Attention! Do not perform any work with your's car suspension without the necessary qualifications!


  1. description of air suspension AIRmatic functioning
  2. System components
  3. Struts - overview, options
  4. Malfunctions in AIRmatic suspension

The Airmatic air suspension appeared in widespread use for Mercedes W220 as the standard. As an option it was set active hitopadesa ABC models S500 and S600 was only with the Active Body Control. All other models have from the factory Airmatic air suspension, which provides both static and dynamic support through four pneumococci. Each strut is a pneumatic cylinder and a damper assembled in one unit. In the strut Airmatic air is supplied from an air compressor located behind the front bumper of the car, near the front wheel. On the opposite side of the Central reservoir, which maintains the pressure through a pneumatic line and valve blocks. Valve unit connected to the computer that controls the system pressure, vehicle weight, Desired vehicle height, its position (angle) at the moment, and then sets the ground clearance accordingly to these data.

Features of air suspension Airmatic:

  1. The height of the vehicle is controlled both manually and according to the speed.
  2. Electronic control maintains the clearance line clearance in the front and rear axles in accordance with the driving conditions and vehicle load. When the vehicle is stationary the level is restored, if the difference of the axes exceeds +/- 10mm when opening the door or trunk lid. While driving, the level reconfigures itself, if there is a difference in clearance of the axes reaches more than +/- 20mm. The rest of the level movement regulated to +/- 10 mm every 15 minutes.
  3. The active damping system ADS (Active Damping System), which adjusts the suspension according to road conditions and driving style of the driver. Road conditions are determined by the vertical acceleration sensors on the body of the vehicle. The horizontal acceleration is determined by measuring the vehicle speed and rotation angle.

The advantages of the air suspension Airmatic:

  1. High level of driving safety and ride comfort
  2. Adapting the rigidity of the suspension to road conditions and driving style
  3. The center of gravity of the car decreases as ground clearance is automatically reduced at speeds above 70 km/h
  4. By reducing the clearance reduces wind resistance and vehicle fuel consumption
  5. Individual adaptation: an increase in the clearance of car on bad roads and when moving through obstacles; two possible levels of stiffness suspension for comfortable or sporty driving styles in the cars produced up to 08/99; three possible levels of stiffness of the suspension for comfort, sport and extreme styles of driving on the cars made after 09/99

System operation:

The Airmatic air suspension is not as advanced as ABC, but it responds to a change in road conditions and requires quite a lot of data in order to ensure proper functioning of the system and comfort for passengers.

Normal operation mode (engine is running): when the car is stationary, the level adjusted, if there is a difference between the height of the front/back axis by more than +/- 10 mm Measurement is performed when opening the door or trunk lid.

While driving, the level reconfigures itself, if there is a difference in clearance of the axes reaches more than +/- 20mm. The rest of the level movement regulated to +/- 10 mm every 15 minutes.

Depending on the situation, the pressure in the system to support both the compressor and the pressure reservoir. Compressed air from the tank is used only when necessary, so as not to pump air into the tank too often. This happens, for example, if the vehicle height falls below a critical level when loading the vehicle or if the driver has switched the system to "increased ground clearance". Pressure from the reservoir is also used when the vehicle is stationary to minimize noise. In a standard situation when the vehicle is moving, the air in the pneumatic stand is supplied directly from the compressor.

Reduced clearance of the vehicle is detected by the control module from the level sensors of the body when loading of the vehicle. When triggered, the solenoid valves air is supplied to the racks on the front or rear axle while Your Mercedes-Benz reaches a predetermined height. In addition, the pressure relief valve there is opened to reduce pressure in the rack when unloading the car (if not triggered locking system).

The “Wake-up” function (All occurs within 1 minute):

Parked car "wakes up" before starting the engine. The control module AIRmatic with ADS receives signals from the door contact sensor, or the sensor on the trunk lid that indicates that the driver may soon start the engine and drive the vehicle. The current vehicle level is checked immediately and corrected if necessary. The ground clearance on the front axle is considered critical if the full eversion of the wheels can not be guaranteed. In this case, the multifunction display in the instrument cluster displays a message to warn the driver: "Stop car too low".

