Factors Causing Illumination of the Check Engine Light in a Mercedes from Experts in Bellingham
Posted on April 26, 2022 by Keith Cox
The check engine light on your Mercedes dashboard can illuminate for an array of reasons. Being a high-end vehicle, your car will need expert attention when the light illuminates. There are some common scenarios in which your engine light will behave:
- If the check engine light is constantly on, this indicates that something is amiss and needs to be checked out. In this scenario, you might not necessarily notice a change in the performance of your vehicle. However, it is important to get your car inspected to find the root cause.
- The check engine light comes on and turns off at different intervals: In this scenario, you will likely notice changes in performance when the light comes on, and then it seems to resolve. This still is a warning sign that something is malfunctioning.
- Check engine light is on and there are noticeable performance issues: At this point, you may experience engine stalling, rough idling, and a foul smell. The engine performance may be deteriorating as parts are damaged.
- The check engine light blinks while driving: This indicates a major issue with your engine. You should pull over immediately and contact for a tow to our Mercedes service center.
Common Reasons for the Check Engine Light
It is important to note that the fault code that caused the light to turn on is stored in your car’s onboard computer and will be accessed by our mechanics to find the root cause of the problem. Below are the most common reasons for your engine warning light:
- Loose gas cap: This is the most common culprit of all known factors. A loose/faulty gas cap allows vapor to escape into the atmosphere. It can also reduce fuel pressure, reduce fuel economy, and increase harmful emissions.
- Faulty mass airflow sensor: The mass airflow sensor (MAF) determines the mass of air entering your vehicle’s fuel injection engine. It then passes data to the ECU for processing. The information is important for the engine control unit (ECU) to balance and deliver the correct amount of fuel to the engine. When the sensor is defective, normally because of contamination, contact fault at the electrical connections, damaged measuring elements, mechanical damage (vibrations, accident), and measuring element drift, it can cause problems that will result in poor engine performance, poor fuel economy and even severe engine damage hence the illumination of the light.
- Faulty oxygen sensor: The oxygen sensor provides critical air-fuel mixture information to the onboard computer. Because of prolonged exposure to hot temperatures, your oxygen sensor will wear out. A faulty oxygen sensor may lead to inappropriate amounts of fuel entering the engine. You might experience total engine failure when your engine gets too little gas, yet at the same time, your engine will produce so much smoke and odor when the fuel supply is in excess. A faulty oxygen sensor means your vehicle is emitting more pollutants and hence the check engine light will be illuminated.
- Faulty catalytic converter: The catalytic converter is positioned between the engine and the muffler. Its primary purpose is to reduce emissions from the exhaust. Sensors are located before and after the converter. The sensors will trigger an onboard diagnostics trouble code on your computer if there is an anomaly. When this code is triggered, the check engine light will illuminate. Here, the catalytic converter could be faulty. Either it could be clogged with material or just simply worn out and hence not optimally serving its function.
- Spark Plugs: The function of the spark plugs is to create a hot spark that ignites the air and fuel mixture in the cylinder, which facilitates the engine to run. Worn spark plugs or spark plug wires can cause your vehicle’s check engine light to illuminate. Bad spark plugs will cause your engine to misfire, triggering the light. Overlooking this problem may lead to a congested catalytic converter, spoiled ignition coils, or issues with your oxygen sensor.
Keith Cox Autobahn: We are Mercedes Specialists
In the event your check engine light comes on, pay close attention to your vehicle’s performance. Listen for strange sounds, surging and stopping. If there is nothing strange, you can safely drive to a certified garage for diagnostics. Just remember, if the engine light blinks while driving, you are definitely dealing with a major issue and you need to pull over or risk encountering severe engine damage.
If you are in Bellingham, visit us at Keith Cox Autobahn. We are a trusted source for Audi, BMW, Mercedes, Mini, and Volkswagen service and repair work. Our technicians use state-of-the-art machinery and technology to ensure you receive the quality car care you deserve. Call us at (360)-733-2721 or come by our service center at 1814 Ellis Street in Bellingham, WA.