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Home >> Lexus >> 2010 >> IS 250 AWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (Diagnostic Codes (P0010-P015D) >> SFI System >> DTC P0102: Mass or Volume Air Flow Circuit Low Input; DTC P0103: Mass or Volume Air Flow Circuit High Input >> 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: Procedure

  1. READ DTC OUTPUT 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG) (do not run the engine).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Trouble Codes.
    5. Read the DTCs.

      Result

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

    B → See step   6 

    A: Go to next step 

  2. INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE) 
    1. Disconnect the E29 Mass Air Flow (MAF) meter connector.
      Fig 1: Identifying MAF Meter Connector Terminals
      GTY144746Courtesy 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 Specified Condition
      +B (E29-3) - Body ground 9 to 14 V
    4. Reconnect the MAF meter connector.

    NG → See step   5 

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
    1. Disconnect the E29 MAF meter connector.
    2. Disconnect the E5 ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open)

      Tester Connection Specified Condition
      VG (E29-5) - VG (E5-27) Below 1 Ω
      E2G (E29-4) - E2G (E5-26) Below 1 Ω

      Standard resistance (Check for short)

      Tester Connection Specified Condition
      VG (E29-5) or VG (E5-27) - Body ground 10 kΩ or higher
    4. Reconnect the MAF meter connector.
    5. Reconnect the ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. INSPECT MASS AIR FLOW METER 
    1. Perform On-vehicle Inspection . Refer to ON-VEHICLE INSPECTION .
      Fig 2: Identifying Mass Air Flow Meter
      GTY288460Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Inspect the function of the mass air flow meter.
      1. Remove the mass air flow meter with the connector connected.
      2. Connect the Techstream to the DLC3.
      3. Turn the engine switch on (IG).
      4. Turn the Techstream on.
      5. Enter the following menus: Powertrain / Engine / Data List / MAF.
      6. Blow air into the mass air flow meter and check that the intake air amount reading changes.

        OK

        The reading changes.

    NG → REPLACE MASS AIR FLOW METER 

    OK → See step   8 

  5. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - INTEGRATION RELAY) 
    1. Inspect the EFI No. 2 fuse.
      1. Remove the EFI No. 2 fuse from the engine room R/B No. 2.
      2. Check the EFI No. 2 fuse resistance.

        Standard resistance

        Below 1 Ω

      3. Reinstall the EFI No. 2 fuse.
    2. Disconnect the E29 MAF meter connector.
    3. Remove the integration relay from the engine room R/B No. 2.
    4. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open)

      Tester Connection Specified Condition
      +B (E29-3) - 2A-8 Below 1 Ω

      Standard resistance (Check for short)

      Tester Connection Specified Condition
      +B (E29-3) or 2A-8 - Body ground 10 kΩ or higher
    5. Reconnect the MAF meter connector.
    6. Reinstall the integration relay.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → CHECK ECM POWER SOURCE CIRCUIT 

  6. CHECK HARNESS AND CONNECTOR (SENSOR GROUND) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      Tester Connection Specified Condition
      E2G (E5-26) - Body ground Below 1 Ω

    NG → See step   7 

    OK → REPLACE MASS AIR FLOW METER 

  7. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
    1. Disconnect the E29 MAF meter connector.
    2. Disconnect the E5 ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      Tester Connection Specified Condition
      E2G (E29-4) - E2G (E5-26) Below 1 Ω
    4. Reconnect the MAF meter connector.
    5. Reconnect the ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   8 

  8. REPLACE ECM. Refer to  REMOVAL