If the control module has "awakened" (e.g., opening a door), then there is a period of free time before the driver started the engine, which adjusts the ground clearance of Your Mercedes. This reduces the waiting time required for the correction level and ready for driving more efficiently. The pressure in the common rail is used to lift the car worth. The compressor is only used if pneumatic reservoir is empty, the following conditions are true: if the ground clearance is reduced by more than 30 mm, it rises to a normal level air from the collector (if the residual pressure > 11 bar). In the fall clearance vehicle < -65 mm and the residual manifold pressure of 12.4 bar, and then air from the collector.

If the vehicle level rises more than 10 mm during unloading, it goes down to normal levels by reducing the pressure in pneumatic struts.

When igniting happens all the same, but without the time limit. When the ignition is switched off, the system monitors the pressure in the reservoir to be enough to "wake up" – roughly the same thing happened in the old W126, which pumped the vacuum in the manifold Central locking – coming out of the car, you heard the pump buzzing, which helpfully took care of the vacuum to your next visit.



The operation of the air suspension Airmatic with ADS control module can be divided into main stages:

  1. Receiving data from sensors for subsequent processing
  2. Logical data processing, giving "orders" to the system
  3. safety circuit

Receiving data:

The following input signals are processed by the logic component and are used for calculations or to provide additional information:

  1. Calculation of the vertical body acceleration
  2. Receiving signals from the acceleration sensors of the body
  3. Calculating the speed of a car
  4. Reading the data about vehicle speed
  5. A comparison of the data with a status signal speed
  6. The calculation of the longitudinal and lateral acceleration of the body
  7. Receiving data from the wheel speed sensor
  8. Receiving a signal from angle sensor of the steering wheel
  9. Calculation of productivity of the compressor
  10. Control of temperature and ambient pressure
  11. The increased pressure in the tank
  12. The performance and the speed of the car
  13. Readings of the level sensors of the car
  14. The calculation of the signal for control valve
  15. Receiving a signal of the vehicle level front left, front right
  16. The signal is received on the rear axle
  17. Calculation of the required pressure in the main tank
  18. Receiving a signal of the vehicle level front left, front right
  19. The signal is received on the rear axle
  20. Receiving data from the pressure sensors
  21. Calculation of the level of car
  22. Receiving data from the level sensors
  23. Information signals (control)
  24. The data from the brake light switch
  25. The signal from Comfort and Sport switch
  26. The signal from controller clearance
  27. The signal from the contacts in the doors, the trunk, from a remote control

Logical data processing

Incoming signals are processed in the logic component and converted into output signals.

  1. The signals from the acceleration sensors of the body (B24/3B24/8B24/9)
  2. The vertical acceleration of the body is calculated using the signals from the acceleration sensors of the body.

Indicators the front wheel speed, left and right:

  1. Used indicators wheel speed data from control module ESP
  2. vehicle speed
  3. Longitudinal acceleration
  4. The condition of the vehicle. Reads the distinction between a moving and stationary vehicle.

The sensor signal of the rotation angle of the steering wheel (N49):

  1. Lateral acceleration of the vehicle is calculated using the signal from angle sensor steering signal and the speed of rotation of the wheels.

The signal from the level sensors (В22/8В22/9В22/3):

  1. Both the level sensor front axle give 2 signals. Sensors detect and transmit the distance between the center of the wheel and vehicle body with the left and right sides of the vehicle.
  2. The sensors of the rear axle are also giving out 2 signals. The sensor detects and reports the distance between the centre of the wheel and the body (with the difference that there is calculated the average of the left and right wheels).

Sensor brake (S9/1):

  1. When the driver presses the brake pedal, the signal of the logical component and the stiffness of all the racks is switched to "hard" which reduces to "peck" the nose of the car under braking.

"Comfort" and "sport" switch (N72/1s3):

  1. switching the air suspension mode "Comfort" and "sport" informs the system about the choice made by the driver between a comfort and sport 2 settings of stiffness. The "Comfort" mode provides damping within the comfortable range as far as driving style and road conditions. Mode "Sport 1" makes the suspension travel a little more harsh. "Sport 2" immediately sets the damping force to maximum. Set the driver settings are stored until changed by the driver (even with ignition off).

