SFI SYSTEM, Diagnostic DTC:P0136, P0137, P0138, P0156, P0157, P0158

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)
P0156 Oxygen Sensor Circuit Malfunction (Bank 2 Sensor 2)
P0157 Oxygen Sensor Circuit Low Voltage (Bank 2 Sensor 2)
P0158 Oxygen Sensor Circuit High Voltage (Bank 2 Sensor 2)

CAUTION / NOTICE / HINT

Tech Tips

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

DESCRIPTION

A three-way catalytic converter is used in order to convert the carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (HOx) into less harmful substances. To allow the three-way catalytic converter to function effectively, it is necessary to keep the air fuel ratio of the engine near the stoichiometric air fuel ratio. For helping the ECM to deliver accurate air fuel ratio control, a heated oxygen sensor is used.

The heated oxygen sensor is located behind the three-way catalytic converter, and detects the oxygen concentration in the exhaust gas. Since the sensor is integrated with the heater that heats the sensing portion, it is possible to detect the oxygen concentration even when the intake air volume is low (the exhaust gas temperature is low).

When the air fuel ratio becomes lean, the oxygen concentration in the exhaust gas becomes rich. The heated oxygen sensor informs the ECM that the post-three-way catalytic converter air fuel ratio is lean (low voltage, i.e. less than 0.45 V).

Conversely, when the air fuel ratio is richer than the stoichiometric air fuel level, the oxygen concentration in the exhaust gas becomes lean. The heated oxygen sensor informs the ECM that the post-three-way catalytic converter air fuel ratio is rich (high voltage, i.e. more than 0.45 V). The heated oxygen sensor has the property of changing its output voltage drastically when the air fuel ratio is close to the stoichiometric level.

The ECM uses the supplementary information from the heated oxygen sensor to determine whether the air fuel ratio after the three-way catalytic converter is rich or lean, and adjusts the fuel injection time accordingly. Thus, if the heated oxygen sensor is working improperly due to internal malfunctions, the ECM is unable to compensate for deviations in the primary air fuel ratio control.

A017DM0E01
DTC No. DTC Detection Condition Trouble Area

P0136

P0156

  • Abnormal voltage output:

    During active air fuel ratio control, 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 0.2 V

    (b) Heated oxygen sensor voltage does not increase to more than 0.6 V


  • Low impedance:

    Sensor impedance less than 5 Ω for more than 30 seconds when ECM presumes sensor to being warmed up and operating normally (2 trip detection logic)

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

  • Heated oxygen sensor (bank 1, 2 sensor 2)

  • Heated oxygen sensor heater (bank 1, 2 sensor 2)

  • Air fuel ratio sensor (bank 1, 2 sensor 1)

  • Gas leakage from exhaust system

P0137

P0157

  • Low voltage (open):

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

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

    (b) Target air fuel ratio rich


  • High impedance:

    Sensor impedance 15 kΩ or more for more than 90 seconds when ECM presumes sensor to being warmed up and operating normally (2 trip detection logic)

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

  • Heated oxygen sensor (bank 1, 2 sensor 2)

  • Heated oxygen sensor heater (bank 1, 2 sensor 2)

  • Gas leakage from exhaust system

P0138

P0158

  • High voltage (short):

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

    (a) Heated oxygen sensor voltage output 0.59 V or more

    (b) Target air fuel ratio lean


  • Extremely high voltage (short):

    Heated oxygen sensor voltage output exceeds 1.2 V for more than 30 seconds (2 trip detection logic)

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

  • Heated oxygen sensor (bank 1, 2 sensor 2)

  • ECM internal circuit malfunction

WIRING DIAGRAM

A017DCJE06

CONFIRMATION DRIVING PATTERN

A017FCPE24

  1. Connect the intelligent tester to the DLC3.

  2. Warm-up the engine until the engine coolant temperature is 75°C (167°F) or more [A].

  3. Drive the vehicle at 60 to 120 km/h (40 to 75 mph) for at 10 minutes [B].

  4. Drive the vehicle 60 km/h (40 mph) or more and decelerate the vehicle for 5 seconds or more. Perform this 3 times [C].

  5. Turn the tester on.

  6. Select the following menu items: Powertrain / Engine / Utility / All Readiness.

  7. Input DTCs: P0136, P0137, P0138, P0156, P0157 and P0158.

  8. Check that DTC MONITOR is NORMAL. If DTC MONITOR is INCOMPLETE, perform the drive pattern adding the vehicle speed and using the second gear to decelerate the vehicle.

INSPECTION PROCEDURE

Tech Tips

For use of the intelligent tester only:

Malfunctioning areas can be identified by performing the Control the Injection Volume for air fuel ratio sensor function provided in the Active Test. The Control the Injection Volume for air fuel ratio sensor 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 for air fuel ratio sensor 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. Select the following menu items on the tester: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for air fuel ratio sensor.

  5. Perform the Control the Injection Volume for air fuel ratio sensor operation with the engine in an idling condition (press the Right or Left button to change the fuel injection volume).

  6. Monitor the voltage outputs of the air fuel ratio and heated oxygen sensors (AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2) displayed on the tester.

    Tech Tips


    • The Control the Injection Volume for air fuel ratio sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.

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

    Standard voltage
    Tester Display (Sensor) Injection Volume Status Voltage
    AFS B1S1 or AFS B2S1 (Air fuel ratio) +25% Rich Less than 3.0
    AFS B1S1 or AFS B2S1 (Air fuel ratio) -12.5% Lean More than 3.35
    O2S B1S2 or O2S B2S2 (Heated oxygen) +25% Rich More than 0.55
    O2S B1S2 or O2S B2S2 (Heated oxygen) -12.5% Lean Less than 0.4

    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.

    Case

    Air Fuel Ratio Sensor (Sensor 1)

    Output Voltage

    Heated Oxygen Sensor (Sensor 2)

    Output Voltage

    		 Main Suspected Trouble Area
    1 A017EWCE01 A017EFTE02 -
    2 A017EP5E01 A017EFTE02

    • Air fuel ratio sensor

    • Air fuel ratio sensor heater

    • Air fuel ratio sensor circuit
    3 A017EWCE01 A017EP5E01

    • Heated oxygen sensor

    • Heated oxygen sensor heater

    • Heated oxygen sensor circuit
    4 A017EP5E01 A017EP5E01

    • Fuel pressure

    • Gas leakage from exhaust system

      (Air fuel ratio extremely lean or rich)

    • Following the Control the Injection Volume for air fuel ratio sensor procedure enables technicians to check and graph the voltage outputs of both the air fuel ratio and heated oxygen sensors.

    • The following air fuel ratio control procedure enables the technician to check and graph the voltage output of both the heated oxygen sensors. To display the graph, select the following menu items on the tester: View / Line Graph.

      Tech Tips


      • If other DTCs relating to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.

      • Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

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

      • If the OX2B wire from the ECM connector is short-circuited to the +B wire, DTC P0156 will be set.

PROCEDURE


  1. READ DTC OUTPUT (DTC P0136, P0137, P0138, P0156, P0157 or P0158)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG) and turn the tester on.

    3. Select the following menu items: Powertrain / Engine and ECT / DTC.

    4. Read the DTCs.

      Result
      Display (DTC Output) Proceed to
      P0138 or P0158 A
      P0137 or P0157 B
      P0136 or P0156 C

    B

    CHECK FOR EXHAUST GAS LEAKAGE Click here

    C

    READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR) Click here

    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 on (IG) and turn the tester on.

    3. Select the following menu items: Powertrain / Engine and ECT / Data List / A/F Control System / O2S B1S2 or O2S B2S2.

    4. Allow the engine to idle.

    5. Read the Heated Oxygen (HO2) sensor output voltage while idling.

      Result
      HO2 Sensor Output Voltage Proceed to
      More than 1.2 V A
      Less than 1.0 V B

    B

    INSPECT AIR FUEL RATIO SENSOR Click here

    A

  3. INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)


    1. A017CL3E06

      Disconnect the heated oxygen sensor connector.

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

      Standard resistance
      Bank 1
      Tester Connection Condition Specified Condition
      1 (+B) - 3 (E2) Always 10 kΩ or higher
      1 (+B) - 4 (OX1B) Always 10 kΩ or higher
      Bank 2
      Tester Connection Condition Specified Condition
      2 (+B) - 4 (E2) Always 10 kΩ or higher
      2 (+B) - 3 (OX2B) Always 10 kΩ or higher

    3. Reconnect the heated oxygen sensor connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT)


    1. A017DPQE02

      Turn the ignition switch off and wait for 5 minutes.

    2. Disconnect the ECM connectors.

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

      Standard resistance
      Bank 1
      Tester Connection Condition Specified Condition
      B1-1 (HT1B) - B1-18 (OX1B) Always 10 kΩ or higher
      Bank 2
      Tester Connection Condition Specified Condition
      B2-5 (HT2B) - B2-33 (OX2B) Always 10 kΩ or higher

    4. Reconnect the ECM connectors.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here

  5. 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 below 3 mA in this test.


    1. Connect an intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG).

    3. Turn the tester on.

    4. Select the following menu items: Powertrain / Engine and ECT / DTC / Clear.

    5. Clear DTCs.

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


      1. Warm up the engine.

      2. Drive the vehicle at 60 km/h (40 mph) or more for 10 minutes or more.

      3. Stop the vehicle.

      4. Accelerate the vehicle up to 60 km/h (40 mph) or more and then decelerate for 5 seconds or more. Repeat this process at least 3 times.

        A017DV1E06

    7. Select the following menu items: Powertrain / Engine and ECT / Data List / A/F Control System / AFS B1S1 and AFS B2S1.

    8. Read the value of the air fuel ratio sensor current while the fuel-cut operation is performing.

      Standard current
      Less than 3.0 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.

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

    A

    REPLACE HEATED OXYGEN SENSOR Click here

    B

    REPLACE AIR FUEL RATIO SENSOR Click here

  6. READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG) and turn the tester on.

    3. Start the engine.

    4. Select the following menu items: Powertrain / Engine and ECT / Data List / A/F Control System / O2S B1S2 or O2S B1S2.

    5. After warming up the engine, run the engine at an engine speed of 2500 rpm for 3 minutes.

    6. Read the output voltage of the heated oxygen sensor when the engine rpm is suddenly increased.

      Tech Tips

      Quickly accelerate the engine to 4000 rpm 3 times using the accelerator pedal.

