LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2017 >> IS 300 F Sport >> Repair and Diagnosis >> External Pages >> Different car >> Section 37 (Engine Control System (8AR-FTS) - Diagnostic Codes (05 Of 14)) >> SFI System >> DTC P0234-00: Turbocharger/Supercharger "A" Overboost Condition [08/2015 - 09/2022] >> Procedure

DTC P0234-00: Turbocharger/Supercharger "A" Overboost Condition [08/2015 - 09/2022]: Procedure

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2024 Lexus IS 300, 2023 Lexus IS 300, 2022 Lexus IS 300, 2021 Lexus IS 300, and 2020 Lexus IS 300. 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. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Trouble Codes.
    5. Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

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

      HINT: 

      If any DTCs other than P0234-00 are output, troubleshoot those DTCs first.

    Result: 

    GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2015 - 10/2016]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [10/2016 - 10/2017]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [10/2017 - 09/2018]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [09/2018 - 09/2019]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [09/2019 - 09/2020]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [09/2020 - 11/2021]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [11/2021 - 09/2022] 

    Result: 

    See step  2

  2. READ VALUE USING TECHSTREAM (ATMOSPHERIC PRESSURE) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Data List / Atmospheric Pressure.

      Powertrain > Engine > Data List 

      Tester Display
      Atmospheric Pressure
    5. 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.
    6. 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: 

    REPLACE ECM. Refer to  REMOVAL [08/2015 - ] 

    Result: 

    See step  3

  3. READ VALUE USING TECHSTREAM (INTAKE AIR TEMPERATURE) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Data List / Intake Air Temperature.

      Powertrain > Engine > Data List 

      Tester Display
      Intake Air Temperature
    5. According to the display on the Techstream, read the Data List.

      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: 

    See step  16

    Result: 

    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 [08/2015 - 09/2020] , or refer to ON-VEHICLE INSPECTION [09/2020 - ]

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

      Refer to INSPECTION [08/2015 - ]

    3. Inspect the operation of the mass air flow meter sub-assembly.
      1. Connect the Techstream to the DLC3.
      2. Start the engine.
      3. Turn the Techstream on.
      4. Enter the following menus: Powertrain / Engine / Data List / Engine Speed, Mass Air Flow Sensor and Coolant Temperature.

        Powertrain > Engine > Data List 

        Tester Display
        Engine Speed
        Mass Air Flow Sensor
        Coolant Temperature
      5. Allow the engine to idle until Coolant Temperature reaches 75°C (167°F) or higher.
      6. Read Mass Air Flow Sensor while maintaining an engine speed of 3000 rpm.

        Standard

        Techstream Display Condition Specified Condition
        Mass Air Flow Sensor Engine warmed up
        Shift lever position: P
        A/C: Off
        Engine Speed: 3000 rpm
        Between 6.0 gm/sec and 18.0 gm/sec

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  13

    Result: 

    OK 

    See step  5

  5. INSPECT NO. 2 TURBO PRESSURE SENSOR 
    1. Inspect the No. 2 turbo pressure sensor.

      Refer to PROCEDURE - Step 1

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  11

    Result: 

    OK 

    See step  6

  6. INSPECT WASTE GATE VALVE (TURBINE HOUSING WITH VALVE SUB-ASSEMBLY) 
    1. Inspect the waste gate valve.

      Refer to PROCEDURE - Step 1

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE TURBINE HOUSING WITH VALVE SUB-ASSEMBLY. Refer to  REMOVAL [08/2015 - ] 

    Result: 

    OK 

    See step  7

  7. INSPECT VACUUM REGULATING VALVE ASSEMBLY 
    1. Inspect the vacuum regulating valve assembly.

      Refer to INSPECTION [08/2015 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE VACUUM REGULATING VALVE ASSEMBLY. Refer to  REMOVAL [08/2015 - ] 

    Result: 

    OK 

    See step  8

  8. INSPECT WASTE GATE VALVE ACTUATOR WITH BRACKET ASSEMBLY 
    1. Inspect the waste gate valve actuator with bracket assembly.