Signal levelling switch (N72/1s2):

  1. The control module uses the signals from the switch level adjustment to determine the driver's preferences concerning the level of the car:
  2. Normal level
  3. increased ground clearance


  1. The control module uses measurements of vertical, longitudinal and lateral acceleration and body speed to determine the optimum level of stiffness pneumococci. 4 different levels of stiffness can be set for each wheel, controlled by valves positioned on the racks. For example, the stiffness is automatically set on sport 1 at a rate of speed >160 km/h.
  2. Checking and adjusting the clearance
  3. The control module uses the settings from the switch of the height of the vehicle selected by the driver and vehicle speed to appropriate levels of control using control valves and sets the correct level of the vehicle in accordance with vehicle load.
  4. AIRmatic air suspension is fitted with pressure tank to make the time of level changes as short as possible (for example, to align the car after loading). Compressed air from the tank is used only when necessary, so as not to pump air into the tank too often. This happens, for example, if the vehicle height falls below a critical level when loading the vehicle or if the driver has switched the system to "increased ground clearance". Pressure from the reservoir is also used when the vehicle is stationary to minimize noise. In a standard situation when the vehicle is moving, the air in the pneumatic stand is supplied directly from the compressor.

Compressor control

The compressor is controlled through the relay. Since the compressor is not designed for continuous operation, duration, and cooling phase are monitored to avoid overload of the compressor.

Function Wake-up

Parked the car "wakes up" before starting the engine. The control module AIRmatic with ADS receives signals from the door contact sensor, or the sensor on the trunk lid that indicates that the driver may soon start the engine and drive the vehicle. The current vehicle level is checked immediately and corrected if necessary. The ground clearance on the front axle is considered critical if the full eversion of the wheels can not be guaranteed. In this case, the multifunction display in the instrument cluster displays a message to warn the driver: "Stop car too low".

If the control module has "awakened" (e.g., opening a door), then there is a period of free time before the driver started the engine, which adjusts the ground clearance of Your Mercedes. This reduces the waiting time required for the correction level and ready for driving more efficiently. The pressure in the common rail is used to lift the car worth.

The compressor is only used if pnevmoservis empty. Lock function If the control module detects that all the wheels of the car are discharged when the latter is stationary, the valves are closed, to keep the vehicle at its current level. This is important, for example, when changing wheels or when carrying out repair work (on a lift).

Safety circuit

In the air suspension Airmatic with ADS control module monitors all important system components after switching on and in operation. The safety circuit monitors the operation of the sensor, a faulty control module and electrical components of the system. If a malfunction is detected, the system stops and a message appears on the multifunction display of the instrument panel, to alert the driver. The valve body is no longer controlled and pneumococci switch to "hard" (hard level for driving safety). In addition, the DTC is logged in the control module. The clearance control is partially switched off depending on the type of fault - the system always strives to maintain the selected vehicle level. In addition, the safety circuit continuously monitors battery voltage. If the voltage falls below 10.5 V or exceeds 17.5 V, the system is disabled until then, until the voltage returns to the specified range.

The components of the pressure

Компоненты подачи давления пневмоподвески AIRmatic

42 - Airmatic central collector

А9/1 - Pneumatic compressor AIRmatic

Y36/6 – valve control clearance

In normal mode air suspension AIRmatic works with a pressure of 6 to 10 bar depending on load. Electric compressor is used to supply pressure. In addition to the Airmatic air suspension system includes a reservoir (42), which stores compressed air under a pressure between 13 and 16 bar. The pressure in the system is supported from the compressor when the vehicle is moving or from the tank when the vehicle is stationary, or simple compressor.

Management of the car level

n AIRmatic air suspension ground clearance front and rear axles supported by pneumatic suspension system. AIRmatic supports the body at a constant level when the engine is running regardless of the load. To do this, air from the air compressor is supplied to pneumococcal through the valve unit to adjust the level of the car. The ground clearance on the front axle is fixed and rear (with the difference that the front axle takes into account the indicators and the right and left, and on the back is just average) two level sensors, data is sent to the control module AIRmatic. The height of each of pneumococci controlled valve and the safety valve on the compressor.

