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Home >> Lexus >> 2016 >> RC 350 Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (2GR-FSE) - Diagnostic Codes (1 Of 5) >> SFI System >> DTC P0102: Mass Air Flow Circuit Low; DTC P0103: Mass Air Flow Circuit High [09/2014 - 11/2017] >> Procedure
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DTC P0102: Mass Air Flow Circuit Low; DTC P0103: Mass Air Flow Circuit High [09/2014 - 11/2017]: Procedure

  1. READ OUTPUT DTC (DTC P0102 OR P0103) 
    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 and ECT / Trouble Codes.
    5. Read the DTCs.

      Powertrain > Engine > Trouble Codes 

      Result

      Result Proceed to
      DTC P0102 is output A
      DTC P0103 is output B

    Result: 

    B 

    See step  6

    Result: 

    A 

    See step  2

  2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF MASS AIR FLOW METER SUB-ASSEMBLY) 
    GTY514114Courtesy 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
      F38-3 (+B) - Body ground Engine switch on (IG) 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  3

  3. 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
      F38-5 (VG) - F1-25 (VG) Always Below 1 Ω
      F38-4 (E2G) - F1-24 (E2G) Always Below 1 Ω
      F38-5 (VG) or F1-25 (VG) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

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

      Refer to ON-VEHICLE INSPECTION [09/2014 - 11/2017]

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

      Refer to INSPECTION [09/2014 - 11/2017]

    3. Inspect the function of the mass air flow meter sub-assembly.
      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 and ECT / Data List / Primary / MAF.

        Powertrain > Engine > Data List 

        Tester Display
        MAF
      5. Start the engine.
      6. Check that the MAF value changes when the engine is raced.

        OK

        The reading changes.

        HINT: 

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

        Refer to INITIALIZATION [09/2014 - 11/2017]

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ECM. Refer to  REMOVAL [09/2014 - 11/2017] 

    Result: 

    NG 

    REPLACE MASS AIR FLOW METER SUB-ASSEMBLY. Refer to  REMOVAL [09/2014 - 11/2017] 

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      F38-3 (+B) - 2G-2 Always Below 1 Ω
      F38-3 (+B) or 2G-2 - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE SEMICONDUCTOR POWER INTEGRATION ECU. Refer to  REMOVAL [09/2014 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  6. CHECK HARNESS AND CONNECTOR (SENSOR GROUND) 
    1. Disconnect the mass air flow meter sub-assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      F38-4 (E2G) - Body ground Always Below 1 Ω

      HINT: 

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

      Refer to INITIALIZATION [09/2014 - 11/2017]

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MASS AIR FLOW METER SUB-ASSEMBLY. Refer to  REMOVAL [09/2014 - 11/2017] 

    Result: 

    NG 

    See step  7

  7. 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
      F38-4 (E2G) - F1-24 (E2G) Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ECM. Refer to  REMOVAL [09/2014 - 11/2017] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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