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MAF Sensor

A Mass (Air) Flow Sensor (MAF) measures the flow rate of air entering an internal combustion engine. The Engine Control Unit (ECU) must know how much air is in the engine to balance and deliver the correct amount of fuel. If the MAF sensor fails, the check engine light will illuminate.

  • It is necessary for the engine control unit or ECU to deliver and balance the correct fuel mass to the engine.
  • It provides the open-loop controller which provides the measured airflow to the ECU, and the oxygen sensors provide closed-loop feedback in order to make corrections to the air mass predicted
  • The mass airflow sensor is used together with an oxygen sensor, wherein the engine's air-fuel mixture ratio can be accurately controlled.

 Information about engine speed and engine load can tell the ECM how much air is entering the engine. Using this information to regulate the fuel feed is called speed-density metering. It is used in fuel injection systems that do not directly measure mass airflow.