      Standard
      Fluctuates between 0.4 V or less and 0.5 V or more.

    NG

    CHECK FOR EXHAUST GAS LEAKAGE Click here

    OK

  7. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine and turn the tester on.

    3. Warm up the engine.

    4. Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.

    5. Change the fuel injection volume using the tester, while monitoring the voltage output of air fuel ratio and heated oxygen sensors 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 1% graduations within the range.

      • The air fuel ratio sensor is displayed as AFS B1S1 or AFS B2S1, and the heated oxygen sensor is displayed as O2S B1S2 or O2S B2S2, on the intelligent tester.

      Result
      Tester Display (Sensor) Voltage Variation Proceed to

      AFS B1S1 (Air fuel ratio)

      AFS B2S1 (Air fuel ratio)

      		 Alternates between more and less than 3.3 V OK

      AFS B1S1 (Air fuel ratio)

      AFS B2S1 (Air fuel ratio)

      		 Remains at more than 3.3 V NG

      AFS B1S1 (Air fuel ratio)

      AFS B2S1 (Air fuel ratio)

      		 Remains at less than 3.3 V NG

      Tech Tips

      A normal heated oxygen sensor voltage (O2S B1S2 or O2S B2S2) 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.

      A017BRRE15

    NG

    REPLACE AIR FUEL RATIO SENSOR Click here

    OK

    CHECK AND REPLACE EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO Click here

  8. CHECK FOR EXHAUST GAS LEAKAGE

    OK
    No gas leakage.

    NG

    REPAIR OR REPLACE EXHAUST GAS LEAKAGE POINT

    OK

  9. INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)


    1. A017CL3E06

      Disconnect the heated oxygen sensor connector.

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

      Standard resistance
      Bank 1
      Tester Connection Condition Specified Condition
      2 (HT1B) - 1 (+B) 20°C (68°F) 11 to 16 Ω
      2 (HT1B) - 3 (E2) Always 10 kΩ or higher
      Bank 2
      Tester Connection Condition Specified Condition
      1 (HT2B) - 2 (+B) 20°C (68°F) 11 to 16 Ω
      1 (HT2B) - 4 (E2) Always 10 kΩ or higher

    3. Reconnect the heated oxygen sensor connector.


    NG

    REPLACE HEATED OXYGEN SENSOR Click here

    OK

  10. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)


    1. A017G4SE05

      Disconnect the heated oxygen sensor connector.

    2. Disconnect the ECM connectors.

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

      Standard resistance (Check for open)
      Bank 1
      Tester Connection Condition Specified Condition
      P1-4 (OX1B) - B1-18 (OX1B) Always Below 1 Ω
      P1-3 (E2) - B1-28 (E2) Always Below 1 Ω
      Bank 2
      Tester Connection Condition Specified Condition
      B38-3 (OX2B) - B2-33 (OX2B) Always Below 1 Ω
      B38-4 (E2) - B1-28 (E2) Always Below 1 Ω
      Standard resistance (Check for short)
      Bank 1
      Tester Connection Condition Specified Condition
      P1-4 (OX1B) or B1-18 (OX1B) - Body ground Always 10 kΩ or higher
      P1-3 (E2) or B1-28 (E2) - Body ground Always 10 kΩ or higher
      Bank 2
      Tester Connection Condition Specified Condition
      B38-3 (OX2B) or B2-33 (OX2B) - Body ground Always 10 kΩ or higher
      B38-4 (E2) or B1-28 (E2) - Body ground Always 10 kΩ or higher

    4. Reconnect the heated oxygen sensor connector.

    5. Reconnect the ECM connectors.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here

  11. REPLACE HEATED OXYGEN SENSOR


    1. Replace the heated oxygen sensor Click here.


    NEXT

  12. PERFORM CONFIRMATION DRIVING PATTERN


    1. Perform confirmation driving pattern.


    NEXT

  13. CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137, P0137, P0156, P0157 OR P0156)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG) and turn the tester on.

    3. Select the following menu items: Powertrain / Engine and ECT / DTC.

    4. Read the DTCs.

      Result
      Display (DTC Output) Proceed to
      P0136 or P0156 A
      No output B

    B

    END

    A

    REPLACE AIR FUEL RATIO SENSOR Click here

  14. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT

  15. PERFORM CONFIRMATION DRIVING PATTERN


    1. Perform confirmation driving pattern.


    NEXT

  16. CHECK WHETHER DTC OUTPUT RECURS (DTC P0136, P0137, P0138, P0156, P0157 OR P0158)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG) and turn the tester on.

    3. Select the following menu items: Powertrain / Engine and ECT / DTC.

    4. Read the DTCs.

      Result
      Display (DTC Output) Proceed to
      P0136, P0137, P0138, P0156, P0157 or P0158 A
      No output B

    B

    END

    A

    REPLACE HEATED OXYGEN SENSOR Click here