Mercedes Benz Air Suspension Troubleshooting Guide Airmatic Visit Workshop

Experiencing one of the following problems:

• The vehicle is too low. Visit workshop. Warning on Instrument Cluster
• Airmatic Malfunction Warning on the dashboard.
• AIRMATIC VISIT WORKSHOP!
• AIRMATIC – STOP, CAR TOO LOW!
• Mercedes-Benz is sagging in front or back.
• Mercedes-Benz lowered to the ground, all four wheels.

Whether you decide to repair the air suspension yourself or have a mechanic do the work,  read this troubleshooting guide first to know what to expect. Otherwise, you may pay thousands for AIRmatic repairs you don’t need.

Driving a car with air or hydraulic suspension is a dream come true. This system is often called AIRmatic, airlift, air ride, or hydraulic Active Body Control (ABC) suspension. How many cars can you change the suspension settings from comfort to sport with a button? Raise the vehicle a few centimeters in just a few seconds. Now there are plenty of aftermarket airlift conversion kits, but AIRMatic suspension is factory installed on several Mercedes-Benz models. 

Learn how to troubleshoot Mercedes-Benz Air Suspension Problems. 

You decide to buy a Mercedes-Benz, an S-Class, CLS-Class, R-Class, CL-Class, or E-Class. One day you hear of other Mercedes-Benz owners having suspension problems. The next day you start having air suspension problems yourself. Your Mercedes-Benz drops to the ground, and you may even end up towing your car because it is no longer drivable. Now your dreams are replaced with nightmares.

You take your Mercedes-Benz for a diagnosis and get quoted thousands of dollars for air suspension repair. Even worse, only a few select shops know how to fix them. Suppose you are a new owner or mechanic that hasn’t worked on air suspension before. We will guide you through the steps to troubleshoot some of the most common air suspension problems yourself. If you are having issues with the air suspension on your Mercedes-Benz, this troubleshooting guide is for you. You will be surprised when you realize that the air suspension is not that complex.

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A brief overview of the air suspension

The Air Suspension Control Unit controls the suspension on Mercedes-Benz cars equipped with air suspension (N51). The driver can select the driving mode, switching between Comfort and Sport modes. The vehicle level is continually monitored and readjusted whenever there is a difference of more than +/- 20 mm. The suspension will also adapt to the road conditions and the driving style. When the vehicle reaches over 40 mph, the car lowers so that the center of gravity is closer to the ground, improving handling, cornering,  reducing drag, vehicle lift, and rollover risk. This sophisticated system makes you feel like you are floating while riding a Mercedes-Benz until the airlift suspension fails.

First, let’s look at some of the warning signs and symptoms of airmatic suspension problems. On the instrument cluster, you will get two messages. The first is the Air Suspension Failure, Visit Workshop, and the second is the more critical, often shown in red: STOP VEHICLE TOO LOW. 

“AIRMATIC VISIT WORKSHOP!” message on the instrument cluster.

This is typically an electrical fault. You will need an OBD II scanner, such as the YOUCANIC full system scanner, to read the fault codes.

Once you scan the car, you may get fault codes. For example, you will get C1324-001 or C1325-001, which means the solenoid valves in assembly Y53 ( rear axle damping valve unit) present a communication or fault. There could also be a discontinuity problem with any of the air suspension components. This will challenge us to track down without a scanner.

If you get the AIRMATIC Visit Workshop message, your car may still drive but do get it checked out as soon as possible. If the vehicle drops over the next few days, the air suspension may not work to airlift the car.

“AIRMATIC STOP, CAR TOO LOW!” 

This message may be scary. Don’t panic! Note that the car, in most cases, will drop too much, and you will not be able to drive it. Unfortunately, if the air suspension collapses, the car will not be drivable.

What are the most common failures?

A summary of the most common problems with Mercedes-Benz air suspension systems and DIY solutions is provided in the next section:

• The air suspension compressor Failed (Easy DIY repair, Average cost of $200). The air suspension compressor does just that, generating compressed air. It fills up all the air struts, and it can fail. They either seize up, fail to produce the required pressure, or the brushes inside them wear out. In the next section, we will show you how to check if the air suspension compressor is the problem. Sometimes it could be just a $5 faulty relay that may prevent the air suspension compressor from running. 

• Failed Air Strut The air struts leaking is a very common problem. They develop a leak at the mastic at the top of the strut. Below we show you how to test your air struts for leaks. When the seal in the strut degrades, it no longer provides the isolation required, and a leak starts. If a significant leak has developed, you may hear a hissing sound from the wheel housing area. The whole front or rear of the car will drop down, even when only one of the struts is defective. The vehicle will drop more on one side, typically on the side of the leaking air strut.

