 23.
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 - 7.3 ohms at room temperature?
YES - Go to step 9.
NO - Go to step 22.
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 step 22.
NO - Go to step 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 step 12.
NO - Go to step 16.
12. Turn the ignition switch OFF.
13. Jump the SCS line with the HDS.
14. Disconnect ECM/PCM connector E (31P).
15. Check for continuity between ECM/PCM connector terminal E21 and body ground.
Is there continuity?
YES -Repair short in the wire between the ECM/PCM (E21) and the secondary HO2S (Sensor 2), then Go to step 23.
NO - Go to step 29.
16. Measure voltage between secondary HO2S (Sensor 2) 4P connector terminal No. 4 and body ground.
Is there battery voltage?
YES - Go to step 17.
NO - Repair open in the wire between the secondary HO2S (Sensor 2) and the No. 18 ACG (15 A) fuse, then Go to step 23.
17. Turn the ignition switch OFF.
18. Jump the SCS line with the HDS.
19. Disconnect ECM/PCM connector E (31P).
20. Connect secondary HO2S (Sensor 2) 4P connector terminal No. 3 to body ground with a jumper wire.
21. Check for continuity between ECM/PCM connector terminal E21 and body ground.
Is there continuity?
YES - Go to step 29.
NO - Repair open in the wire between the ECM/PCM (E21) and the secondary HO2S (Sensor 2), then Go to step 23.
22. Replace the secondary HO2S (Sensor 2).
23. Reconnect all connectors.
24. Turn the ignition switch ON (II).
25. Reset the ECM/PCM with the HDS.
26. Do the ECM/PCM idle learn procedure.
27. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0141 indicated?
YES - Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM/PCM, then Go to step 1.
NO - Go to step 28.
28. Monitor the OBD STATUS for DTC P0141 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated instep 27, Go to the indicated DTC's troubleshooting.
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 step 1. If the screen indicates NOT COMPLETED,keep idling until a result comes on.
29. Reconnect all connectors.
30. Update the ECM/PCM if it does not have the latest software, or substitute a known good ECM/PCM.
31. Start the engine, and let it idle.
32. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0141 indicated?
YES - Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the ECM/PCM. If the ECM/PCM was updated, substitute a known good ECM/PCM, then Go to step 31. If the ECM/PCM was substituted, Go to step 1.
NO - Go to step 33.
33. Monitor the OBD STATUS for DTC P0141 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM. If any other Temporary DTCs or DTCs were indicated in step 32, 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 ECM/PCM. If the ECM/PCM was updated, substitute a known good ECM/PCM, then Go to step 31. If the ECM/PCM was substituted, Go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.