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)

DESCRIPTION

Tech Tips

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

In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a three-way catalytic converter is used. For the most efficient use of the three-way catalytic converter, the air fuel ratio must be precisely controlled so that it is always close to the stoichiometric air fuel level. For the purpose of 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 is 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) met for 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 0.59 V

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

  • 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 leaks from exhaust system

P0137

P0157

  • Low voltage (open):


    • During active air fuel ratio control, following conditions (a) and (b) met for 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

  • 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)

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

  • Gas leaks from exhaust system

P0138

P0158

  • High voltage (short):


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

    • (a) Heated oxygen sensor voltage output more than 0.59 V

    • (b) Target air fuel ratio lean

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

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

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

  • ECM

CONFIRMATION DRIVING PATTERN

A017F1CE67

  1. Connect the intelligent tester to the DLC3.

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

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

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

  5. Turn the ignition switch on (IG) and turn the tester on [A].

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

  7. With the transmission in 4th gear or higher, drive the vehicle at 60 to 120 km/h (37 to 75 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 / Pending.

  9. Read the pending DTC [D].

    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, P0138, P0156, P0157 or P0158.

  12. Check the DTC judgment result.

    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 ABNORMAL, the system has a malfunction.

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

    • If the judgment result shows INCOMPLETE or UNKNOWN, perform step [C] again.

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

  14. Check the DTC judgment result.

    Tech Tips


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

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

WIRING DIAGRAM

A017GBTE01

INSPECTION PROCEDURE

Tech Tips

Malfunctioning areas can be identified by performing the Control the Injection Volume for A/F Sensor function provided in the Active Test. The Control the Injection Volume for A/F 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 A/F Sensor operation using the intelligent tester.


  1. Connect the intelligent tester to the DLC3.

  2. Start the engine.

  3. Turn the tester on.

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

  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 in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume).

  7. Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 or AFS Voltage B2S1 and O2S B1S2 or O2S B2S2) displayed on the intelligent tester.

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 25%.

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

Tester Display Injection Volume Status Voltage

AFS Voltage B1S1 or AFS Voltage B2S1

(Air fuel ratio sensor)

 +25% Rich Less than 3.1 V
-12.5% Lean More than 3.4 V

O2S B1S2 or O2S B2S2

(Heated oxygen sensor)

 +25% Rich More than 0.55 V
-12.5% 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.

Case

Air Fuel Ratio Sensor (Sensor 1)

Output Voltage

Heated Oxygen Sensor (Sensor 2)

Output Voltage

 Main Suspected Trouble Area
1 A017EWCE08 A017ES4E01 -
2 A017EP5E03 A017ES4E01

  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor circuit
3 A017EWCE08 A017EP5E03

  • Heated oxygen sensor

  • Heated oxygen sensor heater

  • Heated oxygen sensor circuit
4 A017EP5E03 A017EP5E03

  • Fuel pressure

  • Gas leakage from exhaust system

    (Air fuel ratio extremely lean or rich)

Tech Tips


  • 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 or OX2B wire from the ECM connector is short-circuited to the +B wire, DTC P0136 or P0156 may be set.

  • Bank 1 refers to the bank that includes the No. 1 cylinder*.

    *: The No. 1 cylinder is the cylinder which is farthest from the transmission.

  • Bank 2 refers to the bank that does not include the No. 1 cylinder.

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

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

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).

    3. Turn the tester on.

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

    5. Read the DTCs.

      Result
      Result Proceed to
      P0138 or P0158 A
      P0137 or P0157 B
      P0136 or P0156 C
      P0136, P0137, P0138, P0156, P0157 or P0158 and other DTCs are output D

    B

    CHECK FOR EXHAUST GAS LEAK Click here

    C

    PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE INJECTION VOLUME) Click here

    D

    GO TO DTC CHART 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).

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / O2S B1S2 or O2S B2S2.

    5. Start the engine and allow the engine to idle.

    6. Read the heated oxygen sensor output voltage while idling.

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

    B

    PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE INJECTION VOLUME) Click here

    A

  3. INSPECT HEATED OXYGEN SENSOR (CHECK FOR SHORT)


    1. A017CL3E24
      Text in Illustration
      *1 Bank 1
      *2 Bank 2
      *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
      Bank 1
      Tester Connection Condition Specified Condition
      1 (+B) - 3 (E2) Always 10 kΩ or higher
      1 (+B) - 4 (OX1B)
      Bank 2
      Tester Connection Condition Specified Condition
      2 (+B) - 4 (E2) Always 10 kΩ or higher
      2 (+B) - 3 (OX2B)

    3. Reconnect the heated oxygen sensor connector.


    NG

    REPLACE HEATED OXYGEN SENSOR Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (CHECK FOR SHORT)


    1. Turn the ignition switch off and wait for 5 minutes or more.

    2. Disconnect the ECM connector.

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

      Standard resistance
      Bank 1
      Tester Connection Condition Specified Condition
      B47-12 (HT1B) - B50-2 (OX1B) Always 10 kΩ or higher
      Bank 2
      Tester Connection Condition Specified Condition
      B47-13 (HT2B) - B50-4 (OX2B) Always 10 kΩ or higher

    4. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here

  5. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE INJECTION VOLUME)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG).

