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AIRMATIC Malfunction Mercedes GL450 (X164) Suspension Issue Explained
GL450 ride height adjustment is a key function of the Airmatic suspension system, allowing the vehicle to adapt to different driving conditions by adjusting its height. When an Airmatic malfunction occurs, the system may fail to raise or lower the vehicle properly, triggering warning messages and affecting overall ride comfort.
To address this, it’s essential to retrieve data from the Airmatic control unit to understand how the system is behaving.
mercedes gl450 air suspension malfunction issues often require a detailed analysis of sensor readings, valve block activity, and compressor performance.
By examining this data using diagnostic tools like Mercedes XENTRY, technicians can pinpoint the source of the problem whether it’s a faulty level sensor, a leaking air spring, or a communication error in the control unit.
Accurate diagnosis ensures the right repair and restores the suspension’s smooth, adaptive performance.
Air Suspension Mercedes GL450
The Mercedes Benz GL 450 Class is equipped with an AIRMATIC Air suspension with ADS and expanded off-road functions. The AIRMATIC can adjust various levels and simultaneously serves as a level corrector to compensate for loading influences.
The Adaptive Damping System (ADS) is an electronic control system, with fully automatic operation that adapts the damping force on each wheel to momentary needs.
It offers the following advantages:
• The vehicle level remains constant within the permissible loading, maintaining the optimal gap between the wheel and the fender.
• To increase ground clearance, the vehicle level can be raised or lowered as needed using the control unit wheel for off-road functions (+80 mm/-45 mm).
• To reduce air resistance, the vehicle is automatically lowered at high speeds. This improves dynamic stability and reduces fuel consumption.
The off-road package has 5 different levels between +80 mm and -45 mm. The normal vehicle level is -30 mm.
Overview of the different vehicle levels:
• High-speed +45 mm
• Road +30 mm
• Off-road 1 0 mm
• Off-road 2 +50 mm
• Off-road 3 +80 mm
The Air suspension system, fully supporting, offers a soft basic suspension with a low natural frequency. Ride comfort and dynamic stability are further improved by the ADS system.
Compared to a passive system with constant damping adjustment, the vehicle is optimally stabilized in all driving situations based on the chassis setting. Dynamic stability is improved, and body stabilization is more noticeable.
Two control valves integrated into the ADS modules, arranged parallel to the monotube gas dampers, allow for four different damping curves to be generated. Additionally, a control switch allows for selection between “Auto,” “Comfort,” and “Sport” damping levels.
The main components of the Air suspension with ADS include:
• Air suspension struts on the front axle with integrated ADS dampers, pneumatic spring, and separate ADS damper on the rear axle
• Electrically controlled compressor
• Air suspension valves and central pressure sensor
• Central accumulator
• AIRMATIC control unit
• Sensors for level correction and damping regulation
• Control element with wheel and 3 LEDs (level corrector)
• Control element with switch and 2 LEDs (ADS)
• Display in the instrument cluster
Common AIRMATIC Faults & Symptoms
| Cause | Symptom | Diagnostic & Repair Actions |
|---|---|---|
| Weak/faulty air compressor | Vehicle unable to raise height; sagging | Test compressor voltage and pressure; replace if underperforming |
| Faulty relay or blown fuse | No compressor activity; error warning | Inspect relay, fuse; replace as needed |
| Leaky air struts or valve block | One side lower; vehicle droops | Pressure leak test, inspect/replace strut or valve block seal |
| Control unit or sensor fault | Malfunction light-auto reset on restart | Read AIRMATIC codes via XENTRY; replace module or sensor if faulty |
Diagnostic & Repair Flow
- – Turn on ignition to power compressor listen for hum and watch pressure readout on AIRMATIC module.
- – Perform fault code scan of AIRMATIC module and ride height sensors via XENTRY.
- – Inspect air compressor relay, fuses, and power connections.
- – Test compressor output to confirm full pressure; replace weak units.
- – Examine air struts and valve block for leaks use soapy water for bubble test.
- – Replace leaking components and recalibrate ride height via diagnostics.
- – Clear fault codes; recommission system and ensure normal function.
