DTC P0141: Secondary HO2S (Sensor 2) Heater Circuit Malfunction

WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine.
Check for Pending or Confirmed 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 secondary HO2S (Sensor 2) and the PCM.
Turn the ignition switch to LOCK (0).
Check the No. 12 IMA (10 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?

YES -Go to step 7.

NO -Repair a short in the wire between secondary HO2S (Sensor 2), the idle stop switch, the EVAP canister purge valve, the MAF sensor, and the No. 12 IMA (10 A) fuse. Also replace the No. 12 IMA (10 A) fuse, then go to step 23.
Remove the cowl cover and the under-cowl panel (see COWL COVER REPLACEMENT ).
Disconnect the secondary HO2S (Sensor 2) 4P connector.
At the secondary HO2S (Sensor 2) side, measure the resistance between secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4.

Fig 1: Measuring Resistance Between Secondary HO2S (Sensor 2) 4P Connector Terminals No. 3 And No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there 5.4-7.3 Ω at room temperature?

YES -Go to step 10.

NO -Go to step 22.
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.

Fig 2: Checking Continuity Between Body Ground And Secondary HO2S (Sensor 2) 4P Connector Terminals No. 3 And No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 22.

NO -Go to step 11.
Turn the ignition switch to ON (II).
Measure the voltage between secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4.

Fig 3: Measuring Voltage Between Secondary HO2S (Sensor 2) 4P Connector Terminals No. 3 And No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 13.

NO -Go to step 17.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector C (44P).
Check for continuity between PCM connector terminal C28 and body ground.

Fig 4: Checking Continuity Between PCM Connector Terminal C28 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short in the wire between the PCM (C28) and secondary HO2S (Sensor 2), then go to step 23.

NO -Go to step 29.
Measure the voltage between secondary HO2S (Sensor 2) 4P connector terminal No. 3 and body ground.

Fig 5: Measuring Voltage Between Secondary HO2S (Sensor 2) 4P Connector Terminal No. 3 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 18.

NO -Repair an open in the wire between secondary HO2S (Sensor 2) and the No. 12 IMA (10 A) fuse, then go to step 23.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect PCM connector C (44P).
Check for continuity between PCM connector terminal C28 and secondary HO2S (Sensor 2) 4P connector terminal No. 4.

Fig 6: Checking Continuity Between PCM Connector Terminal C28 And Secondary HO2S (Sensor 2) 4P Connector Terminal No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 29.

NO -Repair an open in the wire between the PCM (C28) and secondary HO2S (Sensor 2), then go to step 23.
Replace secondary HO2S (Sensor 2) (see A/F SENSOR REPLACEMENT ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0141 indicated?

YES -Check for poor connections or loose terminals at secondary HO2S (Sensor 2) and the PCM, then go to step 1.

NO -Go to step 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 Pending or Confirmed DTCs were indicated in step 27, 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 PCM, then go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.
Reconnect all connectors.
Update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ).
Start the engine, and let it idle.
Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0141 indicated?

YES -Check for poor connections or loose terminals at secondary HO2S (Sensor 2) and the PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then go to step 31. If the PCM was substituted, go to step 1.

NO -Go to step 33.
Monitor the OBD STATUS for DTC P0141 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see PCM REPLACEMENT ). If any other Pending or Confirmed 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 PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then go to step 31. If the PCM was substituted, go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.