Air Flow Meter/Sensor: Description and Operation
MASS AIR FLOW (MAF) SENSORMass Air Flow (MAF) Sensor:
The Mass Air Flow (MAF) sensor consists of a heat resistor element (1), a metering duct (2), an air straightening screen (3), a body and control circuit board (4). This MAF sensor is of the thermal control type. The heat resistor is cooled off by the air entering the MAF sensor. The control circuit maintains the heat resistor temperature within a predetermined range. When the amount of air entering the sensor increases, the signal created by the sensor and sent to the PCM, also increases. When the air flow decreases so does the signal current to the PCM. The MAF sensor is located in the air intake duct between the throttle body and the air cleaner.
The Mass Air Flow (MAF) sensor measures the amount of air which passes through it in a given amount of time. The Powertrain Control Module (PCM) uses this information in order to determine the operating requirements of the engine and control fuel delivery. A large quantity of air movement indicates acceleration, while a small quantity indicates deceleration or idle.