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Home >> Lexus >> 2015 >> GS 350 F Sport, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Diagnostic Codes (1 Of 4) >> SFI System >> DTC P0102: Mass or Volume Air Flow Circuit Low Input; DTC P0103: Mass or Volume Air Flow Circuit High Input [09/2014 - 10/2015] >> Procedure
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DTC P0102: Mass or Volume Air Flow Circuit Low Input; DTC P0103: Mass or Volume Air Flow Circuit High Input [09/2014 - 10/2015]: Procedure

  1. READ DTC OUTPUT 
    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.

      Result

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

    Result: 

    B 

    See step  5

    Result: 

    A 

    See step  2

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE) 
    1. Disconnect the mass air flow meter connector.
      GTY533659Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      F39-3 (+B) - Body ground Engine switch on (IG) 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Mass Air Flow Meter)
    4. Reconnect the mass air flow meter connector.

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - NO. 1 INTEGRATION RELAY) 

    Result: 

    OK 

    See step  3

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

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      F39-5 (VG) - F1-25 (VG) Always Below 1 Ω
      F39-4 (E2G) - F1-24 (E2G) Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      F39-5 (VG) or F1-25 (VG) - Body ground Always 10 kΩ or higher
    4. Reconnect the mass air flow meter connector.
    5. Reconnect the ECM connector.

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - ECM) 

    Result: 

    OK 

    See step  4

  4. INSPECT MASS AIR FLOW METER 
    1. Perform On-vehicle Inspection (Refer to ON-VEHICLE INSPECTION [09/2014 - 10/2015] ).
    2. Perform Inspection (Refer to INSPECTION [09/2014 - 10/2015] ).
    3. Inspect the function of the mass air flow meter.
      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 / MAF.
      5. Start the engine.
      6. Check that the reading of 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 (Refer to INITIALIZATION [09/2014 - 10/2015] ).

    Result: 

    OK 

    REPLACE ECM 

    (Refer to REMOVAL [09/2014 - 10/2015] )

    Result: 

    NG 

    REPLACE MASS AIR FLOW METER 

    (Refer to REMOVAL [09/2014 - 10/2015] )

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

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      F39-4 (E2G) - Body ground Always Below 1 Ω
    3. Reconnect the mass air flow meter connector.

      HINT: 

      Perform "Inspection After Repair" after replacing the mass air flow meter (Refer to INITIALIZATION [09/2014 - 10/2015] ).

    Result: 

    OK 

    REPLACE MASS AIR FLOW METER 

    (Refer to REMOVAL [09/2014 - 10/2015] )

    Result: 

    NG 

    See step  6

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

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      F39-4 (E2G) - F1-24 (E2G) Always Below 1 Ω
    4. Reconnect the mass air flow meter connector.
    5. Reconnect the ECM connector.

    Result: 

    OK 

    REPLACE ECM 

    (Refer to REMOVAL [09/2014 - 10/2015] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - ECM) 

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