Mercedes-Benz AdBlue warning light explained

Many Mercedes-Benz diesel models use AdBlue in their exhaust system as a way to contribute to a cleaner environment with lower emissions.

If your Mercedes-Benz relies on AdBlue, you may encounter a warning light on your dashboard. This simply indicates a low AdBlue level that requires a refill. But what happens if you have refilled the tank and the light is still on?

Discover everything you need to know about Mercedes-Benz AdBlue. We will cover what it is, how to check your fluid levels, and most importantly, how to reset a warning light after a refill.


What is Mercedes-Benz AdBlue?

Diesel and Adblue Fuel Caps

AdBlue assists Mercedes-Benz diesel models in maintaining their impressive fuel efficiency while minimising their environmental footprints. But what exactly is AdBlue, and how does it work to reduce harmful emissions?

Essentially, AdBlue is a colorless liquid solution made from urea and deionised water. Within your Mercedes-Benz diesel's exhaust system, AdBlue plays a vital role in reducing polluting nitrogen oxide (NOx) emissions.

During operation, AdBlue is injected into the exhaust stream after combustion. Through a process called Selective Catalytic Reduction (SCR), AdBlue triggers a chemical reaction that converts harmful NOx pollutants into harmless water vapour and nitrogen gas.

Most new and used Mercedes-Benz diesel models registered after 2015 use AdBlue in an attempt to become more sustainable and tackle traffic pollution.

How to check your Mercedes-Benz AdBlue level

Silver Mercedes-Benz C-Class Side

Owning a Mercedes-Benz diesel equipped with AdBlue technology means keeping an eye on the essential fluid. Thankfully, most models offer a user-friendly way to check the AdBlue level yourself.

The first sign of a low AdBlue level will likely be a warning light on your dashboard. The light's colour usually indicates the amount of urgency to refill your vehicle. A yellow warning light indicates low levels of Adblue (usually around 1,500 to 1,650 miles remaining), whilst red warns of critically low AdBlue levels, requiring an immediate refill.

A number of Mercedes-Benz models also allow you to view the exact AdBlue level through the instrument cluster, often within the "Service" menu or a dedicated "AdBlue" section.

Refer to your car's user manual for specific instructions on navigating your vehicle. Remember, ignoring the AdBlue warning light can impact your car's performance, so it is important to stay on top of refills.

How to reset a Mercedes-Benz AdBlue warning light

AdBlue Warning Light

After refilling your AdBlue tank, you may still see a warning light on your dashboard. Here is how to reset it:

  1. Turn on the ignition. Do not start the engine, just turn the ignition to the "on" position.
  2. Acknowledge the warning. On your steering wheel, you will likely find a button labelled "OK" or similar. Press this button to confirm the AdBlue warning message on the dashboard.
  3. Navigate the menu. Using the buttons on your steering wheel, find the "Menu" selection and press it. Then, scroll down to select the "Settings" option.
  4. Access the AdBlue reset. Within "Settings", look for options related to "Vehicle" or "Service." Once you find these, navigate deeper to find an "AdBlue Reset" function. Select this option.

Following these steps should reset the AdBlue warning light on your Mercedes-Benz. If the light persists after performing these steps, consult your car's user manual or contact a qualified service technician.

Please note that this is a general guide, and the exact steps may vary depending on your specific model. Always refer to your car's user manual for the most accurate instructions.

Where to buy Mercedes-Benz AdBlue

There are various options when it comes to purchasing AdBlue for your Mercedes-Benz model, but it is essential to choose the safest and most convenient option for you.

Mercedes-Benz models do not require any specific type of AdBlue to run properly. However, it is important to get it from a reliable seller to avoid damaging your car’s engine.

Our Stratstone Mercedes-Benz dealerships are a trusted and practical option, and our trained technicians are on hand to carry out an AdBlue tank refill for you.

How to refill AdBlue in a Mercedes-Benz

Fuel Pumps

Just like filling up your Mercedes-Benz' diesel tank, topping up your AdBlue involves locating the filler cap on your Mercedes-Benz. The exact placement of the filler nozzle can vary depending on the model you drive.

To ensure a smooth refill process, we recommend consulting your car's handbook for specific instructions.

Mercedes-Benz servicing, maintenance, and repairs

By understanding AdBlue and how to monitor and reset the warning light, you can ensure your Mercedes-Benz diesel operates efficiently and minimises environmental impact. Remember, routine maintenance is crucial for optimal performance and longevity.

For all your Mercedes-Benz needs, including AdBlue refills and expert servicing, our team of certified technicians is equipped to handle all aspects of your car's care, ensuring a smooth and enjoyable driving experience. Visit your nearest Stratstone Mercedes-Benz retailer to schedule an appointment today.