Why Is My Check Engine Light On?

5 Reasons Why Your Check Engine Light Might Be On

Mercedes-Benz Check Engine light- Atlanta, Georgia- Austrian Motors


Most car owners dread the moment when the check engine light pops up on the dashboard. This is even scarier when we are on the highway or driving long distances. The truth is, the pop-up Check Engine Light can be attributed to a number of issues.

Most often, the Check Engine Light doesn’t mean an emergency or big repair for your Mercedes-Benz. Any certified mechanic will be able to diagnose the problem rather easily. At Austrian Motors, we have mechanics with more than 30 years of experience with a variety of Mercedes Models. Even if you don’t live in Atlanta, there are many qualified places that you can go to get assistance with Check Engine Light Issues. 

Click Here for your Mercedes Benz Maintenance Booklet Provided by MBUSA. 

Most modern-day Mercedes-Benz have an onboard diagnostic system that has a variety of codes identifying the particular issue that has caused the light to come on. Austrian Motors is online with Mercedes-Benz USA  and uses the star diagnostic tool to identify the problem. 

Let’s take a closer look at the most common issues.

Mercedes-Benz Check Engine light- Atlanta, Georgia- Austrian Motors

1. Loose or Faulty Gas Cap

The gas cap is the most common cause of your Check Engine Light flipping on. When the cap is loose or cracked, it allows fuel vapor to escape and can mess up the whole fuel system. This increases emissions and reduces gas mileage. When your system indicates that your gas cap is faulty, pull over and tighten it. Examine the cap for any cracks or worn out edges. Continue driving for about 20 minutes and monitor if the engine light goes off. A typical gas cap costs a few dollars. A loose gas cap may not be risky, but it ultimately leads to lower gas mileage.

2. Faulty Oxygen Sensor

This piece monitors the unburdened oxygen from your Mercedes Benz exhaust and controls how much fuel is being burned. A faulty sensor can’t provide the right data, therefore, causing a decrease in gas mileage. Most Mercedes automobiles have between 2 and 4 oxygen sensors. The code will tell the mechanic which one needs to be replaced. When a sensor becomes faulty, it is usually covered with too much oil ash and loses its ability to change the oxygen and fuel mixture. A faulty oxygen sensor can lead to a burst catalytic converter, which can be a very expensive repair.

Mercedes-Benz Check Engine light- Atlanta, Georgia- Austrian Motors

3. Faulty Mass Airflow Sensor

This gadget tells the car computer to add the necessary amount of fuel based on the air coming through to the car engine. That’s why, when the sensor is faulty, the emissions will increase, the gas mileage will decrease, and the car may stall. The mass airflow sensor usually fails when the air filter is not replaced or when it wears out.

4. Faulty Spark Plugs and Wires

Another reason the check engine light might pop on is faulty spark plugs and wires. The spark plug seals the combustion chamber and provides the gap for initiating combustion in your engine. When they are failing, they begin to misfire. This is often marked by a little jolt when you start accelerating. Older spark plugs can be replaced after 25-30,000 miles, while the newer ones can be replaced after 100, 000 miles. Still, plugs fail over time, and there is little you can do to prevent it.

5. Malfunctioning Catalytic Converter

The work of a catalytic converter is to reduce exhaust gasses. It converts carbon monoxide and other toxic substances in fuel into harmless compounds. If it’s faulty or failing, the gas mileage reduces significantly. Most catalytic converters stay in top shape with regular maintenance. However, they can become damaged because of rusty spark plugs, broken oxygen sensors, etc. When the converter stops functioning properly, harmful gasses will pass out through the exhaust into the environment. When a catalytic converter fully deteriorates, the time has come to replace it.

The National Council of Car Care now provides a Car Care Guide for various automobiles. Follow the link to sign up.

Mercedes-Benz Check Engine light- Atlanta, Georgia- Austrian Motors

We want you to remain safe. This is why Austrian Motors offers 50 point inspections – absolutely free. Don’t hesitate to Contact Us Today and like our Facebook Page for offers and tips on how & when to maintain your Mercedes-Benz. 

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