Air Flow Meter/Sensor: Description and Operation

Mass Air Flow Sensor:

Mass Air Flow Sensor Operation:

PURPOSE
Measure the mass flow of air entering the engine.

LOCATION
On the air cleaner.

OPERATION
The Mass Air Flow (MAF) sensor measure the amount of air which passes trough it in a given amount of time. The Engine Control Module (ECM) uses this information to determine the operating condition of the engine, to control fuel delivery. A large quantity of air movement indicates acceleration, while a small quantity indicates deceleration or idle.



CONSTRUCTION
The MAF sensor consists of a heat resistor, metering duct, straightening net, body and control circuit. 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 controls the heat resistors temperature within a predetermined range of the ambient temperature. As the amount of air entering the sensor increases, then so does the sensors signal current to the ECM. As air flow decreases, then so does the signal current to the ECM.