    3. Turn the tester on.

    4. Start the engine and warm it up.

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume / All Data / AFS Voltage B1S1, AFS Voltage B2S1, O2S B1S2 and O2S B2S2.

    6. Change the fuel injection volume using the tester, and monitor 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 fine graduations within the range.

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

      Result
      Tester Display Voltage Variation Proceed to
      AFS Voltage B1S1 or AFS Voltage B2S1 (Air fuel ratio) Alternates between more and less than 3.3 V OK
      Remains at more than 3.3 V NG
      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.

      A017CG6E10

    NG

    REPLACE AIR FUEL RATIO SENSOR Click here

    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. When the sensor is normal, the sensor current will be below 3.0 mA in this test.


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs.

    5. Warm up the engine.

    6. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / AFS Current B1S1 and AFS Current B2S1.

    7. Drive the vehicle according to the drive pattern listed below.


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

      2. Stop the vehicle.

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

        A017DV1E24

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

      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.


    OK

    REPLACE HEATED OXYGEN SENSOR Click here

    NG

    REPLACE AIR FUEL RATIO SENSOR Click here

  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 / All Data / O2S B1S2 or O2S B2S2.

    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 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 higher.

    NG

    CHECK FOR EXHAUST GAS LEAK Click here

    OK

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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG).

    3. Turn the tester on.

    4. Start the engine and warm it up.

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume / AFS Voltage B1S1, AFS Voltage B2S1, O2S B1S2 and O2S B2S2.

    6. Change the fuel injection volume using the tester, and monitor 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 fine graduations within the range.

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

      Result
      Tester Display Voltage Variation Proceed to
      AFS Voltage B1S1 or AFS Voltage B2S1 (Air fuel ratio sensor) Alternates between more and less than 3.3 V OK
      Remains at more than 3.3 V NG
      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.

      A017CG6E10

    NG

    REPLACE AIR FUEL RATIO SENSOR Click here

    OK

    CHECK ENGINE TO DETERMINE CAUSE OF EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO Click here

  9. CHECK FOR EXHAUST GAS LEAK


    1. Check for exhaust gas leaks from the exhaust manifold sub-assembly and exhaust pipes.

      OK
      No gas leaks.

    NG

    REPAIR OR REPLACE EXHAUST GAS LEAK POINT

    OK

  10. INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)


    1. A017CL3E23
      Text in Illustration
      *1 Bank 1
      *2 Bank 2
      *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
      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

  11. 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)
      Bank 1
      Tester Connection Condition Specified Condition
      P1-2 (HT1B) - B47-12 (HT1B) Always Below 1 Ω
      P1-4 (OX1B) - B50-2 (OX1B)
      P1-3 (E2) - B50-1 (EX1B)
      Bank 2
      Tester Connection Condition Specified Condition
      B38-1 (HT2B) - B47-13 (HT2B) Always Below 1 Ω
      B38-3 (OX2B) - B50-4 (OX2B)
      B38-4 (E2) - B50-3 (EX2B)
      Standard resistance (Check for short)
      Bank 1
      Tester Connection Condition Specified Condition
      P1-2 (HT1B) or B47-12 (HT1B) - Body ground Always 10 kΩ or higher
      P1-4 (OX1B) or B50-2 (OX1B) - Body ground
      Bank 2
      Tester Connection Condition Specified Condition
      B38-1 (HT2B) or B47-13 (HT2B) - Body ground Always 10 kΩ or higher
      B38-3 (OX2B) or B50-4 (OX2B) - Body ground

    4. Reconnect the heated oxygen sensor connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. REPLACE HEATED OXYGEN SENSOR


    1. Replace the heated oxygen sensor Click here.


    NEXT

  13. PERFORM CONFIRMATION DRIVING PATTERN


    1. Refer to the confirmation driving pattern for P0136, P0137, P0138, P0156, P0157 and P0158.


    NEXT

  14. 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).

    3. Turn the tester on.

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

    5. Input DTC: P0136, P0137, P0138, P0156, P0157 or P0158.

      Check the STATUS is NORMAL. If DTC Monitor is INCOMPLETE, perform the drive pattern again but increase the vehicle speed.

      Result
      Result Proceed to

      NORMAL

      (DTC is not output)

      		 A

      ABNORMAL

      (DTC P0136, P0137, P0138, P0156, P0157 or P0158 is output)

      		 B

    B

    REPLACE AIR FUEL RATIO SENSOR Click here

    A

    END

  15. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT

  16. PERFORM CONFIRMATION DRIVING PATTERN


    1. Refer to the Confirmation Driving Pattern.


    NEXT

  17. 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).

    3. Turn the tester on.

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

    5. Input DTCs: P0136, P0137, P0138, P0156, P0157 or P0158.

      Check the STATUS is NORMAL. If DTC Monitor is INCOMPLETE, perform the drive pattern again but increase the vehicle speed.

      Result
      Result Proceed to

      NORMAL

      (DTC is not output)

      		 A

      ABNORMAL

      (DTC P0136, P0137, P0138, P0156, P0157 or P0158 is output)

      		 B

    B

    REPLACE HEATED OXYGEN SENSOR Click here

    A

    END