CASE STUDY: Airmatic Malfunction Mercedes gl450
A client has reported experiencing an Airmatic malfunction warning on the dashboard of their Mercedes GL450. Although the warning disappears upon restarting the car, it reappears after some time.
After the intervention of a qualified technician, faults related to the vehicle’s level are found recorded in the Airmatic module unit.
He discovered that after starting the vehicle, the air suspension compressor was not functioning as expected. Upon inspecting the power supply to the air suspension compressor, it became evident that the issue lay within the compressor itself.
This diagnosis suggests that the compressor unit may be faulty or experiencing technical issues that are impeding its operation.
Further examination and potential repair or replacement of the compressor unit may be necessary to restore proper functionality to the air suspension system of the vehicle.
It underscores the importance of thorough diagnostics by qualified technicians to pinpoint and address the root cause of malfunctions effectively, ensuring the vehicle’s optimal performance and safety on the road.
Yes, typically when replacing the air suspension compressor, it is advisable to also replace the compressor’s relay in the fuse box. The relay plays a crucial role in controlling the power supply to the compressor, ensuring its proper functioning.
Over time, relays can wear out or develop faults, which can lead to issues with the compressor’s operation. By replacing both the compressor and the relay simultaneously, you can ensure optimal performance and reliability of the air suspension system.
It’s a preventive measure that can help avoid potential future malfunctions and ensure the longevity of the newly installed compressor. Always follow manufacturer recommendations and consult with a qualified technician to ensure proper installation and compatibility with your vehicle’s system.
Mercedes gl450 air suspension compressor Location
The Air suspension compressor is located behind the fender liner in the right front fender in Mercedes gl450, as seen in the image below.
How to replace the Gl450 air suspension compressor ?
Mercedes GL450 Air suspension compressor replacement
To replace the Air suspension Compressor on a Mercedes GL450, you can follow these steps:
1: Turn off the ignition and place the key fob out of range (at least 2 m) from the transmitter.
2: Remove the front part of the fender lining in the right front fender.
3: Loosen the clamps and remove the air intake hose.
4: Disconnect the electrical connectors.
5: Loosen the pressure line from the AIRMATIC compressor.
6: Unscrew the nuts and remove the AIRMATIC compressor.
7: Replace the AIRmatic relay.
GL450 Airmatic relay location
The Airmatic relay is located in the fuse box in the right side of the engine compartment, as seen in the image below.
GL450 airmatic relay is G, seen in the image below
Mercedes gl450 air suspension reset
How do i reset my Mercedes GL450 AirMATIC ?
To reset the Airmatic suspension on a Mercedes GL450, you can follow these steps:
1: Start by parking the vehicle on a flat surface and turning off the engine.
2: Open the driver’s side door and locate the button for raising the vehicle height. This button is typically located near the center console or on the door panel.
3: Press and hold the button for raising the vehicle height for about 5-10 seconds. This action should initiate the reset process for the Airmatic suspension system.
4: After holding the button, release it and wait for a few moments. You may hear some noises or see some lights flashing as the system resets.
5: Once the reset process is complete, turn the ignition to the “ON” position without starting the engine. Check the instrument cluster for any error messages related to the Airmatic suspension system.
6: If there are no error messages and the suspension appears to be functioning normally, you have successfully reset the Airmatic suspension system.
DIY vs Professional Tasks
| Task | DIY‑Friendly | Professional Recommended |
|---|---|---|
| Test ride height and listen for compressor | Easy | — |
| Check and replace fuses or relay | Moderate | — |
| Scan for fault codes (XENTRY/OBD) | Intermediate | Ton tool or dealer |
| Inspect and replace strut or valve block | Technical | Specialist service |
| Replace air compressor or control module | Not DIY | Mercedes technician only |
Frequently Asked Questions
Is it safe to drive with an AIRMATIC malfunction?
It’s okay for short, cautious trips however, the ride will feel lower and rougher, and handling may be compromised.
Why does warning reappear after restart?
Often due to intermittent compressor failures or air system leaks that briefly self-reset.
How do I know if the compressor is bad?
Scans show pressure faults; aftermarket testers can measure output if it fails to maintain pressure, it needs replacement.
Can I drive without replacing it right away?
Short-term yes, but unresolved issues can damage other suspension components or drop ride height completely.
