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Home >> Lexus >> 2009 >> IS 250 AWD >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control System (DTCS P0010 - P0368) >> SFI System >> DTC P0100: Mass or Volume Air Flow Circuit; 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 P0100: Mass or Volume Air Flow Circuit; DTC P0102: Mass or Volume Air Flow Circuit Low Input; DTC P0103: Mass or Volume Air Flow Circuit High Input: Procedure

  1. READ VALUE USING MASS AIR FLOW METER (MAF) 
    1. Connect Techstream to the DLC3.
    2. Turn the engine switch on (IG) (do not run the engine).
    3. Enter the following menus: Powertrain / Engine / Data List / All Data / MAF.
    4. Wait 30 seconds, and read the values on the tester.
      NOTE:
      • Perform the inspection with the vehicle indoors and on a level surface.
      • Perform the inspection of the MAF meter while it is installed to the air cleaner case (installed to the vehicle).
      • During the test, do not use an exhaust air duct on the exhaust tail pipe assembly.

        Result

        Mass Air Flow Rate (gm/sec) Proceed to
        0.0 A
        0.36 or more B
        More than 0.0 and less than 0.36 C

    C → CHECK FOR INTERMITTENT PROBLEMS 

    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. INSPECT ECM (VG VOLTAGE) 
    1. Start the engine.
      Fig 2: Identifying ECM Connector
      GTY124531Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      HINT: 

      The transmission gear selector lever should be in the neutral position and the A/C switch should be turned OFF.

      Standard voltage

      Tester Connection Condition Specified Condition
      VG (E5-27) - E2G (E5-26) Engine idling 0.5 to 3.0 V

    OK → REPLACE ECM 

    NG: Go to next step 

  4. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
    1. Disconnect the E29 MAF meter connector.
      Fig 3: Identifying Connector Terminals
      GTY145506Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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 → REPLACE MASS AIR FLOW METER 

  5. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - INTEGRATION RELAY) 
    1. Inspect the EFI No. 2 fuse.
      Fig 4: Identifying Connector Terminals
      GTY145518Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Remove the EFI No. 2 fuse from the engine room No. 2 relay block.
      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 J/B and 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. INSPECT ECM (SENSOR GROUND) 
    1. Measure the resistance according to the value(s) in the table below.
      Fig 5: Identifying ECM Connector
      GTY124386Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard resistance

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

    NG → REPLACE ECM 

    OK: Go to next step 

  7. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
    1. Disconnect the E29 MAF meter connector.
      Fig 6: Identifying Connector Terminals
      GTY145506Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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 → REPLACE MASS AIR FLOW METER 

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