Smart Fortwo C451 ABS Rotational Speed Sensor Rear Left N/S A4515400017

Smart Fortwo C451 ABS Rotational Speed Sensor Rear Left N/S is a precision brake system component responsible for reliable wheel speed readings and the proper operation of the ABS system. Thanks to its dedicated fitment for the rear left axle, it ensures stable performance of the braking control electronics, which translates into safer and more predictable vehicle behavior on the road. This is a solution for users who expect consistent cooperation with the factory safety system in their Smart Fortwo C451.

Specifications and technical data

• SKU: A4515400017
• Mark: Smart
• Condition: Used
• OEM Part Number: A4515400017
• Substitutable numbers: A4515400017, A 451 540 00 17
• Location on the vehicle: Rear, Left
• Category: Other Brake Parts

Purpose and function in the ABS system

The presented rotational speed sensor is designed for installation on the rear left axle of the Smart Fortwo C451 model. Its task is to generate a wheel speed signal, which is then sent to the ABS controller. Based on this data, the system can limit wheel slip, stabilize the vehicle's path, and support the driver during heavy braking, especially on surfaces with varying grip.

The dedicated placement on the vehicle allows for maintaining the correct mounting geometry relative to the impulse ring, which is crucial for the vehicle's electronics to interpret the signal correctly. As a result, the braking system maintains repeatable performance parameters, and the ABS system reacts in a predictable manner consistent with the manufacturer's specifications.

Compatibility and fitment for Smart Fortwo C451

The sensor has been designed with the Smart Fortwo C451 construction in mind, which means the shape, cable length, and electrical connector are perfectly matched to the vehicle's factory wiring harness. This solution reduces the risk of installation issues and eliminates the need for wiring modifications, with the installation itself limited to properly seating the sensor in the steering knuckle and connecting it to the original plug.

Proper fitment for the specific Smart model helps maintain the integrity of the entire braking system and facilitates diagnostics – the sensor's operating parameters fall within the range specified by the manufacturer, which helps avoid ABS controller errors resulting from an incorrect signal.

Component characteristics and benefits of use

As a safety system component, the Smart Fortwo C451 ABS Rotational Speed Sensor Rear Left N/S operates in demanding conditions – near the wheel, exposed to moisture, contaminants, and temperature fluctuations. A design adapted to this environment allows for stable signal generation, and proper seating in the socket minimizes the risk of mechanical damage.

Using this sensor allows you to:

• restore proper ABS system operation after a failure or errors related to wheel speed readings,
• maintain uniform braking system performance on the rear axle,
• reduce the risk of warning lights appearing on the dashboard,
• maintain compliance with the factory controller parameters in your Smart vehicle.

Component condition and service application

The offered sensor is a used part, making it an attractive solution for users looking for a compromise between repair costs and maintaining compliance with factory specifications. In practice, this allows for an economical replacement of a damaged sensor while maintaining proper cooperation with the existing electrical installation and the ABS controller.

Replacing the sensor is particularly recommended in situations where diagnostic errors related to the rear left wheel speed, ABS, or traction control issues occur. A correctly selected and installed component restores system stability and improves driving comfort in emergency braking conditions.

System expansion and related components

If you are planning a comprehensive repair or upgrade of the braking zone in your Smart and need other components from the same group, such as additional ABS sensors, signal cables, or mounts, check out the available parts in the Other Smart category.

To compare solutions used in different brands and vehicle segments, including sports designs with advanced braking systems, it is worth reading the analysis of systems used in high-performance models – you can find a practical summary in the article Audi RS vs other models – what is hidden under the hood and chassis?, which discusses, among other things, the differences in brake and chassis construction.