SFI SYSTEM, Diagnostic DTC:P0136, P0137, P0138

DTC Code DTC Name
P0136 Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2)
P0137 Oxygen Sensor Circuit Low Voltage (Bank 1 Sensor 2)
P0138 Oxygen Sensor Circuit High Voltage (Bank 1 Sensor 2)

DESCRIPTION

Refer to DTC P0037 Click here.

Tech Tips

Sensor 2 refers to the sensor mounted behind the three way catalytic converter and located far from the engine assembly.

DTC No. DTC Detection Condition Trouble Area
P0136
  • Abnormal voltage output:

    During active air fuel ratio control, the following conditions (a) and (b) are met for a certain period of time (2 trip detection logic):


    • (a) Heated oxygen sensor voltage does not decrease to less than 0.21 V


    • (b) Heated oxygen sensor voltage does not increase to more than 0.69 V


  • Open or short in heated oxygen sensor (bank 1 sensor 2) circuit

  • Heated oxygen sensor (bank 1 sensor 2)

  • Air fuel ratio sensor (bank 1 sensor 1)

  • Gas leakage from exhaust system

  • EGR valve assembly

P0137
  • Low voltage (open):

    During active air fuel ratio control, the following conditions (a) and (b) are met for a certain period of time (2 trip detection logic):


    • (a) Heated oxygen sensor voltage output is less than 0.21 V


    • (b) Target air fuel ratio rich


  • Open in heated oxygen sensor (bank 1 sensor 2) circuit

  • Heated oxygen sensor (bank 1 sensor 2)

  • Air fuel ratio sensor (bank 1 sensor 1)

  • Gas leakage from exhaust system

  • EGR valve assembly

P0138
  • High voltage (short):

    During active air fuel ratio control, the following conditions (a) and (b) are met for a certain period of time (2 trip detection logic):


    • (a) Heated oxygen sensor voltage output is 0.69 V or more


    • (b) Target air fuel ratio lean


  • Short in heated oxygen sensor (bank 1 sensor 2) circuit

  • Heated oxygen sensor (bank 1 sensor 2)

  • Air fuel ratio sensor (bank 1 sensor 1)

  • EGR valve assembly

  • ECM

MONITOR DESCRIPTION




CONFIRMATION DRIVING PATTERN

Tech Tips

This confirmation driving pattern is used in the "Perform Confirmation Driving Pattern" procedure of the following diagnostic troubleshooting procedure.

Performing this confirmation pattern will activate the heated oxygen sensor monitor. (The catalyst monitor is performed simultaneously.) This is very useful for verifying the completion of a repair.

A005LVEE84

  1. Connect the intelligent tester to the DLC3.

  2. Turn the ignition switch to ON and turn the tester on.

  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).

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

  5. Turn the ignition switch to ON and turn the tester on. [A]

  6. Start the engine and warm it up until the ECT reaches 75°C (167°F) or higher. [B]

  7. Drive the vehicle at 70 to 100 km/h (44 to 63 mph) for 10 minutes or more. [C]

    CAUTION:

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

  8. Enter the following menus: Powertrain / Engine and ECT / DTC [D].

  9. Read the pending DTCs.

    Tech Tips


    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  11. Input the DTC: P0136, P0137 or P0138.

  12. Check the DTC judgment result.

    Intelligent Tester
    Tester Display Description
    NORMAL
    • DTC judgment completed

    • System normal

    ABNORMAL
    • DTC judgment completed

    • System abnormal

    INCOMPLETE
    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions

    UNKNOWN
    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

WIRING DIAGRAM

Refer to DTC P0031 Click here.

CAUTION / NOTICE / HINT

Tech Tips

Intelligent tester only:

Malfunctioning areas can be identified by performing the Control the Injection Volume function provided in the Active Test. The Control the Injection Volume function can help to determine whether the air fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.

The following instructions describe how to conduct the Control the Injection Volume operation using the intelligent tester.


  1. Connect the intelligent tester to the DLC3.

  2. Start the engine and turn the tester on.

  3. Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.

  4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.

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

  6. Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the tester.

Tech Tips


  • Change the fuel injection volume within the range of -12.0% to +12.0%. The injection volume can be changed in fine gradations.

  • Each sensor reacts in accordance with increases and decreases in the fuel injection volume.

