Mass Airflow Sensor
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2002 Mercury Sable, 2002 Mercury Mountaineer, 2002 Mercury Grand Marquis, 2002 Mercury Cougar, and 2002 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
Mass Airflow (MAF) Sensor is located between Air Cleaner and Throttle Body or inside Air Cleaner Assembly.- MAF sensors use a hot wire sensing element to measure amount of air entering the engine.
- Air passing over the hot wire causes it to cool.
- The hot wire is maintained at 392°F (200°C) greater than ambient temperature, as measured by a constant cold wire. See Fig 1.
- The current required to maintain hot wire operating temperature is proportional to the intake air mass flow.
- MAF sensor outputs an analog voltage signal to PCM proportional to intake air mass.
- PCM uses this signal to calculate fuel injector pulse width in order to provide the desired air/fuel ratio.
- On some applications, MAF sensor input is used in determining transmission Electronic Pressure Control (EPC), shift and Torque Converter Clutch (TCC) scheduling.
- Cougar 2.0L, Escort 2.0L 4V, Econoline, Escape, Explorer, Focus, Mountaineer, Sable, Taurus and Windstar applications use MAF sensors that have Integrated By-Pass Technology (IBT) with an integrated Intake Air Temperature (IAT) sensor.