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

WARNING: This page is about a different car, the 2013 Honda Fit, 2012 Honda Fit, 2011 Honda Fit, 2010 Honda Fit, and 2009 Honda Fit. 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 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 the secondary HO2S (Sensor 2) and the ECM/PCM.
Turn the ignition switch to LOCK (0).
Check the No. 12 ACG (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. 12 ACG (ALTERNATOR) (10 A) fuse. Also replace the No. 12 ACG (ALTERNATOR) (10 A) fuse, then go to step 23.
Remove the under-cowl panel (see UNDER-COWL PANEL 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.
Is there 5.4 - 7.3 Ω at room temperature?

YES: Go to step 10.

NO: Go to step 22.

Fig 1: Measuring Resistance Between Secondary HO2S (Sensor 2) 4P Connector Terminals No. 3 & No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.
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 11.

Fig 2: Checking Continuity Between Body Ground & Secondary HO2S (Sensor 2) 4P Connector Terminals No. 3 & No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to ON (II).
Measure the voltage between secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4.
Is there battery voltage?

YES: Go to step 13.

NO: Go to step 17.

Fig 3: Measuring Voltage Between Secondary HO2S (Sensor 2) 4P Connector Terminals No. 3 & No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect ECM/PCM connector B (49P).
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 23.

NO: Go to step 29.

Fig 4: Checking Continuity Between ECM/PCM Connector Terminal B4 & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Measure the voltage between secondary HO2S (Sensor 2) 4P connector terminal No. 3 and body ground.
Is there battery voltage?

YES: Go to step 18.

NO: Repair open in the wire between the secondary HO2S (Sensor 2) and the No. 12 ACG (ALTERNATOR) (10 A) fuse, then go to step 23.

Fig 5: Measuring Voltage Between Secondary HO2S (Sensor 2) 4P Connector Terminal No. 3 & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect ECM/PCM connector B (49P).
Check for continuity between ECM/PCM connector terminal B4 and secondary HO2S (Sensor 2) 4P connector terminal No. 4.
Is there continuity?

YES: Go to step 29.

NO: Repair open in the wire between the ECM/PCM (B4) and the secondary HO2S (Sensor 2), then go to step 23.

Fig 6: Checking Continuity Between ECM/PCM Connector Terminal B4 & Secondary HO2S (Sensor 2) 4P Connector Terminal No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Replace the secondary HO2S (Sensor 2) (see SECONDARY HO2S REPLACEMENT ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the ECM/PCM with the HDS.
Do ECM/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 the secondary HO2S (Sensor 2) and the ECM/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 HDS 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 HDS indicates NOT COMPLETED, keep idling until a result comes on.
Reconnect all connectors.
Update the ECM/PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/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 the secondary HO2S (Sensor 2) and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step 31. If the ECM/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 ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ). If any other Pending or Confirmed DTCs were indicated in step 32, go to the indicated DTC's troubleshooting.

NO: If the HDS 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 (see SUBSTITUTING THE ECM/PCM ), then go to step 31. If the ECM/PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, keep idling until a result comes on.