LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2024 >> RX 500h >> Repair and Diagnosis >> External Pages >> Different car >> Section 116 (Engine Control System - Diagnostic Codes (04 Of 10)) >> SFI SYSTEM (for Gasoline Model) >> DTC P0234-00: Turbocharger/Supercharger "A" Overboost Condition [10/2022 - ] >> Procedure

DTC P0234-00: Turbocharger/Supercharger "A" Overboost Condition [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 P0234-00) 
    1. Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      Result Proceed to
      P0234-00 and other DTCs are output A
      P0234-00 is output B

      HINT: 

      If any DTCs other than P0234-00 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. READ VALUE USING GTS (ATMOSPHERIC PRESSURE) 
    1. Check the value of Data List item.

      Powertrain > Engine > Data List 

      Tester Display
      Atmospheric Pressure
    2. Using the following table, determine the normal atmospheric pressure for the current altitude and temperature.
      GTY518158Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      • Standard atmospheric pressure is approximately 101 kPa(abs) (14.65 psi(abs)).
      • For every 100 m (328 ft.) increase in altitude, atmospheric pressure drops by approximately 1 kPa (0.15 psi). This varies depending on the weather.
    3. Compare the value of Atmospheric Pressure with the normal atmospheric pressure in the table.

      Result

      Result Proceed to
      Other than below A
      Difference between value of Atmospheric Pressure and normal atmospheric pressure is 10 kPa (1.45 psi) or higher B

    Result: 

    B 

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

    Result: 

    A 

    See step  3

  3. READ VALUE USING GTS (INTAKE AIR TEMPERATURE) 
    1. According to the display on the GTS, read the Data List.

      Powertrain > Engine > Data List 

      Tester Display
      Intake Air Temperature

      Result

      Result Proceed to
      Difference between value of Intake Air Temperature and actual ambient air temperature is 10°C (18°F) or higher A
      Other than above B

    Result: 

    B 

    See step  15

    Result: 

    A 

    See step  4

  4. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY 
    1. Inspect the mass air flow meter sub-assembly, referring to On-vehicle Inspection for Mass Air Flow Meter.

      Refer to ON-VEHICLE INSPECTION [10/2022 - ]

    2. Inspect the mass air flow meter sub-assembly, referring to Inspection for Mass Air Flow Meter.

      Refer to INSPECTION [10/2022 - ]

    3. Inspect the operation of the mass air flow meter sub-assembly.
      1. Start the engine.
      2. Allow the engine to idle until Coolant Temperature reaches 75°C (167°F) or higher.

        Powertrain > Engine > Data List 

        Tester Display
        Coolant Temperature
      3. Read Mass Air Flow Sensor while maintaining an engine speed of 3000 rpm.

        Powertrain > Engine > Data List 

        Tester Display
        Engine Speed
        Mass Air Flow Sensor

        Standard

        GTS Display Condition Specified Condition
        Mass Air Flow Sensor Engine warmed up
        Shift lever position: P
        A/C: Off
        Engine Speed: 3000 rpm        		 Between 5 and 15 gm/sec

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  12

    Result: 

    OK 

    See step  5

  5. INSPECT NO. 2 TURBO PRESSURE SENSOR 

    Refer to ON-VEHICLE INSPECTION [10/2022 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    See step  10

    Result: 

    OK 

    See step  6

  6. INSPECT VACUUM REGULATING VALVE ASSEMBLY 

    Refer to INSPECTION [10/2022 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE VACUUM REGULATING VALVE ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (VACUUM REGULATING VALVE ASSEMBLY - ECM) 

    Pre-procedure1

    • Disconnect the vacuum regulating valve assembly connector.
    • Disconnect the ECM connector.
    • Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      B42-1 (+) - B27-20 (WGV+) Always Below 1 Ω Ω
      B42-2 (-) - B27-21 (WGV-) Always Below 1 Ω Ω
      B42-1 (+) or B27-20 (WGV+) - Body ground and other terminals Always 10 kΩ or higher kΩ
      B42-2 (-) or B27-21 (WGV-) - Body ground and other terminals Always 10 kΩ or higher kΩ

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None.

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  8

  8. 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  9

  9. CHECK WHETHER DTC OUTPUT RECURS (DTC P0234-00) 

    Pre-procedure1

    • Start the engine and warm it up.
    • Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    • Check the DTC judgment result.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    • Input the DTC: P0234-00.