• Leaking lines The lines that supply the compressed air to the strut can also develop cracks, and eventually, air may leak.

• Faulty relay or Blown Fuse The air suspension compressor relay is known to fail. It could either not engage the air suspension compressor at all or, even worse, keep it engaged longer than required. It can get damaged if the air suspension compressor is kept engaged for too long. There is a chance of a blown fuse for the air compressor pump. You can replace the Fuse with a new one, but if it keeps blowing, you have another issue, usually pointing at the air compressor pump/motor. For example, the Mercedes-Benz S-Class W220 has an air compressor relay and fuse 32 on the fuse box on the passenger side of the engine compartment. Here is a picture that shows where they are located.

• Valve block leaking The main problem with the valve block is that the solenoid valves may leak air back to the compressor or the central air reservoir. This can cause the vehicle not to maintain the ride height required. If you need help troubleshooting the airmatic valve assembly, watch this video. 

• The level sensor is faulty. They are located at the rear and front suspension. The air suspension control unit may no longer recognize the car’s height when they stop working. Your Mercedes-Benz will greet you with a warning message on the dash related to the airmatic failure. The car height may be correct, and the car still rides fine; it’s just that the computer doesn’t know that.

• Brass valves at the top of the strut. It was leaking due to the metal on the metal fitting between the brass valve and the strut connection.

Air Suspension Troubleshooting

In the following video, you will learn how to use a Autel MaxiDAS DS708 to diagnose Mercedes-Benz air suspension problems.

 

Faulty Relay or Blown Fuse for air suspension compressor

One of the first items you should inspect is the air suspension / airmatic relay in the main fuse box in the engine compartment. Also, check the Fuse for the air suspension compressor. On the Mercedes-Benz S-Class, the fuse box containing the air suspension compressor relay and the Fuse is located on the engine’s right (passenger side). Look at the 40 AMP fuse F32, and ensure it is not blown. If the Fuse keeps on blowing, this typically points to air suspension compressor issues. Find the Fuse and relay that are for the air suspension.

The following video will show you how to check the relay on a Mercedes-Benz W220 S-Class (S430, S500, S600, S55 AMG, and CL500, CL600). Procedures are similar for other Mercedes-Benz with air suspension, but the location of the relay and Fuse may change.

In this S-Class W220, the air compressor motor /pump is protected by Fuse 32, which is a MaxiFuse 40 Amp. Here is what a good fuse should look like.

 

 

You can purchase a new relay and eliminate the possibility of the relay being the problem. The relay that is known to be reliable is Multi-Purpose Relay for Air Pump Suspension 0027219 by Hella.

How do you test if the air suspension compressor is working?

Typically when the air suspension compressor quits working, the whole car may lower to the ground and fail to raise. You press the button to raise the vehicle, and nothing happens. If the air suspension compressor works as designed, you will hear the compressor engage and run for several seconds.

Do you hear the air suspension compressor kick in at all?

If not, we need to do further troubleshooting. How can you check if the air suspension compressor is not working/engaging?

Check the voltage of the air compressor.

• Locate the air suspension compressor. It is behind the front bumper, right under the headlight. You can access it by removing the plastic cover in the wheel well.
• Check if power is going to the air suspension compressor. You can unplug the electrical connector that goes to the air suspension compressor, as shown in the picture below.

• Use a multimeter to test if there is 12-volt power at the connector. If you don’t have a multimeter, consider getting one, as they are handy for car troubleshooting; here is a list of highly rated digital multimeters. Press the Raise Vehicle button to engage the compressor, as it does not work constantly.

 

We must look at the relay and Fuse if you get a very low reading. If no power goes to the air suspension compressor, check the air suspension fuse and relay. Here is a picture that shows no power to the air suspension pump.

The next step would be to use a professional diagnostic scanner such as the YOUCANIC Full System Scanner to check the fault codes for the Air Suspension Control Unit. You will have to invest around $200 on the scanner, which will pay for itself quickly. If you plan on owning a Mercedes-Benz for a while, consider investing in one of the advanced OBD II scanners mentioned above. It will make troubleshooting your Mercedes-Benz much easier. You will be able to check any of the control units for fault codes and reset them.

Failed, defective air suspension compressor/pump.

If 12 volts or higher goes to the air suspension compressor, but the compressor does not engage, you have a defective air suspension compressor. Another symptom of a failed air compressor is when your Mercedes-Benz is completely lowered to the ground on all four wheels. Follow these instructions on how to change the air suspension compressor.

Follow these DIY instructions on how to replace the air compressor.

