This calculation helps keep the air to fuel ratio at the optimal level. The PCM uses the airflow signal to calculate how much fuel to inject.

The more air that flows over the wire, the more electric current is needed to keep it hot.Īn electronic chip installed inside the airflow sensor translates the electric current into a digital signal and sends it to the engine computer, also known as a PCM. When you hit the gas, the throttle opens, allowing more air to flow over the hot wire. A small amount of air flows around the hot wire when the engine is idling, so it takes a low electric current to keep the wire hot. A temperature sensor that is installed close to the hot wire measures the temperature of the air near the hot wire. A hot-wire mass airflow sensor has a small, electrically-heated wire. Modern cars use a hot-wire type of airflow sensor. The mass airflow sensor increases the efficiency of your engine, resulting in optimized performance and enhanced fuel economy. Functions of a Mass Airflow SensorĪ mass airflow sensor for a BMW measures the oxygen flowing to your engine for the perfect air-to-fuel ratio. This article will help you understand the different functions of a mass airflow sensor, the problems that can arise with a faulty sensor, and how to fix it.

This knowledge, along with precautionary care, will help keep your BMW’s engine running efficiently for the lifespan of your vehicle. Knowing the functions of a BMW’s mass airflow sensor will not only help you better understand how your car’s engine runs, but will also help you identify quickly when you’re dealing with a faulty airflow sensor.

E46 mass air flow sensor problems