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Home >> Lexus >> 2023 >> ES 300h Base >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (A25A-FXS) - Diagnostic Codes (19 Of 20) >> SFI System >> DTC P2A00-26: O2 Sensor Circuit Range/Performance Bank 1 Sensor 1 Signal Rate of Change Below Threshold [08/2021 - 09/2022] >> Procedure
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DTC P2A00-26: O2 Sensor Circuit Range/Performance Bank 1 Sensor 1 Signal Rate of Change Below Threshold [08/2021 - 09/2022]: Procedure

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00-26) 
    1. Connect the GTS to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the GTS on.
    4. Enter the following menus: Powertrain / Engine / Trouble Codes.
    5. Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      Result Proceed to
      DTC P2A00-26 is output A
      DTC P2A00-26 and other DTCs are output B

      HINT: 

      If any DTCs other than P2A00-26 are output, troubleshoot those DTCs first.

    Result: 

    B 

    GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2021 - 09/2022] 

    Result: 

    A 

    See step  2

  2. PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME FOR A/F SENSOR) 
    1. Connect the GTS to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the GTS on.
    4. Put the engine in Inspection Mode (Maintenance Mode).

      Powertrain > Hybrid Control > Utility 

      Tester Display
      Inspection Mode
    5. Start the engine and warm it up until the engine coolant temperature reaches 80°C (176°F) or higher.
    6. Idle the engine for 5 minutes or more with park (P) selected.
    7. Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor / Data List / Coolant Temperature, A/F (O2) Sensor Current B1S1 and A/F (O2) Sensor Current B1S2.

      Powertrain > Engine > Active Test 

      Active Test Display
      Control the Injection Volume for A/F Sensor
      Data List Display
      Coolant Temperature
      A/F (O2) Sensor Current B1S1
      A/F (O2) Sensor Current B1S2
    8. Perform the Control the Injection Volume for A/F Sensor operation with the engine idling.
    9. Monitor the output values of the air fuel ratio sensor (sensor 1) and air fuel ratio sensor (sensor 2) (A/F (O2) Sensor Current B1S1 and A/F (O2) Sensor Current B1S2) displayed on the GTS.

      HINT: 

      • 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 air fuel ratio sensor (sensor 1) has an output delay of a few seconds and the air fuel ratio sensor (sensor 2) has a maximum output delay of approximately 20 seconds.
      • If the sensor output value does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.
      STANDARD

      GTS Display (Sensor) Injection Volume Status Value
      A/F (O2) Sensor Current B1S1
      (Air fuel ratio (sensor 1))      		 12.5% Rich Below -0.075 mA
      -12.5% Lean More than 0.037 mA
      A/F (O2) Sensor Current B1S2
      (Air fuel ratio (sensor 2))      		 12.5% Rich Below -0.86 mA
      -12.5% Lean More than 0.33 mA

      Result

      Status of A/F (O2) Sensor Current B1S1 Status of A/F (O2) Sensor Current B1S2 Air Fuel Ratio Condition and Air Fuel Ratio Sensor (Sensor 1) Condition Proceed to
      Lean/Rich Lean/Rich Normal A
      Lean Lean Actual air fuel ratio lean B
      Rich Rich Actual air fuel ratio rich
      Lean Lean/Rich Air fuel ratio sensor (sensor 1) malfunction C
      Rich Lean/Rich Air fuel ratio sensor (sensor 1) malfunction
      1. Lean: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor (sensor 1) output current (A/F (O2) Sensor Current B1S1) is consistently more than 0.037 mA, and the air fuel ratio sensor (sensor 2) output current (A/F (O2) Sensor Current B1S2) is consistently more than 0.33 mA.
      2. Rich: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor (sensor 1) output current (A/F (O2) Sensor Current B1S1) is consistently below -0.075 mA, and the air fuel ratio sensor (sensor 2) output current (A/F (O2) Sensor Current B1S2) is consistently below -0.86 mA.
      3. Lean/Rich: During the Control the Injection Volume for A/F Sensor Active Test, the output current of the air fuel ratio sensor (sensor 1) or air fuel ratio sensor (sensor 2) alternate correctly.

