MAP/MAF Sensor Function Principles
Situated between the intake manifold and the air filter, the MAF sensor is a vital part of the engine management system and determines the amount of air flowing into the intake system of diesel and petrol combustion engines. Based on the air mass information, the engine control unit is able to balance and deliver the correct fuel quantity to the engine. In diesel engines, the MAF sensor serves mainly to control the exhaust gas recirculation (EGR).
The MAP sensor measures the air pressure by the deformation of a membrane with integrated resistors. The pressure varies depending on the throttle position, engine speed, and turbo operation. The Boost Pressure Sensor, in turn, is used in turbocharged engines and located between the turbocharger and intake manifold.