Tester Display (Sensor) Injection Volume Status Voltage

AFS Voltage B1S1

(Air fuel ratio)

+12% Rich Less than 3.1 V

AFS Voltage B1S1

(Air fuel ratio)

-12% Lean More than 3.4 V

O2S B1S2

(Heated oxygen)

+12% Rich More than 0.55 V

O2S B1S2

(Heated oxygen)

-12% Lean Less than 0.4 V

Note

The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.

A005I8OE38

Note

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

Tech Tips


  • Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions 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.

  • If the OX1B wire from the ECM connector is short-circuited to the +B wire, DTC P0136 will be stored.

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

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

PROCEDURE


  1. READ OUTPUT DTC (DTC P0136, P0137 OR P0138)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

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

    5. Read the DTCs.

      Result
      Result Proceed to
      DTC P0138 is output A
      DTC P0137 is output B
      DTC P0136 is output C
      DTC P0136, P0137 or P0138 and other DTCs are output D

    B
    C
    D
    A
  2. READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / O2S B1S2.

    5. Allow the engine to idle.

    6. Read the heated oxygen sensor output voltage with the engine idling.

      Result
      Result Proceed to
      1.0 V or more A
      Less than 1.0 V B

    B
    A
  3. INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)


    1. A005HVCE09
      Text in Illustration
      *a

      Component without harness connected

      (Heated Oxygen Sensor)

      Disconnect the heated oxygen sensor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (+B) - 3 (OX1B) Always 10 kΩ or higher
    3. Reconnect the heated oxygen sensor connector.


    NG
    OK
  4. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)


    1. Disconnect the ECM connector.

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

      Standard Resistance
      for RHD
      Tester Connection Condition Specified Condition
      B23-22 (HT1B) - B23-103 (OX1B) Always 10 kΩ or higher
      for LHD
      Tester Connection Condition Specified Condition
      B22-22 (HT1B) - B22-103 (OX1B) Always 10 kΩ or higher
    3. Reconnect the ECM connector.


    OK
    NG
  5. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine.

    3. Turn the tester on.

    4. Warm up the engine.

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

    6. Change the fuel injection volume using the tester, and monitor the voltage output of the air fuel ratio sensor and heated oxygen sensor displayed on the tester.

      Tech Tips


      • Change the fuel injection volume within the range of -12% and +12%. The injection volume can be changed in fine gradations within this range.

      • The air fuel ratio sensor is displayed as AFS Voltage B1S1, and the heated oxygen sensor is displayed as O2S B1S2 on the intelligent tester.

      • The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.

      • If the output voltage has almost no change, the air fuel ratio sensor may have a malfunction.

      Result
      Tester Display (Sensor) Voltage Variation Proceed to
      AFS Voltage B1S1 (Air fuel ratio) Alternates between more and less than 3.3 V OK
      AFS Voltage B1S1 (Air fuel ratio) Remains at more than 3.3 V NG
      AFS Voltage B1S1 (Air fuel ratio) Remains at less than 3.3 V NG

      Tech Tips

      A normal heated oxygen sensor voltage (O2S B1S2) reacts in accordance with increases and decreases in fuel injection volumes. When the air fuel ratio sensor voltage remains at either less or more than 3.3 V despite the heated oxygen sensor indicating a normal reaction, the air fuel ratio sensor is malfunctioning.

      A005LLBE02

    NG
    OK
  6. INSPECT AIR FUEL RATIO SENSOR

    Tech Tips

    This air fuel ratio sensor test is to check the air fuel ratio sensor current during the fuel cut operation. When the sensor is normal, the sensor current will indicate less than 3.0 mA in this test.


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Drive the vehicle by the drive pattern as listed below:

      CAUTION:

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


      1. Warm up the engine.

      2. Drive the vehicle at 60 km/h (37 mph) or more for 10 minutes or more.

      3. Stop the vehicle.

      4. Accelerate the vehicle up to 60 km/h (37 mph) or more and then decelerate for 5 seconds or more. Perform this least 3 times.

        A005I2KE32
    6. Enter the following menus: Powertrain / Engine and ECT / Data List / A/F Control System / AFS Current B1S1.

    7. Read the value of the air fuel ratio sensor current while fuel cut is occurring.

      Standard Current
      Less than 2.2 mA

      Tech Tips


      • To measure the air fuel ratio sensor current precisely, perform the fuel-cut operation as long as possible.

      • If it is difficult to measure the air fuel ratio sensor current, use the snapshot function of the intelligent tester.


    OK
    NG
  7. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE INJECTION VOLUME)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine.

