BMW 13621307486 Mass Air Flow Sensor

Two types of Mass Air Flow (MAF) sensors are used in the operation of a vehicle. The electro-mechanical vane type sensor consists of an air vane that moves a potentiometer, which calculates the air flow. The fully electronic MAF sensor, on the other hand, has no moving parts and measures the intake air flow electronically. Both sensors provide information to the Engine Control Module (ECM) to adjust the fuel-to-air ratio and control the fuel injectors accordingly. The MAF sensor calculates the intake air volume by using a reference current to heat a thin wire, which is then converted into a voltage measurement. This system allows for precise adjustment of the fuel mixture based on atmospheric conditions. In cars equipped with Automatic Slip Control and Traction (ASC+T), an additional throttle valve is controlled by an electronic throttle actuating motor for traction control purposes. When testing the MAF sensor, it is important to avoid touching the hot wire element or any electronic parts inside and to protect the element from dirt and fluids. The MAF sensor can be checked for faults using diagnostic equipment or by following specific steps, such as checking for a 5 volt signal and monitoring the ohmmeter readings. If the MAF sensor is faulty, the Check Engine light will be activated and a Diagnostic Trouble Code (DTC) will be stored. When removing or installing the MAF sensor, it is important to disconnect the electrical connector, loosen the necessary clamps, and secure the sensor properly.