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Airflow Meter

NOTE: Airflow meter may also be referred to as Mass Airflow (MAF) meter.
WARNING: On Prius, read service precautions before proceeding with service procedure. See SERVICE PRECAUTIONS .
  1. Remove airflow meter. See AIRFLOW METER under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
  2. Using ohmmeter, check resistance between terminals E2 and THA on airflow meter. See Fig 1-Fig 4 . Resistance should be within specification in relation to temperature. See AIRFLOW METER RESISTANCE  table. Replace airflow meter if resistance is not within specification.
    AIRFLOW METER RESISTANCE

    Application & Temperature Ohms
    Camry
    -4°F (-20°C) 13,600-18,400
    68°F (20°C) 2210-2690
    140°F (60°C) 493-667
    Camry Solara, Celica & ECHO
    -4°F (-20°C) 13,600-18,400
    68°F (20°C) 2210-2690
    140°F (60°C) 490-670
    Corolla
    -4°F (-20°C) 13,600-18,400
    68°F (20°C) 2200-2700
    140°F (60°C) 500-700
    Highlander
    -4°F (-20°C) 13,600-18,400
    68°F (20°C) 2210-2690
    140°F (60°C) 493-667
    MR2, Prius & RAV4
    -4°F (-20°C) 13,600-18,400
    68°F (20°C) 2210-2690
    140°F (60°C) 490-670
    Tacoma
    -4°F (-20°C) 10,000-20,000
    32°F (0°C) 4000-7000
    68°F (20°C) 2000-3000
    104°F (40°C) 900-1300
    140°F (60°C) 400-700
    176°F (80°C) 200-400
  3. Airflow meter operation should be checked. On Camry and Highlander, go to next step. On Camry Solara, Celica, Corolla, ECHO, MR2, Prius, RAV4 and Tacoma, go to step  5.
  4. Apply battery voltage to +B terminal on airflow meter and battery ground to E2G terminal on airflow meter. See Fig 1 . Connect voltmeter leads to proper terminals on airflow meter. See Fig 1. Apply air into designated area on airflow meter and note voltage reading. See Fig 1. While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate.
  5. Install electrical connector on airflow meter. Connect voltmeter leads to proper terminals on airflow meter with electrical connector installed. See Fig 5-Fig 7 . Turn ignition on. Apply air into designated area on airflow meter and note voltage reading. See Fig 1 and Fig 5-Fig 7 . While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Turn ignition off. Remove voltmeter.
Fig 1: Identifying Airflow Meter Terminals, Air Application Area & Voltmeter Connections (Camry & Highlander)
G00028714Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 2: Testing Airflow Meter Resistance (Camry Solara, Celica, ECHO, MR2, Prius & RAV4)
G99F54408Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 3: Testing Airflow Meter Resistance (Corolla)
G99J54410Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 4: Testing Airflow Meter Resistance (Tacoma)
G99B54412Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 5: Testing Airflow Meter Operation (Camry Solara, Celica, ECHO, MR2, Prius & RAV4)
G99G54409Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 6: Testing Airflow Meter Operation (Corolla)
G99A54411Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 7: Testing Airflow Meter Operation (Tacoma)
G97A06318Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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