Mercedes Radar Sensors Dirty – How to Fix

If you own a Mercedes, one thing that keeps you safe on the road is its radar sensors. When there are problems with these sensors, their indicator light will appear on your dash. In this article, I’ll discuss Mercedes Radar Sensors Dirty – how to fix them.

If you see the words “Radar Sensors Dirty” on the dash of your Mercedes, it means that your vehicle cannot receive a strong signal from the sensors. Perhaps dirt has already formed in them. Cleaning the sensors will restore their ability to send clear signals.

You can use a soft brush or clean cloth dipped in soapy water to clean the dirt accumulated in the sensors. Wash the sensors the way you wash your car’s glass windows, but do it more gently so you won’t scratch the protective covers of the camera lenses.

Read on to learn more about the message “Radar Sensors Dirty’ on your Mercedes dashboard, its meaning, and how to fix it.

Mercedes Radar Sensors Dirty – How to Fix

mercedes radar sensors dirty

If you see the message “Radar Sensors Dirty” on your Mercedes, it is due to the accumulated dirt on the sensors. This dirt is usually a buildup of road debris, dust, or bird droppings left untouched and allowed to harden.

When these sensors are dirty, the signals they will send to your car computer will be unclear, if they can send data at all. By cleaning the dirt, you will restore the ability of these sensors to deliver clear signals to your car’s ECU.

You can use a soft brush or a clean cloth soaked in soapy water to clean the lens debris. Be careful in cleaning the protective covering of the sensors because you can damage their lenses easily. You can also use compressed air to clean the sensors.

Due to their exposed location on your vehicle, the sensors mounted on your Mercedes Benz bumper are prone to dirt and debris formation. They will be the ones that will not be able to send strong signals to your car’s computer. So, inspect them regularly to ensure that they are always dirt-free.

If the “Radar Sensors Dirty” message keeps showing up on your dash, and you have already removed the accumulated dirt on them, something else must trigger it. You have to check the sensor or its wiring for possible damage.

What Is the Importance of a Mercedes Radar Sensor?

1. Front Bumper Sensors Ensures That You Have Enough Distance from Other Vehicles

Mercedes vehicles have front bumper sensors that measure the best distance you need with the car in front and your speed relative to other vehicles around you.

With these sensors, you are sure that you’ll always have enough distance from other vehicles. They can also take over your brakes and pull away your car if necessary.

These radar sensors are typically behind the brand emblems or car bumpers. This way, they could operate and perform as designed.

2. Can Detect the Doppler Effect or the Frequency Wave Variations

These sensors can detect the Doppler Effect or the frequency wave variations. This means they can calculate the speed of an object or vehicle’s speed and its direction. They use this information to warn distance and automatically decelerate or stop the car.

The sensors of your Mercedes use radio waves to detect nearby objects and then compute the distance between them according to the time it takes for the waves to come back.

3. Work with Other Vehicles’ Safety Features

Radar sensors usually work with other safety features of your vehicle. They are part of the lane departure warning, collision avoidance, and adaptive cruise control.

The sensors on your Mercedes must not only be clean at all times. You must also protect them from road damage from rocks, sand, rocks, and small pebbles. If you run over these objects at high speeds, they can fly toward your vehicle and damage the sensors in your front bumper.

4. Systems That Use Radar Sensors

Mercedes-Benz uses radar sensors in the following systems:

  • Collision Avoidance
  • Automatic Emergency Braking
  • Blind Spot Detection
  • Adaptive Cruise Control

In other words, these sensors are parts of several safety features of Mercedes Benz vehicles. They ensure that your safety is assured every time you drive your car. So, you need to ensure they are always in tip-top condition.

How Do You Clean Your Radar Sensors?

mercedes radar sensors dirty message

Gentle and careful are two words that you need to observe when cleaning your Mercedes’ radar sensors. Never use strong chemicals in removing dirt. Only use clean water, a cloth, a soft brush, and plain liquid soap. Clean the sensors using circular motions.

What are the safest ways to remove debris from dirty sensors? Here are some tips:

1. Clean the Bumper Sensors

The bumper sensors are located in your Mercedes’ front and rear bumpers. They are part of the parking assist system of the Parktonic feature of your vehicle:

  • Remove the loose dirt using a soft brush to clean these sensors,
  • Blow the area around the sensor using compressed air, and
  • Follow up with gentle wipes using a dry microfiber cloth.

2. Use a Soft Brush to Clean the Front and Rear Cameras

Your Mercedes has front cameras located on the front, usually below the vehicle’s emblem. The rear camera is behind the license plate at the other end of the car.

