Mass Airflow (MAF) Sensor
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2002 Lexus SC 430, 2002 Lexus RX 300, 2002 Lexus LX 470, 2002 Lexus LS 430, and 2002 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
MAF sensor measures intake airflow volume. Engine Control Module (ECM) accomplishes this by applying a reference voltage to a hot wire in MAF sensor. As intake air flows across hot wire, resistance value changes, causing reference voltage to change. ECM uses voltage signal to control fuel injection duration and ignition timing. MAF sensor also contains an intake air temperature sensor which is used to measure intake air temperature. See INTAKE AIR TEMPERATURE SENSOR .