Mass Airflow Sensor

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: MAF sensor also contains the Intake Air Temperature (IAT) sensor. IAT sensor cannot be serviced separately from the MAF sensor.

The Mass Air Flow (MAF) sensor measures changes in the intake air volume that result from changes in throttle opening and air density. Airflow measurements are used by the PCM in order to determine engine fueling requirements.

The MAF sensor is a hot-wire design. A platinum hot-wire and a thermistor are located in the intake air bypass passage of the MAF sensor housing. See Fig 1 . Temperature of the platinum hot-wire is affected by exposure to air flow and by exposure to air temperature. Platinum hot-wire is maintained at a set temperature by controlling the current flow through the wire. The MAF sensor converts changes in current flow to a voltage signal. The voltage signal from the MAF sensor enables the PCM to detect changes in air density and changes in air volume.

Fig 1: Identifying Mass Air Flow Sensor Components

Courtesy of GENERAL MOTORS CORP.