• Product News
• 04 Jul 2026

Air Suspension and ECAS System Parts: ECAS Solenoid Valve, Leveling Valve and Height Sensor

In heavy-duty commercial vehicles, ride comfort, load balance and ride-height control depend on the correct operation of the air suspension and ECAS (Electronically Controlled Air Suspension) system. With more than 255 products, VADEN ORIGINAL offers a wide range of suspension components for trucks, tractor units, buses and trailers, from ECAS solenoid valves to leveling valves, height sensors and brackets.

What Is Air Suspension and the ECAS System, and What Does It Do?

In heavy commercial vehicles, air bellows and pneumatic control units have largely replaced classic leaf-spring or coil-spring suspensions. Air suspension carries the vehicle's load and dampens road shocks through bellows that are inflated and deflated with compressed air. ECAS (Electronically Controlled Air Suspension) is the electronic layer that manages this pneumatic system: it evaluates data from the height sensors, triggers the solenoid valves to regulate the air pressure sent to the bellows, and thereby automatically keeps the vehicle's ride height constant regardless of load condition.

Thanks to this system, chassis height, axle load distribution and ride comfort remain at an optimal level whether the vehicle is empty or fully loaded. ECAS also manages functions such as ramp access, easier loading/unloading (kneeling) and axle lift. Correct operation of the system is critical for both driver comfort and the safety of the load and the vehicle.

VADEN ORIGINAL Suspension and ECAS Product Groups

VADEN ORIGINAL's suspension and ECAS portfolio of more than 255 products covers all the critical components of the system:

• ECAS Solenoid Valve (171 products): The largest group in the portfolio. Based on the signal from the electronic control unit, it directs the compressed air sent to the air bellows, enabling ride height to be adjusted in real time.
• Leveling Valve: A complementary ECAS component that senses the vehicle's ride height mechanically/pneumatically and regulates the air flow to the air bellows accordingly.
• ECAS Height Sensor: A sensor that measures the distance between the chassis and the axle and feeds height data to the electronic control unit; effectively the system's "eyes."
• Bracket: Mounting components that securely attach the height sensor and valve assemblies to the chassis or axle.
• Check Valve: A valve that ensures air flows in one direction only within the air system, preventing pressure loss and backflow.

Brand and OE Compatibility

VADEN ORIGINAL suspension and ECAS parts are developed to be compatible with the Wabco and Knorr-Bremse systems widely used in heavy commercial vehicle fleets. This allows them to be installed as seamless replacements for OE parts on leading European truck, tractor unit and bus brands, including Mercedes-Benz, MAN, Scania, Volvo, DAF and Iveco. For fleet operators and authorized workshops, multi-brand support from a single supplier simplifies both stock management and maintenance processes.

Why Choose VADEN ORIGINAL?

With a manufacturing infrastructure certified to IATF 16949:2016 and ISO 9001:2015 quality management standards, VADEN ORIGINAL produces the precision-demanding components of the ECAS system to original equipment tolerances. Solenoid valve sealing, height sensor measurement accuracy and valve body pressure resistance are rigorously tested in every production batch. These standards ensure that VADEN ORIGINAL parts deliver long-lasting, reliable performance in both new vehicles and heavily used fleet vehicles.

Frequently Asked Questions (FAQ)

What symptoms appear on a vehicle when the ECAS solenoid valve fails?

Symptoms may include ride-height imbalance, the vehicle leaning to one side, increased jolting while driving, a suspension warning light on the dashboard, and in some cases the vehicle failing to rise or lower at all. A solenoid valve fault usually also appears as an error code in the ECAS control unit.

How often should the ECAS height sensor be checked?

The height sensor should be visually inspected during periodic maintenance, particularly during under-chassis cleaning and axle servicing, to confirm that the linkage arms show no signs of loosening or wear. For vehicles operating under heavy loads, a detailed inspection at least once or twice a year is recommended.

What is the difference between a leveling valve and an ECAS solenoid valve?

A leveling valve is a component, more common in conventional air suspension systems, that senses vehicle ride height through a mechanical linkage arm and directly regulates air flow. An ECAS solenoid valve, by contrast, operates on a signal from the electronic control unit, providing more precise, automatic height adjustment.

Which vehicles can use VADEN ORIGINAL ECAS parts?

They can be used on Mercedes-Benz, MAN, Scania, Volvo, DAF and Iveco trucks, tractor units, buses and their trailers equipped with a Wabco- or Knorr-Bremse-based ECAS system. For correct application, it is recommended to confirm the vehicle's chassis number and the existing part reference.

Why is the check valve important in an air suspension system?

The check valve prevents the pressure delivered to the air bellows from bleeding back, allowing the system to operate stably without pressure loss. A faulty check valve can cause the air bellows to deflate while the vehicle is parked and lead to delayed rising on the next start-up.

Conclusion

In heavy commercial vehicles, ride comfort, load safety and correct ride-height management depend on the healthy operation of every component of the ECAS system. By reviewing VADEN ORIGINAL's extensive suspension product range — solenoid valves, leveling valves, height sensors, brackets and check valves — you can select the right OE-compatible part for your vehicle. To view all suspension and ECAS products, visit the VADEN ORIGINAL Suspension Category page.