Mercedes Suspension Ride Height Level Sensor
Mercedes-Benz vehicles equipped with airmatic suspension have three to four Suspension Height Level Sensors. The airmatic suspension uses input from these sensors to automatically self-level the vehicle height based on the vehicle load.
Mercedes-level sensors determine the position of the airmatic strut, which determines the vehicle’s load. Level sensors are also known as suspension ride height sensors. A level sensor should not be confused with the axle damping valve unit.
How to Replace Mercedes-Benz Ride Level Sensor?
In the following video, you will learn how to remove and replace the level sensor on Mercedes-Benz with Airmatic suspension. The work was performed on a W221 S-Class, but the procedure is the same for other models, including Mercedes-Benz E-Class, GL-CLass, ML-Glass, CLS-CLass, R-Class, and other models with airmatic.What you will need
- Mercedes Suspension Level Sensor
- Torx Socket Set
Symptoms
If one of the suspension height level sensors fails, you will notice one or more of the following symptoms.
- Airmatic Malfunction Visit Workshop message on the instrument cluster
- Stop Car To Low message.
- The vehicle drops to the ground at one of the front corners.
- The strut is locked out at max inflation and very high
- The back of the car (both sides) drops to the ground if the rear axle sensor fails. The rear of the car will not raise even with new struts.
- Airmatic – Visit Workshop Displayed in Instrument cluster and Fault Code 5151 – [B22/3 (Rear Axle Level Sensor): Signal Implausible]
Troubleshooting Mercedes Level Sensor
When a Mercedes is taken in for another service, such as a control arm or air strut replacement, the mechanic working on the car accidentally bends the B22/9 or B22/8 sensor mounting plate linkage.
The airmatic control module no longer reads the correct vehicle heights. We recommend you check the level sensor link, wiring, and mounting place. From our experience, it is more common for the link to bend or fail than the level sensor. The link itself can often break, causing the level sensor to malfunction.
If you are experiencing problems with the airmatic, always start by checking the ride height level sensor links. Remove the front two wheels and inspect the suspension level sensor mounted next to the upper control arm.
You have level sensors at each front strut. Depending on the chassis, you will have a level sensor above the rear axle or one for each rear strut.
If you notice that the linkage is bent, you can bend the sensor back to the correct position. The problem is that, in many cases, the link is either rusted or damaged beyond repair. If so, we recommend replacing a faulty level sensor with an OEM Mercedes Level Sensor. If the link is not damaged, the next step is to read the fault codes using an OBD-II scanner designed for Mercedes-Benz vehicles.
The YOUCANIC Full System Scanner can read and clear fault codes through every control module on a vehicle.
Where is the Level Sensor Located on a Mercedes-Benz?
Description of Ride Height Level Sensors on vehicles with three sensors. Vehicles with four sensors have one sensor at each air strut.- B22/8 Left the front level sensor
- B22/9 Right front-level sensor
- B22/3 Rear axle level sensor