Failed Air Strut

 If one of the air struts fails, typically, the vehicle will fall only on the front or rear end, depending on where the faulty air strut is located. This is because if one of the failed air struts is on the front passenger side, the driver side will also sag. Only one strut on the front cannot keep the front of the car up. If you investigate closely, you may notice that as the car’s front or backdrops, it will drop more on one side than the other. The wheel where you see the vehicle lowered the most is typically the air strut that may be leaking. Top seals in the strut fail or wear, and they will develop air leaks over time.  

You can quickly check if you have an air leak at the mastic at the top of the strut. Spray some water and soap and carefully watch if bubbles form.

You can replace the air strut with a new one, but you may regret buying a Mercedes-Benz if you get a quote on this repair. Don’t worry; there are a couple of Do It Yourself solutions to this problem that will not break the bank.

1. You can use Epoxy Hack(Cheap and Dirty Repair, usually works)
2. Airmatic Strut Shock Repair Kit (Official repair, still much less expensive than strut replacement)

These solutions have been shown to work. Some auto repair shops may not try the epoxy solution, as they can’t guarantee their work and make little profit. If you don’t feel comfortable with the two solutions mentioned above, your next best bet would be to install a refurbished or new Arnott air strut. They are slightly more expensive than the two proposed solutions but still cheaper than replacing them with dealer parts. You can find Arnott air suspension compressors and struts on Amazon. You can check the latest prices by visiting the Arnott air suspension Online Products

Epoxy Solution

This is the least expensive solution. It is not guaranteed how long this will last. It can last for years or months. It may be worth trying, but research before trying this approach. You can complete this repair in just a few hours if you have the patience and about $20 to invest. This is what you will need.

Required Tools and Materials

• Epoxy (You can use J-B Weld Epox or PermaPoxy 4 Minute Multi-Metal)
• Drill steel wire brush.

Click here to download instructions on performing this repair provided by robledoch BenzWorld Member.

Let the epoxy cure completely. If you use the J-B Weld Epoxy, it takes up to 16-24 hours to cure fully. There are epoxy compounds that cure faster, make sure to read the direction on the back of the epoxy to allow it to cure before you pressurize the system again.

As you fill the air struts/spring again, ensure the bellow covers are extended down and not folded upwards. You can pull the covers downwards by hand. Once you do this, lower the car before activating the air suspension and pressuring the system.

Once you complete this repair, use tape to seal the brass fitting on top of the air strut. Otherwise, a small leak may develop and cause your car to drop when parked for a few days.

Airmatic Strut Shock Repair Kit

This is the same repair that is often performed by Mercedes-Benz dealerships. In this process, you must remove and replace the top seal. The root cause of strut failures. Here is an original listing of the Mercedes Benz Air Suspension Strut Shock repair kit Part Number 2203202538

Here you will find the WIS instructions on replacing the top seal.

Download: WIS Air Suspension Top Seal Replacement Procedure (by BenzWorld).pdf

To replace the air strut seal, you will need the replacement kit.

Watch this video on how to replace the top strut seal.

 

Note that the repair itself is not complicated. It would be best if you filled the air spring plunger correctly. There are a couple of ways to perform this. You could pull down on the air spring plunger as you activate the fill/raise process of the air suspension. This is described in detail in this document that you will find here: How Mercedes-Benz dealer fills the air suspension spring (PDF). If you accidentally damage the air spring below the covers, you can purchase new ones online without replacing the whole strut.

Inspect for air leaks.

Air leaks are challenging to troubleshoot, mainly if you use water and soap methods. You will spray the lines and the different components with soap and water and look out for air bubbles. While it can be done with soap and water, to make this challenging task more accessible, we recommend using a solution designed to help you find air leaks. Most of these products cost less than $10 and help you find air leaks faster and easier. One of our favorite leak detectors is the Hercules Mega Bubble Leak Detector, which sells for less than $10 on Amazon. With this leak detector, even if there is a small leak, it will show a bubble immediately, which you may miss with a soap and water mix.

Once you choose the solution of your choice, you need to spray the solution at the following locations.

• air suspension compressor fitting
• Air Lines
• Fittings at the valve block
• Spray along the air hoses
• Connection at the air tank / central air reservoir
• Joints, the brass valve on top of the air struts
• Level control valve block

As you apply the leak detector on these locations, check them in the next 5 to 15 minutes. Some leaks are soo small; they may take a few moments to form.

The valve block is less likely to be the problem, but they are also known to fail. Disconnect the lines to the compressor or the air reservoir to test the valve block. Apply leak detectors at those locations to make sure they are not leaking.

