DTC Troubleshooting
DTC Troubleshooting: P0141, P0161
DTC P0141:
Rear Secondary HO2S (Bank 1, Sensor 2) Heater Circuit Malfunction
DTC P0161:
Front Secondary HO2S (Bank 2, Sensor 2) Heater Circuit Malfunction
NOTE:
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information Initial Inspection and Diagnostic Overview.
- Information marked with an asterisk (*) applies to the front bank (Bank 2).
1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
2. Clear the DTC with the HDS.
3. Start the engine.
4. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0141 and/or P0161* indicated?
YES -
Go to step 5.
NO -
Intermittent failure, the systems is OK at this time. Check for poor connections or loose terminals at secondary HO2S (Sensor 2), the PGM-FI subrelay, and the PCM.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Check the No. 14 FI SUB (15 A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES -
Go to step 7.
NO -
Go to step 19.
7. Remove the PGM-FI subrelay (A) from the under-hood fuse/relay box.
8. Test the PGM-FI subrelay Testing and Inspection.
Is the relay OK?
YES -
Go to step 9.
NO -
Replace the PGM-FI subrelay, then go to step 25.
9. Disconnect the secondary HO2S (Sensor 2) 4P connector.
10. At the sensor side, measure the 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 11.
NO -
Go to step 24.
11. At the sensor 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 24.
NO -
Go to step 12.
12. Jump the SCS line with the HDS.
13. Disconnect PCM connector C (49P).
14. Check for continuity between PCM connector terminal C5 (C7)* and body ground.
Is there continuity?
YES -
Repair a short in the wire between the PCM (C5 (C7)*) and secondary HO2S (Sensor 2), then go to step 25.
NO -
Go to step 15.
15. Check for continuity between secondary HO2S (Sensor 2) 4P connector terminal No. 3 and PCM connector terminal C5 (C7)*.
Is there continuity?
YES -
Go to step 16.
NO -
Repair an open in the wire between the PCM (C5 (C7)*) and secondary HO2S (Sensor 2), then go to step 25.
16. Check for continuity between secondary HO2S (Sensor 2) 4P connector terminal No. 4 and PGM-FI subrelay 4P connector terminal No. 2.
Is there continuity?
YES -
Go to step 17.
NO -
Repair an open in the wire between secondary HO2S (Sensor 2) and the PGM-FI subrelay, then go to step 25.
17. Disconnect PCM connector A (49P).
18. Check for continuity between PGM-FI subrelay 4P connector terminal No. 3 and PCM connector terminal A40.
Is there continuity?
YES -
Go to step 31.
NO -
Repair an open in the wire between the PGM-FI subrelay and the PCM (A40), then go to step 25.
19. Remove the PGM-FI subrelay (A) from the under-hood fuse/relay box.
20. Disconnect the front and rear secondary HO2S (Sensor 2) 4P connectors.
21. Disconnect the front and rear A/F sensor (Sensor 1) 6P connectors.
22. Disconnect the EVAP canister vent shut valve 2P connector.
23. Check for continuity between secondary HO2S (Sensor 2) 4P connector terminal No. 4 and body ground.
Is there continuity?
YES -
Repair a short in the wire between the PGM-FI subrelay and secondary HO2S (Sensor 2), then go to step 25.
NO -
Check the under-hood fuse/relay box, and replace it if needed Under-Hood Fuse/Relay Box Removal and Installation. Also replace the No. 14 FI SUB (15 A) fuse, then go to step 25.
24. Replace secondary HO2S (Sensor 2) Secondary HO2S Replacement.
25. Reconnect all connectors.
26. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
27. Reset the PCM with the HDS.
28. Do the PCM idle learn procedure PCM Idle Learn Procedure.
29. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0141 and/or P0161* indicated?
YES -
Check for poor connections or loose terminals at secondary HO2S (Sensor 2), the PGM-FI subrelay, and the PCM, then go to step 1.
NO -
Go to step 30.
30. Monitor the OBD STATUS for DTC P0141 and/or P0161* in the DTCs MENU with the HDS.
Does the HDS indicate PASSED?
YES -
Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 29, go to the indicated DTC's troubleshooting.
NO -
If the HDS indicates FAILED, check for poor connections or loose terminals at secondary HO2S (Sensor 2), the PGM-FI subrelay, and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, keep idling until a result comes on.
31. Reconnect all connectors.
32. Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM.
33. Start the engine, and let it idle.
34. Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0141 and/or P0161* indicated?
YES -
Check for poor connections or loose terminals at secondary HO2S (Sensor 2), the PGM-FI subrelay, and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 33. If the PCM was substituted, go to step 1.
NO -
Go to step 35.
35. Monitor the OBD STATUS for DTC P0141 and/or P0161* in the DTCs MENU with the HDS.
Does the HDS 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 34, go to the indicated DTC's troubleshooting.
NO -
If the HDS indicates FAILED, check for poor connections or loose terminals at secondary HO2S (Sensor 2), the PGM-FI subrelay, and the PCM. If the PCM was updated, substitute a known-good PCM, then go to step 33. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, keep idling until a result comes on.