Signs My Mercedes’ Mass Airflow Sensor Is Going Bad

One of the first signs that your Mercedes’ mass airflow (MAF) sensor is going bad is the check engine light. This light will come on because the MAF sensor sent an error code to the main computer, i.e., the engine control module (ECM). This is just one sign that the mass airflow sensor is on the fritz. Peak Euro lists the other signs of a bad mass airflow sensor below.

Acceleration Trouble

The MAF sensor tracks the airflow into the engine. It reports this information to the ECM. This is so the ECM can adjust the air and fuel in the combustion chamber. If the MAF sensor is incorrect in its readings, you may end up with too much air in the mix and your acceleration will lag.

If there is too much fuel in the mix, your Mercedes’ engine will burn away the excess diesel fuel or gasoline. When this happens, you end up with more exhaust flowing out of the tailpipe than normal. A rich fuel mixture can also be caused by a bad mass airflow sensor.

Engine Hesitation

Going back to too much air, your engine will hesitate even after the acceleration hesitated. You may find it difficult to pick up speed, and you may find it difficult to maintain your speed. Your engine may sputter and struggle to run at the speed you desire.

Engine Surging

Too much fuel causes the opposite effect. When the engine is burning away excess fuel, your Mercedes-Benz will turn into a bucking bronco. It will surge and buck forward even though you are not changing the pressure of your foot on the accelerator.

Hard Starts

A malfunctioning MAF sensor also makes it difficult to get your Mercedes-Benz started. This, again, is because the mixture in the combustion chamber is out of balance. It’s possible that the failing MAF sensor is indirectly causing a reduction of fuel injection.

Idling Problems

You may also notice that your Mercedes-Benz idles more roughly than it normally does. When the engine has a low amount of fuel in it, it will struggle to run. In fact, you may notice the rough idling more than you notice problems when the vehicle is in motion.

Reduced Fuel Economy

Finally, if you keep track of it, you will notice that your fuel economy is reduced by the malfunctioning mass airflow sensor. All of the issues in the combustion chamber discussed above reduce your vehicle’s efficiency and, as such, its fuel economy.



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