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Mass Air Flow Meter: Inspection

  1. INSPECT OUTPUT VOLTAGE 
    1. Apply battery voltage across terminals 1 (+B) and 2 (E2G).
    2. Connect the positive (+) tester probe to terminal 3 (VG), and the negative (-) tester probe to terminal 2 (E2G).
    3. Blow air into the MAF meter, and check if the voltage fluctuates.
      Fig 1: Inspecting Output Voltage
      G05843794Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. INSPECT RESISTANCE 
    1. Using an ohmmeter, measure the resistance between terminals 4 (THA) and 5 (E2).
      Fig 2: Inspecting Resistance
      G05843795Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Resistance: 

      12.5 to 16.9 kΩ at -20°C (-4°F) 

      2.19 to 2.67 kΩ at 20°C (68°F) 

      0.50 to 0.68 kΩ at 60°C (140°F) 

  3. INSPECT MASS AIR FLOW METER 
    1. If using a Techstream:
      1. Connect Techstream to the DLC3.
      2. Turn the ignition switch ON (IG)
      3. Turn the tester on.
      4. Enter the following menus:

        Select. Powertrain/Engine and ECT/Data List/MAF.

      5. Blow air into the MAF meter, and check that the air flow value of the CURRENT DATA changes. If operation is not as specified, check the MAF meter as well as the wiring and the ECM
        Fig 3: Inspecting Mass Air Flow Meter
        G04968207Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. If not using a Techstream
      1. Turn the ignition switch to the ON position.
      2. Connect the positive tester probe of the voltmeter to terminal VG of the ECM and the negative tester probe of the voltmeter to terminal E2G of the ECM.
      3. Blow air into the air flow meter, and check if the voltage fluctuates.

        If operation is not as specified, check the MAF meter, the wiring and the ECM.

        Fig 4: Connecting Positive Tester Probe To Terminal VG Of ECM And Negative Tester Probe To Terminal E2G Of ECM
        G04968208Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002