Components of air suspension AIRmatic

The location of the electrical/electronic components:

Схема расположения электрических/электронных компонентов AIRmatic

А9/1 – Compressor of air suspension AIRmatic N49 - the angle sensor of the steering wheel
A1p13 - Multi-function display N51 - the control module AIRmatic with ADS
В7 - AIRmatic Pressure sensor N72/1s2 – switcher of the clearance
В22/3 – level sensor rear axle N72/1s3 – the mode selector comfort/sport
В22/8 – height sensor left front wheel S9/1 – limit switch-brake light
В22/9 - height sensor right front wheel Х11/4 – computer output
B24/3 - left front acceleration sensor body Y36/6 – valve block
B24/4 - right front acceleration sensor body Y51 – valve, front left strut
B24/6 - right rear body acceleration sensor Y52 - valve, front right strut
К40/7 - right front fuse and relay module Y53 - valve, rear left strut
к0 – relay of air suspension compressor AIRmatic Y54 - valve, rear right strut

Air suspension AIRmatic, location of pneumatic components:

расположение пневматических компонентов AIRMatic

40 - front strut Y36/6 – valve block of air suspension AIRmatic
41 – rear strut Y51 – valve, front left strut
42 – main collector of air suspension AIRmatic Y52 - valve, front right strut
А9/1 – compressor AIRmatic Y53 - valve, rear left strut
  Y54 - valve, rear right strut

AIRmatic Air suspension compressor (А9/1)

Компрессор пневматической подвески AIRmatic
  1. М1 – motor-compressor
  2. а – air filter
  3. b – overpressure valve
  4. с - moisture separator
  5. g - the high pressure line
  6. h - mounting plate
  7. А9/1 - compressor AIRmatic
  8. В7 - AIRmatic pressure sensor
  9. М1 - air compressor engine
  10. Y36/6 – Valve block of the air suspension

Electric compressor creates the pressure required for lifting the car. Safety valve integrated in the compressor block is used for reducing the clearance of the vehicle.

Компрессор пневматической подвески AIRmaticThe main part of the compressor unit – the compressor and motor. It also has dehumidifier, filter, safety valves and valve blocks. The valve unit is fixed to the same mounting plate just above the compressor and it is powered by the pneumatic line, high pressure. I see no reason to go into meticulous study of the direction and sequence of flow of compressed air, the principle is clear.

Dehumidifier, as you know, removes moisture from this. Safety valve is installed in the compressor unit (Y1) is required to exhaust when lowering the car. The discharged air flows through the air cleaner back into the atmosphere. It also cleans the filter. The air drier is maintenance-free. The condensate is given back to the atmosphere during pressure relief.

Air filter

Interesting, but quite difficult to obtain information on the operation and planned maintenance of the air filter. In General, it is recommended to change the filter from time to time, to prevent damage to compressor air suspension AIRmatic. And that's how it is – who knows. I would suggest the same as the cabin filter (Yes, You have it). The filter can become clogged with debris and deposited salt in the winter after our caring dorozhnikov, which may block the filter. For W220 his room A2203200069. It costs 10 Euros in the original, and to replace it will be in 15-20 minutes.


Replacement of the compressor on the example of the W220

  1. high pressure mainline
  2. air intake with air filter
  3. the connector of the motor with the compressor
  4. А9/1 – air suspension compressor
  5. A9/1y1 – Relief valve overpressure

The procedure for replacing the compressor:

  1. Disconnect the battery.
  2. Remove the fender liner (right front section).
  3. Disconnect the high pressure pipes (1) and the compressor (А9/1)
  4. Disconnect the connector valve excess pressure (A9/1y1).
  5. Disconnect the motor connector from the compressor (3).
  6. Pull the hose of the air intake with air filter (2) from side member.
  7. Remove the nuts fixing the compressor (А9/1).
  8. Disconnect the compressor relay (K40/7kO) only when installing a new compressor. Other works do not disconnect the relay to prevent damage!
  9. Install in reverse order.

Overview of components air suspension AIRmatic:

Valve block of the air suspension AIRmatic (Y36/6)

Блок клапановLocated on a compressor valve of the air suspension (part number A2203200258) is located in the right front fender. The valve block controls the ground clearance of the car, measuring how much air you need each of the stands. It has an electromagnetic valve for each wheel (y1, y2y3, and y4) for lifting or lowering the vehicle. AIRmatic air suspension with Central manifold (Y5) is connected with the valve block. The pressure sensor (B7) is located on the end of the block.