    3. Turn the tester on.

    4. Warm up the engine.

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume / O2S B1S2.

    6. Change the fuel injection volume using the tester, monitoring the voltage output of the heated oxygen sensors displayed on the tester.

      Tech Tips


      • Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine gradations within this range.

      • The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.

      Standard voltage
      Fluctuates between 0.4 V or less and 0.55 V or more.

    NG
    OK
  8. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the tester on.

    3. Start the engine.

    4. Warm up the engine.

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

    6. Change the fuel injection volume using the tester and monitor the voltage output of the air fuel ratio and heated oxygen sensors displayed on the tester.

      Tech Tips


      • Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine gradations within this range.

      • The air fuel ratio sensor is displayed as AFS Voltage B1S1, and the heated oxygen sensor is displayed as O2S B1S2 on the tester.

      • The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.

      • If the output voltage has almost no change, the air fuel ratio sensor may have a malfunction.

      Result
      Tester Display (Sensor) Voltage Variation Proceed to
      AFS Voltage B1S1 (Air fuel ratio) Alternates between more and less than 3.3 V OK
      AFS Voltage B1S1 (Air fuel ratio) Remains at more than 3.3 V NG
      AFS Voltage B1S1 (Air fuel ratio) Remains at less than 3.3 V NG

      Tech Tips

      A normal heated oxygen sensor voltage (O2S B1S2) reacts in accordance with increases and decreases in fuel injection volumes. When the air fuel ratio sensor voltage remains at either below or higher than 3.3 V despite the heated oxygen sensor indicating a normal reaction, the air fuel ratio sensor is malfunctioning.

      A005LLBE02

    NG
    OK
  9. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or more.

      Tech Tips

      The A/C switch and all accessory switches should be off.

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.

    6. Confirm that the Throttle Idle Position is ON and check the engine idling condition and MAP values in the Data List while performing the Active Test.

      OK
      MAP and idling condition change in response to EGR step position.
      Standard
      - EGR Step Position (Active Test)
      0 Steps 0 to 30 Steps
      Idling condition Steady idling Idling changes from steady to rough idling

      MAP

      (Data List)

      MAP value is 28 to 48 kPa

      (210 to 360 mmHg)

      (EGR valve is fully closed)

      MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

      Tech Tips


      • Do not leave the EGR valve open for 10 seconds or more during the Active Test.

      • Be sure to return the EGR valve to step 0 when the Active Test is completed.

      • During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve.

      Result
      Result Proceed to
      Outside of standard range A
      Within standard range B

    B
    A
  10. INSPECT EGR VALVE ASSEMBLY


    1. Remove the EGR valve assembly Click here.

    2. Check for contamination between the EGR valve and housing.

      OK
      No leaks or blockage.

    OK
    NG
  11. CHECK FOR EXHAUST GAS LEAK


    1. Check for exhaust gas leakage.

      OK
      No gas leakage.

    NG
    OK
  12. INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)


    1. A005HVCE06
      Text in Illustration
      *a

      Component without harness connected

      (Heated Oxygen Sensor)

      Disconnect the heated oxygen sensor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (HT1B) - 2 (+B) 20°C (68°F) 11 to 16 Ω
      1 (HT1B) - 4 (E2) Always 10 kΩ or higher
    3. Reconnect the heated oxygen sensor connector.


    NG
    OK
  13. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)


    1. Disconnect the heated oxygen sensor connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      for RHD
      Tester Connection Condition Specified Condition
      B37-1 (HT1B) - B23-22 (HT1B) Always Below 1 Ω
      B37-3 (OX1B) - B23-103 (OX1B) Always Below 1 Ω
      B37-4 (E2) - B23-135 (EX1B) Always Below 1 Ω
      for LHD
      Tester Connection Condition Specified Condition
      B37-1 (HT1B) - B22-22 (HT1B) Always Below 1 Ω
      B37-3 (OX1B) - B22-103 (OX1B) Always Below 1 Ω
      B37-4 (E2) - B22-135 (EX1B) Always Below 1 Ω
      Standard Resistance (Check for Short)
      for RHD
      Tester Connection Condition Specified Condition
      B37-1 (HT1B) or B23-22 (HT1B) - Body ground Always 10 kΩ or higher
      B37-3 (OX1B) or B23-103 (OX1B) - Body ground Always 10 kΩ or higher
      B37-4 (E2) or B23-135 (EX1B) - Body ground Always 10 kΩ or higher
      for LHD
      Tester Connection Condition Specified Condition
      B37-1 (HT1B) or B22-22 (HT1B) - Body ground Always 10 kΩ or higher
      B37-3 (OX1B) or B22-103 (OX1B) - Body ground Always 10 kΩ or higher
      B37-4 (E2) or B22-135 (EX1B) - Body ground Always 10 kΩ or higher
    4. Reconnect the heated oxygen sensor connector.

