Mercedes W221 ABS Wheel Speed Sensor Front Left Right N/O/S A2215400317

Mercedes W221 ABS Wheel Speed Sensor Front Left Right is a precision braking system component responsible for accurately reading the rotational speed of the front wheels. As part of the ABS wheel speed sensor group, it works in conjunction with the ABS/ESP module, supporting driving stability, braking efficiency, and the operation of safety systems. This used component allows for a technically correct, cost-effective repair without compromising the original performance characteristics of the system.

Specifications and technical data

• SKU: A2215400317
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2215400317
• Substitutable numbers: A2215400317, A 221 540 03 17
• Location on the vehicle: Front, Left, Right
• Category: ABS Speed Sensors

Function and role of the ABS wheel speed sensor in the Mercedes W221

The front axle speed sensor in the Mercedes W221 is responsible for generating a signal proportional to the wheel's rotational speed. This information is used by the ABS controller to:

• control wheel slip during braking,
• support the operation of electronic stability control systems,
• coordinate traction control systems during acceleration,
• monitor vehicle speed for selected comfort and safety functions.

An incorrect signal from the sensor can result in the ABS/ESP warning light illuminating, increased braking distance, and restricted operation of electronic assistance systems. Replacing it with a functional unit restores the correct logic of the system.

Vehicle placement and application

The presented sensor is designed for installation on the front axle, on either the left or right side, allowing for flexible application when repairing the braking system in the Mercedes S-Class W221 generation. This allows a single type of component to serve both sides of the vehicle, simplifying part selection and service logistics.

Correct positioning of the sensor relative to the impulse ring is crucial for a stable signal reading. Proper installation minimizes the risk of interference, diagnostic errors, and incorrect wheel speed readings.

Benefits of using an original ABS wheel speed sensor

Using an original speed sensor in the Mercedes W221 ensures:

• signal characteristic compliance with ABS/ESP controller requirements,
• stable cooperation with the factory electrical installation,
• proper geometric fit to the steering knuckle and mounts,
• preservation of the factory operating parameters of the braking system.

The used component allows for reduced repair costs while maintaining the original design and system operation. This solution is particularly beneficial for comprehensive braking system maintenance in premium class vehicles.

Professional selection and diagnostics

Before installing the sensor, it is recommended to perform computer diagnostics to confirm the source of the fault and verify the signal accuracy after replacement. It is also important to check the condition of the wiring harness, connectors, and the impulse ring on the wheel hub. A correctly selected and installed sensor reduces the risk of recurring controller errors and ensures predictable vehicle behavior during braking.

If you are planning a comprehensive repair or upgrade of the braking zone in your Mercedes and need other components from the same group, such as additional sensors, signal cables, or mounting elements, check the available parts in the Mercedes ABS wheel speed sensor category.

Used electronics and sensors – what to look for

When choosing a used ABS speed sensor, it is crucial to pay attention to the condition of the connectors, the absence of mechanical damage to the housing, and the ability to read the signal correctly during diagnostics. A properly selected component can operate long and stably, representing a reasonable compromise between cost and functionality.

To better understand when choosing used electronic components is justified and how to minimize risks when purchasing them, it is worth reading our guide: The second life of electronics – when is it worth choosing used engine controllers, comfort modules, and parking sensors?