Polyamide pipes 6 lead from the valve block to the following:

1 - left front pneumatic strut
2 - right front pneumatic strut
3 - left rear pneumatic strut
4 - right rear pneumatic strut
5 - Central collector
Р - air compressor

For security reasons, only one valve can operate at the same time. If the bridge sank too low, pressure is supplied between the left and right valves alternately.

Car lift

Valves Y1Y2Y3 and Y4, respectively front left, front right, rear left and rear right are opened as necessary and the compressed air from the Central manifold or air compressor motor through a valve block (Y36/6) is sent to pneumococcal. As soon as the required level of the vehicle is achieved on the front wheel, the valve (y1 or y2) is closed, the other valve remains open as long as the level of the car also adjusts to the other wheel. On the rear axle both valves (Y3 and Y4) are closed when the vehicle reaches a predetermined level, intermediate between the right and left (remember, earlier we already stated that the height is read from each of the front sensors and the rear is taken from the average value).

Lowering the car

Open the valve all pneumatic struts (у1у2у3 и у4) and valve unit (Y36/6). With them open the pressure relief valve (Y1) to the Airmatic air suspension compressor (A9/1) and the compressed air escapes through this valve. Valves in pneumatic struts remain open until then, until the car reaches the required clearance.

Check for leaks

проверка пневмоподвескиOn the right side of the vehicle remove the wheel arch liner to get open access to the compressor and the valve unit.

Using a spray to check for leaks (or at least something like soap), spread it on a connection line 1, 2, 3, 4, 5, P on the valve block and wait for 10-15 minutes after spraying. This will help to detect minor leaks. Heavy leaks are immediately obvious.

Sometimes the valve fails when the valves are no longer holding pressure or not can be closed because of a hangnail. Theoretically, some some services can try to fix it, but how long the repair "hold" is like a lottery.

Pressure sensor of the air suspension AIRmatic (В7)

Located right in front of the valve block. Measures the pressure in the system and is used by the control module for checking the incoming data.


Датчик давления AIRmatica - Electronic module (hybrid)
b – the incoming pressure
c - line
d - metal case
e – glass core
f – glass seal
g - nominal pressure
h - pressure sensor
i - silicone oil
k - metal protective diaphragm

The sensing element compares the input pressure (b), which should be measured with a reference pressure (g) on the gauge. Pressure (b) is transmitted to the pressure sensor (h) with a metal protective diaphragm (k) and silicone oil (i). The electronics module (a) receives pressure data as analog voltage on the ECU is inside the metal casing (d).

Strut height sensor (В22/3, В22/8, В22/9)

  1. В22/3 – height sensor rear axle
  2. В22/8 - left front height sensor stand
  3. В22/9 - right front height sensor stand

These sensors determine the height of the vehicle front axle and the rear and pass the obtained value to the control module AIRmatic with ADS.

The design of the sensor 2 Hall sensor in one housing.

Determines the level of the vehicle with thrust provided from the upper transverse control arm left and right front axle. The sensor on the rear axle tracks the movement of torsion determines the average level of the vehicle. A sensor fault is detected by the control module by comparing the signals from each of the sensors.

The Central manifold pneumatic suspension AIRmatic (42)

Essentially a metal cylinder that stores compressed air to use it without straining the compressor once again. It is located on the left side, behind the bumper. (see photo)

Switch comfort / sport (N72/1s3)

This switch controls the adaptive damping system (ADS).

Switch indicators located at the top of the center console.

System the ADS automatically selects the optimum damping for the prevailing driving situation. Sport or comfort mode telling her about Your preferences at the moment.

The suspension tuning is set according to:

  1. Your driving style
  2. Road-surface conditions
  3. Your choice of suspension style, "sport" or "comfort", which you select using the damping switch.

You can choose from the following styles of the suspension:

  1. "Comfort" - both indicator lights (1) turned off.
  2. "Sport 1" – one indicator is illuminated (1).
  3. "Sport 2" – both indicators (1) are on.

The selected suspension style is stored in memory even after you turn off the car.

