P0141
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.
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, 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. 3 ALTERNATOR (10 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. 3 ALTERNATOR (10 A) fuse. Also replace the No. 3 ALTERNATOR (10 A) fuse, then go to step 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 Ohm at room temperature?
Yes - Go to step 9.
NO - Go to step 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 step 21.
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 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 step 22.
NO - Go to step 28.
16. Measure voltage between secondary HO2S (Sensor 2) 4P connector terminal No. 3 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. 3 ALTERNATOR (10 A) fuse, then go to step 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 step 28.
NO - Repair open in the wire between the ECM/PCM (B4) and the secondary HO2S (Sensor 2), then go to step 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 step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
NO - Go to step 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.
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, go to step 25 and recheck.
28. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
29. Start the engine.
30. 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 update, substitute a known-good ECM/PCM, then go to step 29. If the ECM/PCM was substitute, go to step 1.
NO - If no Temporary DTCs or DTCs are indicated, go to step 31. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
31. 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.
NO - If the screen indicates FAILED, 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 29. If the ECM/PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, let the engine idle until a result comes on.