      Result

      Result Proceed to
      NORMAL
      (DTCs are not output)      		 A
      ABNORMAL
      (DTC P0234-00 is output)      		 B

    Post-procedure1

    • None.

    Result: 

    A 

    END 

    Result: 

    B 

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

  10. CHECK TERMINAL VOLTAGE (POWER SOURCE OF NO. 2 TURBO PRESSURE SENSOR) 

    Pre-procedure1

    • Disconnect the No. 2 turbo pressure sensor connector.
    • Turn the ignition switch to ON.
    • Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition Result
      B44-3 (VC) - B44-2 (E2) Ignition switch ON 4.5 to 5.5 V V
      B44-1 (PTA) - B44-2 (E2) Ignition switch ON 3.0 to 5.0 V V

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None.

    Result: 

    OK 

    REPLACE NO. 2 TURBO PRESSURE SENSOR. Refer to  PROCEDURE - Step 3 

    Result: 

    NG 

    See step  11

  11. CHECK HARNESS AND CONNECTOR (NO. 2 TURBO PRESSURE SENSOR - ECM) 

    Pre-procedure1

    • Disconnect the No. 2 turbo pressure sensor connector.
    • Disconnect the ECM connector.
    • Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      B44-3 (VC) - B27-102 (VPTA) Always Below 1 Ω Ω
      B44-2 (E2) - B27-125 (EPTA) Always Below 1 Ω Ω
      B44-1 (PTA) - B27-126 (PTA) Always Below 1 Ω Ω
      B44-3 (VC) or B27-102 (VPTA) - Body ground and other terminals Always 10 kΩ or higher kΩ
      B44-1 (PTA) or B27-126 (PTA) - Body ground and other terminals Always 10 kΩ or higher kΩ

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None.

    Result: 

    OK 

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

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  12. CHECK TERMINAL VOLTAGE (POWER SOURCE OF MASS AIR FLOW METER SUB-ASSEMBLY) 

    Pre-procedure1

    • Disconnect the mass air flow meter sub-assembly connector.
    • Turn the ignition switch to ON.
    • Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition Result
      B14-3 (VCC) - B14-2 (E2G) Ignition switch ON 4.8 to 5.2 V V
      B14-1 (FG) - B14-2 (E2G) Ignition switch ON 4.8 to 5.2 V V

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None.

    Result: 

    NG 

    See step  14

    Result: 

    OK 

    See step  13

  13. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY 

    Refer to ON-VEHICLE INSPECTION [10/2022 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    OK 

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

    Result: 

    NG 

    REPLACE MASS AIR FLOW METER SUB-ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

  14. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 

    Pre-procedure1

    • Disconnect the mass air flow meter sub-assembly connector.
    • Disconnect the ECM connector.
    • Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      B14-3 (VCC) - B27-73 (VCVG) Always Below 1 Ω Ω
      B14-1 (FG) - B27-75 (VG) Always Below 1 Ω Ω
      B14-2 (E2G) - B27-74 (E2G) Always Below 1 Ω Ω
      B14-3 (VCC) or B27-73 (VCVG) - Body ground and other terminals Always 10 kΩ or higher kΩ
      B14-1 (FG) or B27-75 (VG) - Body ground and other terminals Always 10 kΩ or higher kΩ
      B14-2 (E2G) or B27-74 (E2G) - Body ground and other terminals Always 10 kΩ or higher kΩ

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None.

    Result: 

    OK 

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

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  15. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY (INTAKE AIR TEMPERATURE SENSOR) 

    Refer to INSPECTION [10/2022 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE MASS AIR FLOW METER SUB-ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

    Result: 

    OK 

    See step  16

  16. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 

    Pre-procedure1

    • Disconnect the mass air flow meter sub-assembly connector.
    • Disconnect the ECM connector.
    • Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      B14-4 (THA) - B27-76 (THA) Always Below 1 Ω Ω
      B14-2 (E2G) - B27-74 (E2G) Always Below 1 Ω Ω
      B14-4 (THA) or B27-76 (THA) - Body ground and other terminals Always 10 kΩ or higher kΩ

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None.

    Result: 

    OK 

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

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

scientia non olet · About LEMON Manuals