Switch level control auto (N72/1s2)

This switch controls the ground clearance of the car.

The following levels of height adjustment of the vehicle can be selected when the vehicle is stationary:

  1. "Normal" - for driving on normal roads. Light indicator is (1) off.
  2. "Raised" for driving on rough roads or when using chains. Light indicator (1) is on.

Choose the "Raised" setting option only when required by current driving conditions. Otherwise fuel consumption may increase and driveability could also be adversely affected.

The ground clearance is increased or decreased in accordance with the selected level value and vehicle speed (these adjust the clearance so small that you may not notice any changes):

  1. With increasing speed, the ground clearance is reduced to approximately 20 mm.
  2. With decreasing speed the ground clearance rises again to the selected vehicle level.

Selected clearance of the car is stored in the memory, even if the engine was switched and restarted. However, the lifted vehicle will reduce the clearance to a normal level when exceeding a speed of 120 km/h or if you will go in speed between 80 km/h and 120 km/h more than 5 minutes.

Control module of air suspension AIRmatic with ADS (N51)

The job control module Airmatic: to perform all the control functions of the ADS and airmatic. The control unit is in the left fuse block.

Incoming data. Module control air suspension AIRmatic receives input signals via CAN bus the following components:

  1. The control module ESP
  2. The engine control module
  3. Module transmission control
  4. Dashboard
  5. The angle sensor of the steering wheel
  6. Comfort / Sport switch
  7. Switch clearance
  8. 3 sensors of the body acceleration
  9. Two height sensor front axle
  10. Height sensor rear axle
  11. Pressure sensor air suspension

Outgoing functions. In air suspension Аirmatic input signals are processed by the control module that based on these data, generates output signals for the following components:

  1. Valve block
  2. Central collector
  3. 4 valves of ADS
  4. Multi-function display
  5. Indicators on the switches/mode
  6. Air compressor

Air suspension strut (40, 41)

Strut air suspension AIRmatic takes over all functions of the suspension control clearance, levelling and stiffness stroke.

40 - spring strut front axle. 41 - strut rear axle.

Stand design of the suspension: Monotube gas shock absorber, integrated pneumatic cushion. ADS valve is attached to pneumatic struts.

  1. 41 – Gas strut rear axle
  2. 40 - front one
  3. а – wall depreciation core
  4. b - the cylindrical tube
  5. c – gasket piston rod
  6. d – rod guide piston
  7. e - piston rod
  8. f - piston
  9. g - rubber stop for shock absorber springs
  10. h – air membrane
  11. i – rubber stop for shock absorber
  12. k - residual pressure valve
  13. l - the air chamber
  14. m - dividing piston
  15. n – protective boot
  16. o – camera high pressure gas

Operation: the weight of the car is distributed between 4 pneumostome that support clearance thanks to the compressed air in the air chamber (l), which are bottom sealed with a rubber membrane (h). Under dynamic loads during movement of the membrane being paired with aerial cameras, rolled and rolled parallel to the axis of the core, thus providing the necessary stroke of the rack. This whole area is isolated from the outside world by a rubber dust cover (n) to protect from dirt.

Ground clearance of the car is raised/lowered by increasing/decreasing the air pressure in the air chamber (l), which leads to a lengthening/shortening of the strut (40). Top rack mounted pneumatic valve (k), which blocks the air in the front on command of the control unit or when decreasing the residual pressure in the rack below 4-5 bar.

Replacement struts (for example, W220)


Front struts (no 4matic):

  1. A2203205113 (replaced by A2203202438)
  2. A2203202438

Front strits (4matic):

  1. Left: A2203202138
  2. Right: A2203202238

Rear struts:

  1. A2203205013
  2. A2203207913 (for option code Z04)
  3. A2203207813 (for option code Z07) (replaced by A2203202338)
  4. A2203202338 (for option code Z07)


Since BILSTEIN is a manufacturer of struts for W220, you can buy the original struts from BILSTEIN directly much cheaper.

