LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2024 >> RX 500h >> Repair and Diagnosis >> External Pages >> Different car >> Section 10 (Engine Control System - Diagnostic Codes (10 Of 10), Symptom Tests (1 Of 2) & Circuit Tests (1 Of 2)) >> SFI SYSTEM (for Gasoline Model) >> DTC P2A00-26: O2 Sensor Circuit Range/Performance Bank 1 Sensor 1 Signal Rate of Change Below Threshold [10/2022 - ] >> Procedure

DTC P2A00-26: O2 Sensor Circuit Range/Performance Bank 1 Sensor 1 Signal Rate of Change Below Threshold [10/2022 - ]: Procedure

WARNING: This page is about a different car, the 2025 Lexus RX 350, 2024 Lexus RX 350, and 2023 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00-26) 
    1. Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

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

      HINT: 

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

    Result: 

    A 

    GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [10/2022 - 08/2023]  , or Refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2023 - 10/2024]  , or Refer to  DIAGNOSTIC TROUBLE CODE CHART [10/2024 - ] 

    Result: 

    B 

    See step  2

  2. PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME FOR A/F SENSOR) 

    Pre-procedure1

    • Start the engine and warm it up until the engine coolant temperature reaches 80°C (176°F) or higher.

      Powertrain > Engine > Data List 

      Tester Display
      Coolant Temperature
    • Warm up the air fuel ratio sensors at an engine speed of 2500 rpm for 90 seconds.

      Powertrain > Engine > Data List 

      Tester Display
      Engine Speed
    • Perform the Control the Injection Volume for A/F Sensor operation with the engine idling.

      Powertrain > Engine > Active Test 

      Active Test Display
      Control the Injection Volume for A/F Sensor
      Data List Display
      A/F (O2) Sensor Current B1S1
      A/F (O2) Sensor Current B1S2
    • 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 [10/2022 - 10/2024] , or refer to DATA LIST / ACTIVE TEST [10/2024 - ]

    Post-procedure1

    • None.

    Result: 

    B 

    See step  5

    Result: 

    C 

    See step  12

    Result: 

    A 

    See step  3

  3. CLEAR DTC 

    Pre-procedure1

    • None.
    • Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

      Result

      Proceed to
      NEXT

    Post-procedure1

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

    Result: 

    NEXT 

    See step  4

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00-26) 

    Pre-procedure1

    • Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
    • Input the DTC: P2A00-26.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    • Check the DTC judgment result.

      Result

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

    Post-procedure1

    • None.

    Result: 

    A 

    END 

    Result: 

    B 

    See step  12

  5. INSPECT AIR FUEL RATIO SENSOR (SENSOR 1) (HEATER RESISTANCE) 

    Refer to INSPECTION [10/2022 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE AIR FUEL RATIO SENSOR (SENSOR 1). Refer to  REMOVAL [10/2022 - ] 

    Result: 

    OK 

    See step  6

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

      Refer to PROCEDURE - Step 1

      OK

      No leaks in the intake system.

      HINT: 

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

      Refer to INITIALIZATION [10/2022 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE INTAKE SYSTEM 

    Result: 

    OK 

    See step  7

  7. CHECK FOR EXHAUST GAS LEAK 

    OK

    No gas leaks.

    HINT: 

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

    Refer to INITIALIZATION [10/2022 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPAIR OR REPLACE EXHAUST SYSTEM 

    Result: 

    OK 

    See step  8

  8. CHECK FUEL PRESSURE (LOW PRESSURE SIDE) 

    Refer to PROCEDURE - Step 3

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  15

    Result: 

    OK 

    See step  9

  9. 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 [10/2022 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE PORT FUEL INJECTOR ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

    Result: 

    OK 

    See step  10

  10. READ VALUE USING GTS (FUEL PRESSURE (HIGH)) 

    Pre-procedure1

    • 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.

      Powertrain > Engine > Data List 

      Tester Display
      Coolant Temperature
    • According to the display on the GTS, read the Data List with the following condition.
      • Shift position: P
      • A/C: Off
      • Engine warmed up
      • Engine Speed: 3000 rpm
      • Injection Mode: Direct

      Powertrain > Engine > Data List 

      Tester Display
      Engine Speed
      Fuel Pressure (High)
      Injection Mode

      Result

      Result Proceed to
      The value of Fuel Pressure (High) is between 2000 and 32000 kPag A
      None of the above conditions are met B

    Post-procedure1

    • None.

    Result: 

    B 

    REPAIR OR REPLACE FUEL SYSTEM (FOR HIGH PRESSURE) 

    Result: 

    A 

    See step  11

  11. INSPECT DIRECT FUEL INJECTOR ASSEMBLY 

    Refer to INSPECTION [10/2022 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE DIRECT FUEL INJECTOR ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

    Result: 

    OK 

    See step  12

  12. REPLACE AIR FUEL RATIO SENSOR (SENSOR 1) 

    HINT: 

    Refer to REMOVAL [10/2022 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  13

  13. CLEAR DTC 

    Pre-procedure1

    • None.
    • Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

      Result

      Proceed to
      NEXT

    Post-procedure1

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

    Result: 

    NEXT 

    See step  14

  14. CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00-26) 

    Pre-procedure1

    • Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
    • Input the DTC: P2A00-26.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    • Check the DTC judgment result.

      Result

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

    Post-procedure1

    • None.

    Result: 

    A 

    END 

    Result: 

    B 

    REPLACE ECM. Refer to  REMOVAL [10/2022 - ] 

  15. 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 

    GO TO FUEL PUMP CONTROL CIRCUIT. Refer to  Fuel Pump Control Circuit [10/2022 - ]  

    Result: 

    NG 

    REPAIR OR REPLACE FUEL LINE (FOR LOW PRESSURE SIDE) 

scientia non olet · About LEMON Manuals