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Your fuel-injection system in your Mercedes-Benz includes a component called a Mass AirFlow (MAF) sensor. Like all components in a car, your MAF sensor is subject to failure over time if not frequently serviced.

When your MAF sensor is faulty, your car is subject to symptoms that make driving unenjoyable, wasteful, and potentially harmful for your Mercedes engine health. We’re here to show you the signs of a faulty MAF sensor so you know exactly when it’s time to take your car in for service.

The MAF Sensor

For your Mercedes engine to burn gasoline efficiently, your engine control module relies on the MAF sensor to relay the correct amount of fuel to inject into each cylinder. Through an electrically hot wire, an ambient temperature wire, and a thermometer, the MAF sensor relays the change in temperature recorded from the hot wire as air enters your engine.

The powertrain control module then injects the corresponding amount of fuel into each cylinder to maintain your engine’s ideal fuel-to-air ratio, based on the drop in temperature experienced by the 200°F wire. This is the system that most cars use, including Mercedes-Benz, but this can vary depending on your model.

Over time your MAF sensor can get dirty with oils, grease, and dust kicked up into your car engine from the road. When this happens, air won’t flow properly through your MAF sensor’s components, and your PCM can’t inject the correct amount of fuel into the engine’s cylinders. While this most likely won’t result in total engine failure right away, it will surely lead to it. There are a few signs that your MAF sensor isn’t functioning properly. Let’s take a closer look.

Signs that Your MAF Sensor is Failing

MAF sensor faults all relate to performance issues. While some are more noticeable than others, below are the potential side effects of a dirty or damaged MAF sensor:

• Acceleration Issues: You may notice that when accelerating your car begins to jerk, stutter, and stall as a result of excess fuel being injected into your engine. This can happen at any time, from highway speeds to city cruising. These sudden shifts in momentum can cause accidents when unexpected.
• Fuel-Rich Engine Ratio: As a result of an excess fuel injection caused by faulty MAF sensor readings, a number of issues can result from a rich engine ratio. Things like black exhaust smoke, poor fuel economy, strong odor of gasoline, and rough idling are all signs that your PCM is injecting more fuel than necessary into your engine.
• Engine Start Problems: An additional symptom of a failing MAF sensor is trouble starting and turning your engine over. Not enough fuel in the cylinders makes it difficult for your car to ignite a strong enough combustion This can be also called a fuel-lean engine ratio in comparison to a fuel-rich engine ratio. This is the same reason acceleration is difficult going uphill, since not enough fuel is available to burn.
• Check Engine Lamp: The last of the signs of a possible MAF sensor failure is a check engine warning displayed on your dashboard. This can be for a number of reasons besides a faulty MAF sensor. A trip to your trusted auto shop should be your first stop.

Servicing Your Mercedes-Benz for a Faulty MAF Sensor

Cleaning the wires and intake tubing might be a quick solution for most MAF sensor problems. However, it is always best to bring your Mercedes to a certified mechanic to handle all issues with a faulty MAF sensor. Attempting to solve issues yourself can end up in more problems arising if you damage a component in the injection system while trying to remove the MAF sensor.

For any problems you may have with your Mercedes-Benz, Autowerks is your first choice for repairs. Owned by College Station natives, we have been servicing residents in Brenham, Bryan, Caldwell, Madisonville, Navasota, and College Station, TX for over 45 years.

We provide affordable services for your European automobile with the quality of a full-fledged dealership but the care of a business who wants to earn your trust. We guarantee you’ll be satisfied with our courteous, prompt, and honest certified mechanics. Call today to schedule a service for your Mercedes-Benz, and let our experts solve your troubles.