  1. Front left (4matic): 44-051518
  2. Front right (4matic): 44-051525
  3. Front struts (no 4matic): 44-042295
  4. Rear: 44-042301


Here is a controversial issue. Arnott sells new and restored stands. Previously, they were only in the US but is now in Europe, respectively, to us they become closer. But before You start googling where to buy a stand Arnott, consider the following:

  1. Arnott argued that the use of special seals made exclusively for them by Continental and they simply last forever (well, at least supposedly go longer than the original). And in fact, Arnott provides limited lifetime warranty for their products.
  2. Arnott rebuilt strut are cheaper new (and still his old can pass, decent earning, BUT.... Arnott just install the new airbag and the membrane piston seal, gas shock absorber (bottom) nobody touches. I mean, yeah, the Pneumatics works. Does she stand and how much it will stretch??
  3. In fact, you can buy a kit supposedly production of Arnott and repair struts yourself much cheaper.
  4. There are still "own" version of Arnott – but.. They stand do not support the ADS (Active Dumping System). You plug them in, but they spelled out the team.. to fool the computer. Thus, they simply give the control unit false information, if the ADS work, although it is absolutely not true. Also, You will no longer be available modes Sport 1 / Sport 2

The damping valve (Y51Y52Y53Y54)

His task was to adapt the damping to the driving style and road conditions. The damping force is adjustable in the damping valves (Y51, Y52, Y53, Y54). Each wheel has one damping valve which is mounted between the upper and lower supports single-tube pneumatic shock absorbers. Each valve (you can tell, block) contains the two electromagnetic valves (U1, U2), which allows the unit to switch to one of the 4 possible settings of shock absorbers in accordance with the specific command valve module receives from the control module newportville AIRmatic with ADS. Extremely short response time (milliseconds) means that the optimum setting of the damping force is available almost immediately if sudden changes in the stiffness of the vehicle will be required - for example, during an evasive maneuver from the obstacle.


  • Y51 - left front damping valve
  • У1 – solenoid valve 1
  • У2 - solenoid valve 2
  • p - a piston valve unit

The damping valves (Y51, Y52, Y53, Y54) consists of a body and two piston valves, which are located above the coils and together form an electromagnetic valve (y1, y2). within the system contains the oil to absorb pressure fluctuations and abrupt loads.


The illustration shows the front strut of the front axle.

  1. 40 – Pneumatic strut front axle
  2. Y51 - The damping valve
  3. y1 - solenoid valve 1
  4. у2 - solenoid valve 2
  5. a - by-pass valve, high pressure intake
  6. b - by-pass valve, low pressure release
  7. с - by-pass valve, a large pressure release
  8. d - by-pass valve, low pressure intake
  9. f - control piston
  10. m - the dividing piston
  11. о – high-pressure chamber
  12. r - bottom valve

ADS control module pneumatic suspension is used to obtain four different settings of the system:

Setup 1 For a comfortable ride with low suspension and low vibrations longitudinal and transverse accelerations. In this case, both the solenoid remains open, allowing the oil to freely flow, thus absorbing the pressure fluctuations in pneumatic struts.

Setup 2 the System moves to a more strict regime, If the car is for some reason omitted, the electromagnetic valve V2 opens, and the solenoid valve Y1 is closed.

Setup 3 Reverse action from settings 2

Setup 4 When you switch to sport mode, or registration system sharp and strong longitudinal and lateral accelerations, to improve the safety car both solenoid valves y1 and y2 are closed. All the oil in the system is passed only under heavy pressure. This setting can also be activated whenever a failure in the suspension and its further transition to emergency mode, as You will be notified with an appropriate message on the multifunction display.

Malfunctions in the air suspension AIRmatic.

Let's start with the display. Sit (or go) you're in a car, suddenly hear the melodious bell on the display (А1р13) illuminates the message "AIRMATIC VISIT WORKSHOP!" This message on a white background means that the system electrical fault.

In case of electrical failure in the suspension system AIRmatic with ADS you see on the display "AIRMATIC VISIT WORKSHOP!", so, the originator of this message is identified and stored in the memory. Even if You restart the engine (and the system) and the message will disappear and the pendant will work fine, I advise you to go to the station and Old consider the errors to eliminate them.