    5. Reconnect the ECM connector.


    NG
    OK
  14. REPLACE HEATED OXYGEN SENSOR


    1. Replace the heated oxygen sensor Click here.


    NEXT
  15. PERFORM CONFIRMATION DRIVING PATTERN


    1. Perform the confirmation driving pattern.


    NEXT
  16. CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137 OR P0138)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    5. Clear the DTCs Click here.

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

    7. Input DTC: P0136, P0137 or P0138.

      Check that the STATUS is NORMAL. If the STATUS is INCOMPLETE, perform the driving pattern increasing the vehicle speed and using the second gear to decelerate the vehicle.

      Result
      Result Proceed to
      ABNORMAL A
      NORMAL B

    B
    A
  17. READ VALUE USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or more.

      Tech Tips

      The A/C switch and all accessory switches should be off.

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.

    6. Confirm that the Throttle Idle Position is ON and check the engine idling condition and MAP values in the Data List while performing the Active Test.

      OK
      MAP and idling condition change in response to EGR step position.
      Standard
      - EGR Step Position (Active Test)
      0 Steps 0 to 30 Steps
      Idling condition Steady idling Idling changes from steady to rough idling

      MAP

      (Data List)

      MAP value is 28 to 48 kPa

      (210 to 360 mmHg)

      (EGR valve is fully closed)

      MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

      Tech Tips


      • Do not leave the EGR valve open for 10 seconds or more during the Active Test.

      • Be sure to return the EGR valve to step 0 when the Active Test is completed.

      • During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve.

      Result
      Result Proceed to
      Outside of standard range A
      Within standard range B

      Tech Tips

      Perform "Inspection After Repairs" after replacing the air fuel ratio sensor Click here.


    B
    A
  18. INSPECT EGR VALVE ASSEMBLY


    1. Remove the EGR valve assembly Click here.

    2. Check for contamination between the EGR valve and housing.

      OK
      No leaks or blockage.
    3. Reinstall the EGR valve assembly Click here.

      Tech Tips

      Perform "Inspection After Repairs" after replacing the air fuel ratio sensor Click here.


    OK
    NG
  19. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.

      Tech Tips

      Perform "Inspection After Repairs" after replacing the air fuel ratio sensor Click here.


    NEXT
  20. PERFORM CONFIRMATION DRIVING PATTERN


    1. Perform the confirmation driving pattern.


    NEXT
  21. CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137 OR P0138)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    5. Clear the DTCs Click here.

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

    7. Input DTC: P0136, P0137 or P0138.

      Check that the STATUS is NORMAL. If the STATUS is INCOMPLETE, perform the driving pattern increasing the vehicle speed and using the second gear to decelerate the vehicle.

      Result
      Result Proceed to
      ABNORMAL A
      NORMAL B

    B
    A
  22. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or more.

      Tech Tips

      The A/C switch and all accessory switches should be off.

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.

    6. Confirm that the Throttle Idle Position is ON and check the engine idling condition and MAP values in the Data List while performing the Active Test.

      OK
      MAP and idling condition change in response to EGR step position.
      Standard
      - EGR Step Position (Active Test)
      0 Steps 0 to 30 Steps
      Idling condition Steady idling Idling changes from steady to rough idling

      MAP

      (Data List)

      MAP value is 28 to 48 kPa

      (210 to 360 mmHg)

      (EGR valve is fully closed)

      MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

      Tech Tips


      • Do not leave the EGR valve open for 10 seconds or more during the Active Test.

      • Be sure to return the EGR valve to step 0 when the Active Test is completed.

      • During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve.

      Result
      Result Proceed to
      Outside of standard range A
      Within standard range B

    B
    A
  23. INSPECT EGR VALVE ASSEMBLY


    1. Remove the EGR valve assembly Click here.

    2. Check for contamination between the EGR valve and housing.

      OK
      No leaks or blockage.
    3. Reinstall the EGR valve assembly Click here.


    OK
    NG