      HINT: 

      Refer to "Data List / Active Test" [A/F (O2) Sensor Voltage B1S1, A/F (O2) Sensor Voltage B2S1, A/F (O2) Sensor Current B1S2 and A/F (O2) Sensor Current B2S2].

      Refer to DATA LIST / ACTIVE TEST [08/2021 - 09/2022]

    Result: 

    B 

    See step  7

    Result: 

    C 

    See step  16

    Result: 

    A 

    See step  3

  3. CLEAR DTC 
    1. Connect the GTS to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the GTS on.
    4. Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

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

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  4

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00-26 OR P2A03-26) 
    1. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
    2. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    3. Input the DTC: P2A00-26.
    4. Check the DTC judgment result.

      Result

      Result Proceed to
      NORMAL
      (DTCs are not output)      		 A
      ABNORMAL
      (DTC P2A00-26 is output)      		 B

    Result: 

    A 

    END 

    Result: 

    B 

    See step  5

  5. PERFORM ACTIVE TEST USING GTS (CONTROL THE EGR STEP POSITION) 
    1. Connect the GTS to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the GTS on.
    4. Put the engine in Inspection Mode (Maintenance Mode).

      Powertrain > Hybrid Control > Utility 

      Tester Display
      Inspection Mode
    5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

      HINT: 

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

    6. Enter the following menus: Powertrain / Engine / Active Test / Control the EGR Step Position / Data List / Intake Manifold Absolute Pressure, Coolant Temperature and Engine Independent.

      Powertrain > Engine > Active Test 

      Active Test Display
      Control the EGR Step Position
      Data List Display
      Intake Manifold Absolute Pressure
      Coolant Temperature
      Engine Independent
    7. Confirm that the value of Data List item Engine Independent is "Operate" then check the value of Intake Manifold Absolute Pressure while performing the Active Test.
      NOTE:
      • Make sure that the value of Data List item Engine Independent is "Operate" while performing the Active Test.
      • 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.
      • Do not open the EGR valve 30 steps or more during the Active Test.

      OK

      The value of Intake Manifold Absolute Pressure changes in response to the EGR step position when the value of Engine Independent is "Operate".

      Standard

      - EGR Step Position (Active Test)
      0 Steps 0 to 30 Steps
      Intake Manifold Absolute Pressure
      (Data List)      		 (EGR valve is fully closed) Intake Manifold Absolute Pressure value is at least +10 kPa (1.45 psi) higher than when EGR valve is fully closed

      HINT: 

      • If the value of Data List item Engine Independent is "Not Opr" when the engine is idling, charge control is being performed. Perform the Active Test after charge control is complete ("Operate" is displayed).
      • While performing the Active Test, if the increase in the value of Intake Manifold Absolute Pressure is small, the EGR valve assembly may be malfunctioning.
      • Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of Intake Manifold Absolute Pressure may occur while performing the Active Test. However, the amount that the value of Intake Manifold Absolute Pressure increases will be smaller than normal.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    See step  16

    Result: 

    NG 

    See step  6

  6. INSPECT EGR VALVE ASSEMBLY 
    1. Remove the EGR valve assembly.

      Refer to REMOVAL [08/2021 - 09/2022]

    2. Check if the EGR valve is stuck open.

      OK

      EGR valve is tightly closed.

      HINT: 

      Perform "Inspection After Repair" after replacing the EGR valve assembly.

