In this brief article, we are going to discuss the different Mercedes AirMatic Air Suspension problems, what the causes are, and Troubleshooting Tips.
What are the most common issues in the Mercedes Airmatic Air Suspension?
The components of the AirMatic suspension that are most likely known to fail are:
- Front Air Strut Assembly
- Rear Air Bellows
- Valve Block
- Ride Height Sensors
What is Mercedes AirMatic Air Suspension?
The Mercedes-Benz Airmatic System is a product of decades of research in Air Suspension. There is no doubt that it is a huge Step-up over the less complicated coil-spring setup. The advantages that AirMatic has over the traditional coil-spring suspension are:
Auto leveling maintains the suspension at one Ride-height and compensates for additional passengers or cargo added to the car. There is a distinct advantage in maintaining the Center of Gravity, and therefore, the handling dynamics exactly the way engineers designed it.
Auto Height Adjustment
The Airmatic system will automatically lower the car in order to improve aerodynamic efficiency. It results in a more stable car at highway speeds, and also improves the fuel economy.
In situations like rough roads, speed bumps, or steep driveway entrances, the AirMatic allows you to raise the suspension Ride height so you can clear obstacles.
Selectable Driving Modes
In the Airmatic System, the driver can alter his car’s suspension Damping behaviour as per his preference by selecting one of three distinct driving modes: “Comfort”, “Sport 1”, and “Sport 2”. The driving modes vary from Soft feeling “Comfort” settings to Track-oriented and harder “Sport 2” settings.
Adaptive Damping System (ADS)
The ADS works in parallel to the AirMatic System and complements it in many ways. In ADS, instead of selecting a Driving mode, you can also allow the damping profile/driving modes to auto-adjust from “Comfort” to “Sport 1” when driving at speeds of over 100 mph. The adjustments are also based on Inputs from the horizontal acceleration sensors. The AirMatic and ADS features are probably the Best balance between Ride Comfort and Handling Safety.
Which Mercedes Models come with AirMatic as standard?
The Models that offer AirMatic suspension as standard are:
GLE Coupe (“AMG Sport Suspension” which is based on AirMatic)
Pro Tips to Troubleshoot Mercedes-Benz Airmatic Suspension
Rear Suspension Air Spring Failure
- The rear suspension Air Springs are the most common failure-Prone.
- If you observe that one side of the rear is lower than the other, this is a symptom of Air Spring failure.
- To verify that one side is lower, raise the vehicle to the highest setting and then lower it.
- From there, measure the ride height at each corner of the vehicle and record.
- Keep the air suspension Module disconnected overnight. Unplugging the suspension module will prevent the vehicle from Self-adjusting automatically while it sits overnight
- Now measure the ride height after Reconnecting the AirMatic Module.
- If the initial measurement and the measurement after the vehicle has sat overnight is lower on one side, it can be inferred that a faulty Air Spring is the root cause.
- While replacing the air spring with a Genuine or OE component, it is OK to replace just the single failed unit.
- While replacing the Air Spring with an aftermarket unit, both the failed side as well as the opposite side should be replaced simultaneously. If you do not have the MB recommended scan tool to carry out a level calibration after the air spring replacement, this becomes exceedingly important. The calibration exercise is carried out to account for the differences in air volume that occur with aftermarket products that omit the additional Air reservoir.
Weak Airmatic Compressor
- In case of a weak compressor, the vehicle suspension will either not rise or may rise slowly.
- In case you have the appropriate scan tool, you will find that the fault codes for “critical vehicle level” or “recovery time during filling” appear.
- A properly functioning compressor will output a minimum of 10 bar on the scan tool. Output can also be double-checked using a Normal analog Pressure gauge at the compressor output.
- A compressor that doesn’t run at all could be due to complete damage or lower than required voltage to the compressor.
- It is also possible that relays stick and burn out a compressor.
- If there is sufficient battery voltage supply at the suspension compressor terminals and it still doesn’t run, make sure to replace both the compressor and the compressor relay. If the battery voltage supply does not reach the compressor, replace the relay and fuse and re-test.
Failed Front Strut Assembly
- Failed front Air Struts normally will fill initially and then almost immediately start to drop when they fail to hold the required pressure.
- An audible hissing at the strut assembly while attempting to fill itself is a telltale sign of front Air Strut failure.
- If the air strut fails to rise with the compressor activated, then try to manually fill the strut with external pressurized air supply with the proper nozzle to confirm that this is not happening due to a compressor issue.
- In case it is not a case of a failed Air Strut, then the other possibility is a weak compressor or an air leak somewhere between the compressor and the valve block, or, between the valve block and the strut.
Level Sensor Failure
- If the vehicle is noticeably low but there is no ‘red’ error message on the instrument cluster reading “vehicle level too low”, then one of the level sensors (or its linkage) must be at fault.
- This is a common issue after driving over a large bump or a big-sized pothole, or if the rear level Sensor linkage gets bent.
Height Loss Overnight in Cold Climates
- A certain amount of suspension drop (upto 30 mm during the course of a day) should be normal in extremely cold climates.
- This happens as a result of thermal contraction. This is normal and well within the range of engineered parameters.
How long do AirMatic Air Suspension Components last?
|Component||Average Life||Watch out for|
|Front Air Strut Assembly||~100K Miles||Air bladders begin to failHissing Noise while RaisingDamper deterioration|
|Rear Air Bellows||~115K Miles||Leakage at the hose connection at the reservoir Air Bellow Rubber rupture from ageSolenoids are part of the Set of rear Air BellowsIf one rear side is lower than the other it is mostly a faulty Air Bellow|
|Dampers||~ 115K Miles||As Dampers age you will notice the degradation of the ride quality.You might also notice increased side-to-side body motion as well as increased pitching and diving motions|
|Valve Block||No fixed Mileage||Newer models like W211/ W219 are less failure prone compared to older version W210/164Remove an airline from the valve block and observe internally using a Flashlight if there is aluminum pitting or oxidationIf so, then replace|
|Ride Height Sensors||No fixed Mileage||Ride height sensors fail sporadically Sensor brackets either get bent or damagedFailure results in very high or very low ride Height at a corner that does not settle|
In this brief article we have discussed the different Mercedes Active Body Control Suspension problems, what the causes are, and Troubleshooting Tips.