In this brief article we are going to discuss the different Mercedes W222 S Class air Suspension problems, what the causes are, and Troubleshooting Tips.
What are the most common suspension issues in a Mercedes W222 S Class?
The most common Mercedes W222 S Class suspension issues are:
- Suspension Sagging
- Vehicle would be sitting low and unable to raise
- Squeaking Noises
- Suspension Error message
- Rear suspension Riding Lifted
W222 S Class Suspension
The Mercedes-Benz W222 was a sedan model range otherwise also known as the Mercedes-Benz S-Class, succeeding the earlier S-Class W221 generation. The W222 generation of S-Class lasted from 2013 to 2020.
The models under the W 222 were :
S 280, S 320, S 350, S 430, S 500, S 600, S 55 AMG, S 65 AMG, S 320 CDI, S 400 CDI
The basic Suspension set-up would be the same for subsequent generations as well. The W222 Air suspension, also called AIRmatic suspension had the basic set-up of:
- Front Independent double wishbone suspension with AIRmatic Strut and an anti-roll bar. The upper Control Arm is a single-wishbone for all vehicles.
The Lower control arm is a combination of 2 ‘Thrust Arms’ with 2 separate ball-joint connections to the knuckle.
- Rear 5 – link arrangement with an AIRmatic Strut and an anti-roll bar
The W222’s advanced suspension was the “Magic Body Control”, and was available as an option in the V8 engine models. “Magic Body Control”, which was a system that complements the already existing “Active Body Control” System. The Magic Body Control featured the new ROAD SURFACE SCAN function.
The ROAD SURFACE SCAN function was provided by a stereo camera located within the windscreen, which would scan the road terrain ahead up to 15 metres of the vehicle and feed precise images of the road contours to the suspension control system. The Magic Body Control system, in turn, would constantly calculate the best control strategy for overcoming unevenness such as prolonged bumps.
The suspension’s actual Control is performed by:
- varying the Damping Rates to either a tauter or softer setting in advance, and
- increasing or reducing the load on the wheel by means of an active hydraulic system
All of this is done in advance predictively, rather than reactively, as was the case in the pre-2013 version of Active Body Control.
W222 Suspension Sagging
- When parked for a while, one or more corners settles very low in height as compared to the remaining corners.
- On starting the vehicle, the corner would rise, but only temporarily before sagging again.
- The car would be at an uneven height even while driving
- The 2 major reasons behind suspension sag are:
- Leakage in the Air Strut
- Ride Height Sensor malfunction
Troubleshooting Corner Sagging: Airmatic Strut Leak
- The most probable cause would be damage to one or of the AirMatic Struts which led to a leakage and loss of air pressure.
- Therefore the particular strut was unable to maintain the required ride height
- One quick check you could do to verify that it is the Strut, is to press the ‘Axle Lift’ Button and watch how the suspension tries to raise itself.
- The Front generally goes up first in Axle-Lift. If there is a problem or leak in any one of the front Air Struts, then the suspension will either not be able to fully raise itself, or,
go up slightly and lower itself immediately, while the other corners are raised.
- In cases where the leakage is major, there will also be a “Hissing’ Noise while doing Axle-Lift due to the Air Leakage
Troubleshooting Corner Sagging: Failed Ride Height Sensor
- If the Ride Height sensor is broken, damaged or locked, it will cause the AirMatic system to get confused and not maintain ride height
Troubleshooting Corner Sagging: Calibration
- After the failed suspension components have been replaced, it is always necessary to do a suspension calibration
- Whenever the car is lifted and suspension components are replaced, the ride height sensors lose their reference of the normal ride height because components have moved with respect to each other
- In the Diagnostic tool there is an Automatic Calibration function available under the “Airmatic Suspension” menu called “Adaptation”
Vehicle sitting low and unable to raise
- Vehicle would be sitting low generally after being parked for a while.
- Even when the ignition is turned on, the suspension would not raise itself again
- In certain cases, there would be no compressor noise
- In some cases you might get this error message,
‘Stop, Car Too Low!’
The problem could be most likely due to an electrical fault. You should use an OBD II scanner and get it to display all the fault codes.
Troubleshooting Vehicle sitting Low: Leakages in the Air Lines
- If the suspension sits low, it mostly means that there is either ‘Low’ or ‘No’ pressure at the Air Struts
- There is a possibility of leakage at any of the connection points within the Air circuit.
- You can easily identify the points of leakage by spraying soap and water all over the entire air circuit lines and then observing for the appearance of bubbles.
- There is also the probability of leakages at the Air connection fittings in the valve block.
- For any connector fittings, in case of any leakages, be sure to replace the connector
Troubleshooting Vehicle sitting Low: AirMatic Compressor Failure
- If you find no compressor working noise, then this would most probably be the cause.
- The compressor would stop working in the following situations:
- Burn-out of the Compressor
- Blown fuses and Relays of the compressor
- leakages in the air lines leading to loss the of minimum pressure required to allow air suspension functioning
- In some cases, the compressor, though operational, will not be effective. This can be diagnosed by reading the Compressor Pressure sensor while the car is being lifted.
- The ideal pressure must be above 14 bar, so any reading below that is a sure sign that the compressor has failed
Troubleshooting Vehicle sitting Low: Blown fuses and Relays of the compressor
- It could happen due to either a voltage surge in the circuit or just simply due to age.
- Occasionally, a relay or fuse could fail due to loads over longer periods while engaging with the compressor.
- In a majority of cases, an overworked compressor is usually a sign that there is a leakage or blockage within the Air suspension system
Troubleshooting Vehicle sitting Low: Airmatic Solenoid Valve Block Malfunction
- The Valve Block has solenoid valves that control the pressure to each corner Air strut.
- A malfunctioning Valve block solenoid could block air to the air struts
- In normal driving going over uneven surfaces, the suspension makes ‘squeaking’ and ‘mild rattling’ noises
Troubleshooting Squeaking Noises
- The Mercedes Airmatic Strut has the Air Spring integrated with a damper/shock absorber inside
- Like with conventional shock absorbers, if the Airmatic Shock absorber or Damper fails and loses Damping oil, it would lead to internal wear if the piston and subsequent squeaking noises when the vehicle runs.
- The Airmatic shock absorber could fail due to:
- A part defect
- Incorrect assembly of the air strut top and bottom mounts
- Shock Absorber reaching its end-of-life, which generally between 80K to 100K miles of service
Rear suspension Riding Lifted
- The Rear suspension is at maximum Ride height at one or both then corners
- Rear suspension height does not come back to normal until the ignition is turned off.
Troubleshooting Rear suspension Riding Lifted
Two possible Causes for such a symptom:
- Rear Height Sensor is malfunctioning. If the Ride Height sensor is broken, damaged or locked, it will cause the AirMatic system to get confused and not maintain ride height
- Rear Height Sensor Calibration was not carried out. This needs to be done using a Mercedes Benz Diagnostic tool. The diagnostic tool has a calibration function that helps level the 4 corner suspensions.
In this brief article we have discussed the different Mercedes W222 S Class Air Suspension issues, what the causes are, and Troubleshooting Tips.