Mercedes Vito Viano W639 ABS Sensor Rear Axle Brake Speed Sensor A6395400917

Mercedes Vito Viano W639 ABS Sensor Rear Axle Brake Speed Sensor is a precision brake system component responsible for accurate wheel speed readings on the rear axle. As part of the ABS speed sensor group, it works with the ABS control module to stabilize braking performance and support driving safety. This original used component is a sensible choice for drivers looking for a technically verified solution at an attractive price.

Specifications and technical data

• SKU: A6395400917
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6395400917
• Substitutable numbers: A6395400917, A 639 540 09 17, KD
• Location on the vehicle: Rear
• Category: ABS Speed Sensors

Purpose and function in the brake system

The offered sensor is dedicated to the rear of the vehicle, where it monitors wheel rotation speed and transmits a signal to the ABS controller. This allows the system to limit wheel slip during braking, improving directional stability and vehicle control in emergency situations. Precise speed reading is crucial for the proper operation of assistance systems such as ABS or advanced traction control systems.

Benefits of using an original sensor

Choosing an original speed sensor for the rear axle of a Mercedes Vito W639 ensures:

• consistency of electrical parameters and signal with the factory ABS controller,
• correct geometric fit to the steering knuckle and wheel hub,
• stable operation of the brake system without the need for additional adaptations.

Such a solution minimizes the risk of diagnostic errors, ABS/ESP warning lights, and malfunctions of safety systems. A properly selected ABS speed sensor allows for restoring full system functionality after repairs or replacement of rear suspension components.

Installation characteristics of the rear ABS sensor

The sensor designed for the rear of the vehicle is structurally adapted to operate in harsh conditions – near the wheel hub, where dirt, moisture, and variable temperatures occur. The appropriate shape of the housing and mounting points facilitates installation in the factory socket, and correct positioning relative to the impulse ring guarantees a stable signal. Proper placement on the vehicle has a direct impact on the quality of the reading and the durability of the component.

Why choose a used ABS sensor

A used ABS speed sensor for a Mercedes is a solution that allows you to optimize service costs while maintaining a high-quality component. A part sourced from a factory system disassembly often features better fitment than cheap aftermarket replacements of unknown origin. For many fleet users and workshops specializing in the Mercedes brand, this is a practical way to perform a quick and effective brake system repair.

If you want to better understand how to safely select and install used electronic components and sensors in a car, it is worth checking out the Global Parts guide: Used automotive electronics on board – why is it worth choosing ECU modules and sensors second-hand?

Expanding ABS system service in a Mercedes

When working on the rear axle and brake system, it is worth paying attention to the condition of wires, connectors, and other elements responsible for wheel speed readings. A consistent service approach reduces the risk of the fault returning and shortens future diagnostic time. If you are planning a comprehensive repair or upgrade of the braking zone in your Mercedes and need other elements from the same group, such as additional sensors, signal wires, or mounting elements, check the available parts in the Mercedes ABS speed sensor category.