It is important to remember that if there is a fault suspension goes into emergency mode – valve closes, the suspension becomes most hard, to change level of hardness, and the clearance is no longer available both manually and automatically)

Hit No. 2 - "AIRMATIC STOP, CAR TOO LOW!" And even red. This warning appears if the clearance of the car was the front axle by more than 50 mm (60 mm USA), or on the rear axle more than 60 mm (70 mm USA) below the normal level. The message will disappear if the level rises up to 48 mm or 58 mm (58 mm or 68 mm in the US), respectively, below the normal level. But the reason it is better to expose at once, especially if it's not just prosazhivanie due to a very long downtime. How to get to servise – see below.

Repair pneumatic lines

Leaks can be caused by a rupture or crack in the air pipe. There is one small problem – the line goes through the room and hard to get to leak, though it can even be clearly audible thanks to the loud chipasia sound. But it is possible to put an alternative line from the front valve Assembly back to inspect the line.

MB sells such things for the repair:

Air hose (A2203271045) Price EUR 14, length 1.5 meter. Factory pneumatic lines are solid, without joints. And those five feet – only to fix. Alternatively, you can search not original, its diameter is 4mm. I Think you can find cheaper 14 Euros
The following useful lot – such a beautiful fitting (A0003270169). Price 45 Euro.
But for those who think that "Golden" fitting is unsuitable to the color of the car can look for a replacement among the materials is 3 Euro meet.

Well, at the end of the article, a couple of tips:

If while driving you suddenly saw a red inscription "AIRMATIC STOP, CAR TOO LOW!", immediately stop (do not turn the wheels much) and inspect the car. If the do level fell below acceptable, you need to go to the station and look for the problem.

Do not drive with this problem – this will entail:

  1. The compressor will work continuously and simply burned up.
  2. If the strut is low, the tire will RUB the inner fender.
  3. There is a risk of damage to other stands on the same axis.

There is a workaround for the front struts, which you can use to get to the nearest workshop without the participation of the tow truck:

Step 1: take wooden blocks and cable ties Step 3: Insert the wooden block and secure it with cable ties
Step 2: Jack up the car Step 4: lower the car

Ride is stiff, but slightly stiffer than the “Sport” mode – most importantly, to drive one HUNDRED, and even wings with the wing flaps will be.

When the message "AIRMATIC VISIT WORKSHOP!" in white on the instrument panel, which means that the failure is electrical in nature, without a DAS will not do – need error codes.

If you see an error in 1 of the valve, for example, the code C1324-001 - Fault in component Y53y1 (Left rear solenoid valve 1) in assembly Y53 (left rear axle damping valve unit), then it is most likely to blame for the solenoid, but if multiple errors at once – most likely a poor connection, or similar variants.

"AIRMATIC STOP, CAR TOO LOW!" - red on the dashboard. Possible causes:

Compressor is dead - to test this hypothesis, start the car and see if it works (you should hear the compressor in the area of the front right wing). If it doesn't work, check the fuse and relay. A faulty relay can result in non-stop operation of the compressor, and it simply burned up.

Leaking strut - in case of severe leak you will hear a hissing sound at weak – it is possible to visually identify. It is very likely that the wheel with the other hand (or the wheel on the other axle on the same side) will also be much lower, but usually in a slightly lesser degree. Please note that the same symptoms can also occur when a fault line or block valves, as she strut has a residual pressure valve that will block the air outlet of the rack just in case the pressure drops below 4-5 bar, which can not be distinguished visually from a completely empty rack.

The line is not tight. It is possible that the line to the posts is cracked or cracks. In the case of the a-pillars line going from the valve Assembly to the racks you can check out the spray (see above). However pneumopathy going through the interior of the car to the rear axle just to get close. The easiest solution is to put an alternative line to bypass the "native". It's still not working – OK, looking on; work – dismantle the interior and replace the line.

The valve block is leaking. It is possible that the valve block is not serviceable and some of the valves are not closed, then the pressure will be released back into the compressor and out of the system. We have already written about the check valve.

The Central tank has lost integrity. If the test shows that the reservoir can no longer hold the pressure before you change it check coming to him line for leaks.

The level sensor is faulty. There are two clearance sensor for each front wheel and one for the rear axle. If the level sensor is reporting the wrong altitude, the system will think that the car already has the necessary clearance and will not raise vehicle. The information provided by the sensors can be viewed using DAS. If the car rises, but then drops again, the sensor height is likely not the reason.


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