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.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0139

Oxygen Sensor Circuit Slow Response (Bank 1 Sensor 2)

  • Heated oxygen sensor (sensor 2) is stuck lean:

    • Air-fuel ratio of heated oxygen sensor (sensor 2) 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).

  • Heated oxygen sensor (sensor 2) is stuck rich:

    • Output voltage of heated oxygen sensor (sensor 2) 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).

  • Open or short in heated oxygen sensor (sensor 2) circuit

  • Heated oxygen sensor (sensor 2)

  • Fuel pressure

  • Fuel injector assembly

  • Gas leakage from exhaust system

Comes on

DTC stored (Euro-OBD)

- (except Euro-OBD)

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

Tip:
  • 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 the DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      DTC P0139 is output

      A

      DTC P0139 and other DTCs are output

      B

      Tip:

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

    B

    GO TO DTC CHART

    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 / All Data / O2S B1S1 and O2S B1S2.

      Powertrain > Engine and ECT > Active Test

      Active Test Display

      Control the Injection Volume for A/F Sensor

      Data List Display

      O2S B1S1

      O2S B1S2

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

    7. Monitor the voltage output of the heated oxygen sensor (sensor 1) and heated oxygen sensor (sensor 2) (O2S B1S1 and O2S B1S2) displayed on the GTS.

      Tip:
      • 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 (sensor 1) has an output delay of a few seconds and the heated oxygen sensor (sensor 2) 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

      A318964E03

      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 / All Data / O2S B1S1 and O2S B1S2; then press the view button.

      Tip:

      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 OCCURSClick here

    C

    CHECK WHETHER DTC OUTPUT RECURS (DTC P0139)Click here

    A
  3. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR (SENSOR 2) - ECM)

    1. Disconnect the heated oxygen sensor (sensor 2) connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      B18-4 (OX1B) - B31-103 (OX1B)

      Always

      Below 1 Ω

      B18-2 (HT1B) - B31-25 (HT1B)

      Always

      Below 1 Ω

      B18-3 (E1) - B31-135 (E12)

      Always

      Below 1 Ω

      B18-4 (OX1B) or B31-103 (OX1B) - Body ground

      Always

      10 kΩ or higher

      B18-2 (HT1B) or B31-25 (HT1B) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK
  4. REPLACE HEATED OXYGEN SENSOR (SENSOR 2)

    1. Replace the heated oxygen sensor (sensor 2).

      Click hereClick here

    Result

    Proceed to

    NEXT

    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 the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

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

    6. Start the engine and warm it up.

    7. Turn the GTS on.

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

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

    10. Read the pending DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      DTCs are 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.

    Result

    Proceed to

    OK

    NG

    NG

    TROUBLESHOOT MISFIRE

    OK
  7. CHECK FUEL PRESSURE

    1. Check the fuel pressure.

      Click here

    Result

    Proceed to

    OK

    NG

    NG

    REPAIR OR REPLACE FUEL SYSTEM

    OK
  8. INSPECT FUEL INJECTOR ASSEMBLY (INJECTION AND VOLUME)

    1. Check the injector volume.

      Click here

    Result

    Proceed to

    OK

    NG

    OK

    CHECK FOR EXHAUST GAS LEAK

    NG

    REPLACE FUEL INJECTOR ASSEMBLY

  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 the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

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

    6. Start the engine and warm it up.

    7. Turn the GTS on.

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

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

    10. Read the pending DTCs.

      Powertrain > Engine and ECT > Trouble Codes

      Result

      Result

      Proceed to

      DTC P0139 is output

      A

      DTCs are not output

      B

    A

    REPLACE HEATED OXYGEN SENSOR (SENSOR 2)

    B

    CHECK FOR INTERMITTENT PROBLEMS