DTC Troubleshooting: P0139 (63)

DTC P0139:  Slow Response in Secondary HO2S (Sensor 2) Circuit


1.Turn the ignition switch ON (ll).

2.Do the DTC CLEAR in the CLEAR MENU with the Honda PGM Tester or the HDS.

3.Start the engine. Hold the engine speed at 3,000 rpm (min-1) with no load (in Park or neutral) until the radiator fan comes on, then let it idle.

4.Test-drive with the throttle fully opened, then slow down with the throttle completely closed for 3 seconds.

5.Monitor the OBD STATUS for DTC P0139 in the DTCs MENU with the Honda PGM Tester or the HDS.

Is it FAILED?


YES - Go to 6.


NO - If it is PASSED, intermittent failure, system is OK at this time. If it is EXECUTING, keep the driving condition continually until a result comes on. If it is Out of CONDITION, go to 3. and recheck.


6.Turn the ignition switch OFF.

7.Replace the secondary HO2S (Sensor 2).

8.Turn the ignition switch ON (II).

9.Do the ECM/PCM RESET in the CLEAR MENU with the Honda PGM Tester or the HDS.

10.Do the ECM/PCM idle learn procedure.

11.Test-drive with the throttle fully opened, then slow down with the throttle completely closed for 3 seconds.

12.Check for Temporary DTCs or DTCs in the DTCs MENU with the Honda PGM Tester or the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0139 is indicated, check for poor connections or loose terminals at the  secondary HO2S (Sensor 2) and the  ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting.


NO - Go to 13.


13.Monitor the OBD STATUS for DTC P0139 in the DTCs MENU with the Honda PGM Tester or the HDS.

Is it PASSED?


YES - Troubleshooting is complete.n


NO - If it is FAILED, check for poor connections or loose terminals at the  secondary HO2S (Sensor 2) and the  ECM/PCM, then go to 1. If it is EXECUTING, keep the driving condition continually until a result comes on. If it is Out of CONDITION, go to 11 and recheck.