      Refer to INSPECTION [08/2015 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE WASTE GATE VALVE ACTUATOR WITH BRACKET ASSEMBLY. Refer to  REMOVAL [08/2015 - ] 

    Result: 

    OK 

    See step  9

  9. CHECK HARNESS AND CONNECTOR (VACUUM REGULATING VALVE ASSEMBLY - ECM) 
    1. Disconnect the vacuum regulating valve assembly connector.
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      F99-1 (+) - F78-37 (WGV+) Always Below 1 Ω
      F99-2 (-) - F78-36 (WGV-) Always Below 1 Ω
      F99-1 (+) or F78-37 (WGV+) - Body ground and other terminals Always 10 kΩ or higher
      F99-2 (-) or F78-36 (WGV-) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  10

  10. CHECK WHETHER DTC OUTPUT RECURS (DTC P0234-00) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Clear the DTCs.

      Powertrain > Engine > Clear DTCs 

    5. Turn the engine switch off and wait for at least 30 seconds.
    6. Start the engine and warm it up.
    7. Turn the Techstream on.
    8. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
    9. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

      Powertrain > Engine > Utility 

      Tester Display
      All Readiness
    10. Input the DTC: P0234-00.
    11. Check the DTC judgment result.

      Result

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

    Result: 

    END 

    Result: 

    REPLACE ECM. Refer to  REMOVAL [08/2015 - ] 

  11. CHECK TERMINAL VOLTAGE (POWER SOURCE OF NO. 2 TURBO PRESSURE SENSOR) 
    GTY643313Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Front view of wire harness connector
    (to No. 2 Turbo Pressure Sensor)
    1. Disconnect the No. 2 turbo pressure sensor connector.
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      F81-3 (VC) - F81-1 (E2) Engine switch on (IG) 4.75 to 5.25 V
      F81-2 (PTA) - F81-1 (E2) Engine switch on (IG) 3.0 to 5.25 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

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

    Result: 

    NG 

    See step  12

  12. CHECK HARNESS AND CONNECTOR (NO. 2 TURBO PRESSURE SENSOR - ECM) 
    1. Disconnect the No. 2 turbo pressure sensor connector.
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      F81-3 (VC) - F78-140 (VPTA) Always Below 1 Ω
      F81-1 (E2) - F78-139 (EPTA) Always Below 1 Ω
      F81-2 (PTA) - F78-108 (PTA) Always Below 1 Ω
      F81-3 (VC) or F78-140 (VPTA) - Body ground and other terminals Always 10 kΩ or higher
      F81-2 (PTA) or F78-108 (PTA) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ECM. Refer to  REMOVAL [08/2015 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  13. CHECK TERMINAL VOLTAGE (POWER SOURCE OF MASS AIR FLOW METER SUB-ASSEMBLY) 
    GTY662198Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Front view of wire harness connector
    (to Mass Air Flow Meter Sub-assembly)
    1. Disconnect the mass air flow meter sub-assembly connector.
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      F40-3 (+B) - Body ground Engine switch on (IG) 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  15

    Result: 

    OK 

    See step  14

  14. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 
    1. Disconnect the mass air flow meter sub-assembly connector.
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      F40-5 (VG) - F78-92 (VG) Always Below 1 Ω
      F40-4 (E2G) - F78-91 (E2G) Always Below 1 Ω
      F40-5 (VG) or F78-92 (VG) - Body ground and other terminals Always 10 kΩ or higher

      HINT: 

      Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.

      Refer to INITIALIZATION [08/2015 - 09/2018] , or refer to INITIALIZATION [09/2018 - 09/2019] , or refer to INITIALIZATION [09/2019 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MASS AIR FLOW METER SUB-ASSEMBLY. Refer to  REMOVAL [08/2015 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  15. CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - MASS AIR FLOW METER SUB-ASSEMBLY) 
    1. Disconnect the semiconductor pwr integration ECU connector.
    2. Disconnect the mass air flow meter sub-assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      2G-1 - F40-3 (+B) Always Below 1 Ω
      2G-1 or F40-3 (+B) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE SEMICONDUCTOR POWER INTEGRATION ECU. Refer to  REMOVAL [04/2013 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  16. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY (INTAKE AIR TEMPERATURE SENSOR) 
    1. Inspect the mass air flow meter sub-assembly (intake air temperature sensor).

      Refer to INSPECTION [08/2015 - ]

      HINT: 

      Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.

      Refer to INITIALIZATION [08/2015 - 09/2018] , or refer to INITIALIZATION [09/2018 - 09/2019] , or refer to INITIALIZATION [09/2019 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE MASS AIR FLOW METER SUB-ASSEMBLY. Refer to  REMOVAL [08/2015 - ] 

    Result: 

    OK 

    See step  17

  17. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 
    1. Disconnect the mass air flow meter sub-assembly connector.
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      F40-1 (THA) - F78-94 (THA) Always Below 1 Ω
      F40-2 (E2) - F78-93 (ETHA) Always Below 1 Ω
      F40-1 (THA) or F78-94 (THA) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ECM. Refer to  REMOVAL [08/2015 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR