SFI SYSTEM, Diagnostic DTC:P0139

DTC Code DTC Name
P0139 Oxygen Sensor Circuit Slow Response (Bank 1 Sensor 2)

DESCRIPTION

Refer to DTC P0137 Click here.

DTC No. DTC Detection Condition Trouble Area
P0139

No. 2 heated oxygen sensor is stuck lean:


  • Air fuel ratio of No. 2 heated oxygen sensor does not change for 50 seconds continuously even when vehicle is driven in an urban area with many hills for approximately 20 minutes or more (3 trip detection logic).

  • Open or short in No. 2 heated oxygen sensor circuit

  • No. 2 heated oxygen sensor

  • Fuel pressure

  • Fuel injector assembly

  • Gas leak from exhaust system

No. 2 heated oxygen sensor is stuck rich:


  • Output voltage of No. 2 heated oxygen sensor does not become lower than 0.25 V even though fuel-cut is performed continuously for 5.5 seconds or more when vehicle is driven in an urban area with many hills for approximately 20 minutes or more (3 trip detection logic).

WIRING DIAGRAM

Refer to DTC P0130 Click here.

CONFIRMATION DRIVING PATTERN

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

DTC P0139 is detected when the vehicle is driven in an urban area with many hills for approximately 20 minutes or more.

CAUTION / NOTICE / HINT

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips


  • Sensor 1 refers to the sensor closest to the engine assembly.

  • Sensor 2 refers to the sensor farthest away from the engine assembly.

  • Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE


  1. CHECK ANY OTHER DTC OUTPUT (IN ADDITION TO DTC P0139)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    5. Read DTCs.

      Result
      Result Proceed to
      DTC P0139 is output A
      DTC P0139 and other DTCs are output B

      Tech Tips

      If any DTCs other than P0139 are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)


    1. Connect the GTS to the DLC3.

    2. Start the engine.

    3. Turn the GTS on.

    4. Warm up the engine at an engine speed of 2500 rpm for approximately 3 minutes.

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.

    6. Perform the Active Test operation with the engine idling (press the -12.5 or 12.5 button to change the fuel injection volume).

    7. Monitor the voltage output of the heated oxygen sensor and No. 2 heated oxygen sensor (O2S B1S1 and O2S B1S2) displayed on the GTS.

      Tech Tips


      • The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 12.5%.

      • The heated oxygen sensor has an output delay of a few seconds and the No. 2 heated oxygen sensor has a maximum output delay of approximately 20 seconds.

      • If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

      Result
      The heated oxygen sensors reacts in accordance with increases and decreases of the fuel injection volume:
      12.5% = Rich output
      Higher than 0.55 V
      -12.5% = Lean output
      Below 0.4 V
      A01VDMFE02

      The following procedure enables the technician to check and graph the voltage outputs of both the heated oxygen sensors.

      To display the graph, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / O2S B1S1 and O2S B1S2; then press the view button.

      Tech Tips

      If the vehicle is short of fuel, the air fuel ratio becomes lean and the heated oxygen sensor DTCs are recorded, and then the MIL illuminates.

      Result
      Result Proceed to
      Case 2 A
      Case 3 B
      Case 1 C

    B

    CHECK WHETHER MISFIRE OCCURS Click here

    C

    CHECK WHETHER DTC OUTPUT RECURS (DTC P0139) Click here

    A

  3. CHECK HARNESS AND CONNECTOR (NO. 2 HEATED OXYGEN SENSOR - ECM)


    1. Disconnect the B83 No. 2 heated oxygen sensor connector.

    2. Disconnect the B97 ECM connector (for LHD).

    3. Disconnect the B101 ECM connector (for RHD).

    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      B83-4 (OX1B) - B97-103 (OX1B) Always Below 1 Ω
      B83-2 (HT1B) - B97-25 (HT1B) Always Below 1 Ω
      B83-3 (E1) - B97-135 (E12) Always Below 1 Ω
      B83-4 (OX1B) or B97-103 (OX1B) - Body ground Always 10 kΩ or higher
      B83-2 (HT1B) or B97-25 (HT1B) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      B83-4 (OX1B) - B101-103 (OX1B) Always Below 1 Ω
      B83-2 (HT1B) - B101-25 (HT1B) Always Below 1 Ω
      B83-3 (E1) - B101-135 (E12) Always Below 1 Ω
      B83-4 (OX1B) or B101-103 (OX1B) - Body ground Always 10 kΩ or higher
      B83-2 (HT1B) or B101-25 (HT1B) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. REPLACE NO. 2 HEATED OXYGEN SENSOR


    1. Replace the No. 2 heated oxygen sensor Click here.


    NEXT

  5. CHECK WHETHER DTC OUTPUT RECURS (DTC P0139)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear DTCs Click here.

    5. Turn the ignition switch off and wait for 30 seconds.

    6. Turn the ignition switch to ON.

    7. Turn the GTS on.

    8. Start the engine and warm it up.

    9. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    10. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    11. Read the pending DTCs.

      Result
      Result Proceed to
      DTC is not output A
      DTC P0139 is output B

    A

    END

    B

  6. CHECK WHETHER MISFIRE OCCURS


    1. Check the idling condition.

      OK
      Rough idling does not occur.

    NG

    TROUBLESHOOT MISFIRE Click here

    OK

  7. CHECK FUEL PRESSURE


    1. Check the fuel pressure Click here.


    NG

    REPAIR OR REPLACE FUEL SYSTEM

    OK

  8. INSPECT FUEL INJECTOR ASSEMBLY (INJECTION AND VOLUME)


    1. Check the injector volume Click here.


    OK

    CHECK FOR EXHAUST GAS LEAK

    NG

    REPLACE FUEL INJECTOR ASSEMBLY Click here

  9. CHECK WHETHER DTC OUTPUT RECURS (DTC P0139)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear DTCs Click here.

    5. Turn the ignition switch off and wait for 30 seconds.

    6. Turn the ignition switch to ON.

    7. Turn the GTS on.

    8. Start the engine and warm it up.

    9. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    10. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    11. Read the pending DTCs.

      Result
      Result Proceed to
      DTC P0139 is output A
      DTC is not output B

    A

    REPLACE NO. 2 HEATED OXYGEN SENSOR Click here

    B

    CHECK FOR INTERMITTENT PROBLEMS Click here