The air mass meter is an important component in your Mercedes' engine. It measures the amount of air that flows into the engine by cooling a wire that has been heated up. When the wire cools down, the computer reads the temperature change as a signal for airflow. This information, then, is used to generate the correct air-fuel ratio. Being a critical part of engine performance, it is important to know the signs that indicate a failing Mercedes Benz E320 air mass meter. Most cases of air mass meter failure will need replacement, but in some cases, they are still cleanable.
An air mass meter's malfunction is not the only reason why the check engine light or CEL turns on, that's why it is important to do a computer analysis to see if the malfunction is coming from the air mass meter. You have two options for this: you can take it to an auto mechanic to get the car's computer analyzed, or you can do it yourself using a digital auto diagnostics scanner. If you decide to do it yourself and use a diagnostics scanner, check the readout according to the codes found in the reference book that comes with the scanner. If the scanner codes indicate a failed air mass meter, check if it still can be cleaned or repaired or if you need to replace it already.
Although the air mass meter is equipped with a panel filter to prevent the entry of particles, tiny ones still manage to get through and accumulate by the sensor or somewhere else inside the meter. Severe buildup can lead to inaccurate airflow readings, which may lead to engine malfunction. The air mass meter is quite accessible with an open hood, so you can check if it is already too dirty with many particles on the inside of the intake tube. And if you take off the bolts and wiring harness, you can manage to open it and expose the sensor-essentially, the wires. If after effectively cleaning the wires up with a MAF cleaner, thoroughly drying the air mass meter, and carefully reinstalling it, the car's engine performance becomes normal, there is no need to get a new one yet.