Mass Airflow Sensor MAF (7/17) [2019 | 2020-2021, B4204T23; B4204T27 | 2020-2022, B4204T28 | 2020-2022, B4204T39]: Description

The mass airflow sensor MAF contains two sensors combined into one component.

• The mass airflow sensor measures how much air mass is being sucked into the engine. The mass airflow sensor is made up of two resistors: a cold resistor and a heated resistor. The heated resistor is heated up to a set temperature above the cold resistor. Both resistors are positioned within the airflow. The mass airflow sensor uses the temperature difference between the resistors to calculate the air mass. The signal output from the mass airflow sensor is a frequency signal with the approximate measured frequency 1 - 10 kHz. The mass airflow sensor sends signals to the Engine Control Module (ECM).
• The intake air temperature sensor measures the temperature of the air coming into the engine. The sensor is a NTC resistor.