The Mercedes’ 360-degree View Camera System – a surround-view camera system uses these cameras. You can use a soft brush to remove the debris and a microfiber cloth to wipe away the remaining dirt.

3. Clean the Side View Mirror Cameras

The side view mirror cameras are on the side mirrors of your Mercedes, one for the left view mirror and one for the right. They are part of the Blind Spot Assist System of the vehicle. These sensors also help you to be aware of your blind spots.

You need to clean the side view mirrors so their cameras and sensors will have a clear view of your blind spots.

4. Use a Microfiber Cloth for the Grill Sensor

On the front of your Mercedes is a sensor just behind the grill. It must be free of dirt, as well as ice and snow. Use compressed air or a dry and soft microfiber cloth to clean this sensor. The same trick can remove snow or ice around the sensor.

5. Use Compressed air or a Soft Brush to Clean the Distance Collision Sensors

Your Mercedes uses a collision avoidance system to prevent you from colliding with another vehicle. In doing its job, this system also uses radar sensors. These sensors are at the front and rear parts of your Mercedes.

To clean these sensors, use compressed air or a soft brush to remove the accumulated debris. Then follow up by wiping the sensor area using a dry microfiber cloth.

6. Rearview Camera Sensor

The rearview camera is on the windshield behind the rearview mirror. This camera also has a front radar sensor. This adaptive cruise control system is an integral part of the Distronic Plus feature of Mercedes Benz vehicles.

The front radar is also part of the Pre-Safe Brake feature of Mercedes Benz vehicles, a forward collision warning system. Use a window cleaner to remove accumulated dust or dirt on the radar’s sensors.

Again, what does radar sensor dirty mean on Mercedes? Mercedes radar sensors and cameras can accumulate dirt over time. This will cause Distronic Plus autonomous cruise control and other radar systems to malfunction.

How to Safely Clean Radar Sensors

There are other safe and practical ways to clean radar sensors. Here are some suggestions to help you remove the dirt on these sensors:

1. Use a Soft Brush to Remove Snow

In removing snow from the radar sensors, use a soft brush. You should be gentle and careful while chipping the snow or ice away. Using rough and sudden movements will damage or shift the sensors, especially the ones mounted on the grille and the vehicle’s bumper.

2. Use a Clean Cloth to Remove Dirt and Debris

Road dirt and debris are some of the unavoidable things that will accumulate on the sensors of your Mercedes Benz. If you allow these foreign matters to get on the sensors, they will cause them to malfunction.

Use a soft brush or a clean cloth soaked in soapy water to clean the sensors. Then brush or wipe the camera just as you use to wipe the glass windows of your Mercedes. Just be careful so that you won’t damage the sensitive sensors of the cameras.

How to Fix Radar Sensors?

mercedes radar sensor dirty warning

Dirt and debris are not the only things that can cause radar sensors to fail. They can also develop issues that can cause them to be ineffective. If a radar sensor becomes defective, only a qualified car tech can repair or replace it.

How to Determine Whether You Have a Defective Radar Sensor?

If you still get the same “Radar Sensors Dirty” message after cleaning it, then it must have an underlying issue you must check.

Take the Mercedes to the Dealer or a Qualified Car Tech

Radar sensors are delicate instruments. An ordinary DIYer does not have the knowledge and training to fix sensor problems. If you notice that the radar sensors are still unable to function after cleaning them, you must take your Mercedes to the dealer.

The Mercedes dealer will have qualified car techs that can handle and fix whatever issues your radar sensors are experiencing. Fixing and replacing defective radar sensors is very complicated. A car tech needs the proper diagnostic and repair tools to resolve the issue.

How Often Should I Clean the Radar Sensors?

It depends on where you usually drive your Mercedes Benz. If your usual drives take you to places with dust and pollen, you must clean the sensors more often than once a month. But cleaning will be enough if you usually drive on dirt-free roads once a month.

Ensure to keep up with the inspection and cleaning of the radar sensors. You must do it regularly. If you don’t, they will get dirty and make them ineffective in doing their job. This means your road safety is compromised each time you drive.

If dirt and debris accumulate on the sensors for a long time, they can be permanently damaged. When that happens, you will be forced to pay more to replace them.

In Closing

The “Mercedes Radar Sensors Dirty” message on your dash indicates that your car cannot receive clear signals from the sensors.

Typically, this is due to the accumulated dirt in the sensors. You need to clean these sensors so they can again send strong signals to your car’s computer.

A soft brush or cloth soaked in soapy water will clean the dirt. Just wash the sensors the way you wash the glasses on your Mercedes. Do it gently and carefully so you won’t damage the covers of the camera lenses.