      Refer to INITIALIZATION [08/2021 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    See step  16

    Result: 

    NG 

    REPLACE EGR VALVE ASSEMBLY. Refer to  REMOVAL [08/2021 - 09/2022] 

  7. INSPECT AIR FUEL RATIO SENSOR (SENSOR 1) (HEATER RESISTANCE) 
    1. Inspect the air fuel ratio sensor (sensor 1).

      Refer to INSPECTION [06/2018 - ]

      HINT: 

      Perform "Inspection After Repair" after replacing the air fuel ratio sensor (sensor 1).

      Refer to INITIALIZATION [08/2021 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE AIR FUEL RATIO SENSOR (SENSOR 1) (SENSOR 1). Refer to  REMOVAL [06/2018 - ] 

    Result: 

    OK 

    See step  8

  8. CHECK INTAKE SYSTEM 
    1. Check the intake system for vacuum leaks.

      Refer to ON-VEHICLE INSPECTION [06/2018 - ]

      OK

      No leaks in the intake system.

      HINT: 

      Perform "Inspection After Repair" after repairing or replacing the intake system.

      Refer to INITIALIZATION [08/2021 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE INTAKE SYSTEM 

    Result: 

    OK 

    See step  9

  9. CHECK FOR EXHAUST GAS LEAK 
    1. Check for exhaust gas leaks.

      OK

      No gas leaks.

      HINT: 

      Perform "Inspection After Repair" after repairing or replacing the exhaust system.

      Refer to INITIALIZATION [08/2021 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE EXHAUST SYSTEM 

    Result: 

    OK 

    See step  10

  10. PERFORM ACTIVE TEST USING GTS (CONTROL THE EGR STEP POSITION) 
    1. Connect the GTS to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the GTS on.
    4. Put the engine in Inspection Mode (Maintenance Mode).

      Powertrain > Hybrid Control > Utility 

      Tester Display
      Inspection Mode
    5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

      HINT: 

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

    6. Enter the following menus: Powertrain / Engine / Active Test / Control the EGR Step Position / Data List / Intake Manifold Absolute Pressure, Coolant Temperature and Engine Independent.

      Powertrain > Engine > Active Test 

      Active Test Display
      Control the EGR Step Position
      Data List Display
      Intake Manifold Absolute Pressure
      Coolant Temperature
      Engine Independent
    7. Confirm that the value of Data List item Engine Independent is "Operate" then check the value of Intake Manifold Absolute Pressure while performing the Active Test.
      NOTE:
      • Make sure that the value of Data List item Engine Independent is "Operate" while performing the Active Test.
      • 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.
      • Do not open the EGR valve 30 steps or more during the Active Test.

      OK

      The value of Intake Manifold Absolute Pressure changes in response to the EGR step position when the value of Engine Independent is "Operate".

      Standard

      - EGR Step Position (Active Test)
      0 Steps 0 to 30 Steps
      Intake Manifold Absolute Pressure
      (Data List)      		 (EGR valve is fully closed) Intake Manifold Absolute Pressure value is at least +10 kPa (1.45 psi) higher than when EGR valve is fully closed

      HINT: 

      • If the value of Data List item Engine Independent is "Not Opr" when the engine is idling, charge control is being performed. Perform the Active Test after charge control is complete ("Operate" is displayed).
      • While performing the Active Test, if the increase in the value of Intake Manifold Absolute Pressure is small, the EGR valve assembly may be malfunctioning.
      • Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of Intake Manifold Absolute Pressure may occur while performing the Active Test. However, the amount that the value of Intake Manifold Absolute Pressure increases will be smaller than normal.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    See step  12

    Result: 

    NG 

    See step  11

  11. INSPECT EGR VALVE ASSEMBLY 
    1. Remove the EGR valve assembly.

      Refer to REMOVAL [08/2021 - 09/2022]

    2. Check if the EGR valve is stuck open.

      OK

      EGR valve is tightly closed.

      HINT: 

      Perform "Inspection After Repair" after replacing the EGR valve assembly.