If any lines, pipes, or hoses are leaking, you must purchase airlines to repair the damaged section. You will often find the airlines on eBay much cheaper.

Level Control Valve Block

The valve block unit (Y36/6) is near the air suspension compressor. In the case of the W220 S-Class, it is located on the right side, between the passenger side headlight and the air suspension compressor. The valve block contains valves that open and close to direct the air pressure sent to each air sturt. The air is fed from the air suspension compressor or the air reservoir.

Level Sensors

You will also find the level sensor equipped with the air strut at the wheel. These sensors are used to gather information on the level at the axle. If the sensors don’t function properly, they can trigger an AirMatic malfunction in the instrument cluster.

The sensors detect the vehicle level at the axle and send a resistance reading to the air suspension control unit.

Input Sensors

Several sensors in the vehicle provide data and feedback for the air suspension control unit. Some of these components include:

• ESP control module
• Engine control module
• Transmission control module
• Instrument cluster
• Steering angle sensor
• Comfort and sport switch
• Level adjustment switch
• Vertical and horizontal accelerometers
• Front axle level sensors
• Airmatic pressure sensor

Air Filter

Most owners don’t even know an air suspension compressor filter exists. After all, it is well hidden. The air suspension compressor filter should be replaced as it is considered a maintenance item. If the filter gets clogged, it can dramatically impact the life and efficiency of the air suspension compressor. The filter part number A2203200069 costs only a few dollars when purchased online.

Check the price on Amazon.

Check the price on eBay.  

Alternative – Convert Air Suspension to Coil Spring

Some owners spend a lot of money on air suspension repairs. You may want to consider air suspension removal and convert the four wheels to coil springs. There are aftermarket suspension conversion kits for Mercedes-Benz that even include the fix for the control module so that you never get that air suspension warning message again.

Converting to coil springs will cost you between $1200 to $1500 for parts alone. Strutmasters are a well-known brand that makes aftermarket air suspension conversion kits. You will find their kits on Amazon. Here are some listings so you can know how much buying these kits will cost.

Conclusion

Hopefully, this article helped you find the problem with your suspension, and you could fix it without spending thousands of dollars. 8 out of 10 owners may likely have one of the problems described here. 

If all fails, there is another way to diagnose the air suspension. You can use a diagnostic scanner to retrieve and erase the fault codes. Most advanced OBD II scanners will read and clear the airbag, air suspension, transmission, and other system trouble codes. It will be even better if you have a YOUCANIC Full System Scanner with which you can conduct a series of tests to determine which air suspension component has failed.

If you tried the tips and tricks on this page and still can’t find the problem, your next step is obtaining a diagnostic scanner for further diagnosis and troubleshooting. Plug the scanner into the OBD II port, and it will tell you more about your problem than what we can in this article. 

What is the Best Scanner for my Mercedes-Benz?

If you’re experiencing problems with your Mercedes-Benz, the YOUCANIC full system diagnostic scanner can provide invaluable assistance in troubleshooting the issues. By connecting to your car’s onboard computer, the scanner can read fault codes and provide detailed information about any problems with your engine, transmission, brakes, and other systems. Additionally, the scanner can perform diagnostic tests on various systems, such as the ABS, airbag, and steering systems, to help identify the underlying cause of any issues.

In addition to providing diagnostic information, the YOUCANIC scanner can save you time and money on repairs by enabling you to perform simple fixes yourself. For example, if you notice the check engine light on, the scanner can assist you in identifying the problem and determining if it’s a simple issue you can address at home or if you need to take it to a mechanic. This can help you avoid unnecessary trips to the repair shop, saving you both time and money.

Overall, the YOUCANIC full system diagnostic scanner is a powerful tool to help you maintain and troubleshoot your Mercedes-Benz. It’s an excellent investment for both DIY mechanics and professional technicians, as it can assist in diagnosing and resolving even the most complex automotive problems quickly, saving you time and money on costly repairs.

Air Suspension AIRMatic and ABC Encyclopedia Resources

• Assembly Instructions Mercedes S-Class DC W220 Airmatic (not models with ABC)
• Airmatic Shock Installation Mercedes-Benz S-Class W220 by Bilstein
• Overview of AirMatic Documentation WIS
• Mercedes Benz W220 Front Air Spring Replacement (VIDEO)
• Mercedes Benz S-Class Front Air Shock Replacement with Arnott Aftermarket Replacement Parts
• Air Suspension Fix Documentation (Forum thread on BenzWord)
• Rear Air Strut Removal and Installation of Arnott Replacement Parts
• Mercedes Benz ABC System Troubleshooting Guide
• AirMatic In-Depth Review