Understanding the MAF Sensor
The MAF sensor is an electronic sensor that sends a signal to the engine computer, which then uses the measurements to help calculate fuel delivery and spark timing. In most applications, the MAF sensor utilizes an electrically charged wire to determine the amount of airflow entering the air intake. This wire produces an electrical voltage, based on airflow, and sends it to the engine computer, which then uses the information to adjust spark timing, fuel delivery and spark advance. A fault in the MAF sensor can cause a rough idle, poor fuel economy and possibly even stalling.
The majority of cars built since the early 1980s use a computer system to monitor the various functions of a car. When the computer determines there is a fault in any of the computer controlled sensors or components, it will illuminate the Service Engine Soon or Check Engine light to indicate to the driver that the car requires service. On some cars, the Service Engine Soon light will only illuminate after the same fault has been detected a certain number of times. The MAF sensor is one of the various computer controlled sensors that will cause the Check Engine light to illuminate should a fault be detected.