      Refer to INITIALIZATION [08/2021 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE EGR VALVE ASSEMBLY. Refer to  REMOVAL [08/2021 - 09/2022] 

    Result: 

    OK 

    See step  12

  12. CHECK FUEL PRESSURE (FOR LOW PRESSURE SIDE) 
    1. Check the fuel pressure (for low pressure side).

      Refer to PROCEDURE - Step 2

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  19

    Result: 

    OK 

    See step  13

  13. INSPECT PORT FUEL INJECTOR ASSEMBLY 
    1. Inspect the port fuel injector assembly (whether fuel volume is high or low, and whether injection pattern is poor).

      Refer to INSPECTION [06/2018 - ]

      HINT: 

      Perform "Inspection After Repair" after replacing the port fuel injector assembly.

      Refer to INITIALIZATION [08/2021 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE PORT FUEL INJECTOR ASSEMBLY. Refer to  REMOVAL [08/2021 - 09/2022] 

    Result: 

    OK 

    See step  14

  14. READ VALUE USING GTS (FUEL PRESSURE (HIGH)) 
    1. Connect the GTS to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the GTS on.
    4. Put the engine in Inspection Mode (Maintenance Mode).

      Powertrain > Hybrid Control > Utility 

      Tester Display
      Inspection Mode
    5. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off.
    6. Enter the following menus: Powertrain / Engine / Data List / Engine Speed, Coolant Temperature, Fuel Pressure (High) and Injection Mode.

      Powertrain > Engine > Data List 

      Tester Display
      Engine Speed
      Coolant Temperature
      Fuel Pressure (High)
      Injection Mode
    7. According to the display on the GTS, read the Data List.

      HINT: 

      During charge control, the engine speed is set at idle. Therefore, the engine speed will not increase when the accelerator pedal is depressed. In this case, read the Data List after charge control has completed.

      Standard

      GTS Display Condition Specified Condition
      Fuel Pressure (High)
      • Shift position: P
      • A/C: Off
      • Engine warmed up
      • Engine Speed: 2500 rpm
      • Injection Mode: Direct
      		 3000 to 25000 kPag

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE FUEL SYSTEM (FOR HIGH PRESSURE) 

    Result: 

    OK 

    See step  15

  15. INSPECT DIRECT FUEL INJECTOR ASSEMBLY 
    1. Inspect the direct fuel injector assembly.

      Refer to INSPECTION [06/2018 - ]

      HINT: 

      Perform "Inspection After Repair" after replacing the direct fuel injector assembly.

      Refer to INITIALIZATION [08/2021 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE DIRECT FUEL INJECTOR ASSEMBLY. Refer to  REMOVAL [08/2021 - 09/2022] 

    Result: 

    OK 

    See step  16

  16. REPLACE AIR FUEL RATIO SENSOR (SENSOR 1) 
    1. Replace the air fuel ratio sensor (sensor 1).

      Refer to REMOVAL [06/2018 - ]

      HINT: 

      Perform "Inspection After Repair" after replacing the air fuel ratio sensor (sensor 1).

      Refer to INITIALIZATION [08/2021 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  17

  17. CLEAR DTC 
    1. Connect the GTS to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the GTS on.
    4. Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

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

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  18

  18. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00-26) 
    1. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
    2. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    3. Input the DTC: P2A00-26.
    4. Check the DTC judgment result.

      Result

      Result Proceed to
      ABNORMAL
      (DTC P2A00-26 is output)      		 A
      NORMAL
      (DTCs are not output)      		 B

    Result: 

    A 

    REPLACE ECM. Refer to  REMOVAL [08/2021 - 09/2022] 

    Result: 

    B 

    END 

  19. CHECK FUEL LINE (FOR LOW PRESSURE SIDE) 
    1. Check the fuel lines (for low pressure side) for leaks or blockage.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE). Refer to  REMOVAL [08/2021 - 09/2022] 

    Result: 

    NG 

    REPAIR OR REPLACE FUEL LINE (FOR LOW PRESSURE SIDE) 

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