Mercedes W205 W213 ABS Wheel Speed Sensor Rear Left Right N/O/S A2139055703

Mercedes W205 W213 ABS Wheel Speed Sensor Rear Left Right is an original wheel speed measurement component designed for installation on the rear axle of Mercedes vehicles. The ABS speed sensor is responsible for precisely transmitting the signal to the control unit, which ensures stable operation of the anti-lock braking system and improves safety during braking.

Specifications and technical data

• SKU: A2139055703
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2139055703
• Substitutable numbers: A2139055703, A 213 905 57 03
• Location on the vehicle: Rear, Right, Left
• Category: ABS Speed Sensors

Function and application of the ABS speed sensor

The ABS speed sensor mounted on the rear axle, on either the left or right side, works with the wheel impulse ring to generate a rotational speed signal. Based on this data, the brake system control unit regulates pressure in the circuits, limiting wheel lock-up and improving vehicle stability on surfaces with varying grip.

Thanks to accurate wheel speed readings, assistance systems such as ABS or other stability control systems can operate in a predictable and repeatable manner. A correctly selected rear axle sensor is particularly important during emergency braking, trailer towing, or driving in difficult road conditions.

Compatibility and vehicle placement

The presented item belongs to the ABS speed sensor category and is designed for installation on the rear axle of the vehicle, on both the right and left sides. This solution facilitates part selection during service – one type of sensor can be used on both sides, which simplifies logistics and reduces the risk of ordering errors.

The placement on the vehicle is designed to ensure stable mounting and the correct operating distance from the impulse ring. Proper cable routing and correct seating of the electrical connector are crucial for maintaining resistance to interference and for long-term, repeatable sensor operation.

Characteristics of the original Mercedes part

The ABS speed sensor used in Mercedes W205 and W213 models is a component that complies with the vehicle manufacturer's requirements. This means matched electrical characteristics, the appropriate cable length, and the correct connector type, which translates into seamless integration with the factory wiring harness.

The original design ensures:

• a stable wheel speed signal across the full range of vehicle speeds,
• resistance to typical operational loads in the wheel arch and suspension zone,
• proper cooperation with the factory brake system control unit.

Condition of the component and installation aspects

The offered ABS speed sensor is a pre-owned component, which allows for an economical repair of the braking system while maintaining compliance with factory specifications. Replacing the sensor is a typical service operation, most often performed when ABS system errors appear, a warning light illuminates on the instrument cluster, or a wheel speed reading is lost.

During installation, it is recommended to thoroughly clean the socket in the steering knuckle and check the condition of the cable and connector. Proper cable routing in the holders minimizes the risk of mechanical damage and the influence of contaminants, which is important for long-term, stable system operation.

System expansion and electronics selection

In vehicles equipped with advanced driver assistance systems, the ABS speed sensor works with many electronic modules. When planning a repair, it is worth considering the general condition of the vehicle's electronics and how to select used components. Practical tips on choosing and verifying electronic elements can be found in the article The second life of electronics – when is it worth choosing used engine controllers, comfort modules, and parking sensors?.

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 cables, or mounting elements, check the available parts in the Mercedes ABS speed sensor category.