Mercedes R171 W203 W209 W639 Coolant Level Indicator Sensor Switch A2205450024

Mercedes Coolant Level Sensor is a component from the Temperature Sensors category, designed for cooling systems in Mercedes R171, W203, W209, and W639 models. It is responsible for reliably monitoring the coolant level and transmitting a signal to the vehicle's electrical system, ensuring safe and stable engine operation.

Specifications and technical data

• SKU: A2205450024
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2035451024
• Substitutable numbers: A2035451024, A 203 545 10 24
• Category: Temperature Sensors

Application and Function in the Cooling System

The Coolant Level Sensor works with the vehicle's electrical system, monitoring the presence of coolant in the reservoir or cooling circuit. If the coolant level drops, it sends a signal to the instrument cluster or control module, allowing the driver to react quickly and reduce the risk of engine overheating.

This component is designed for Mercedes vehicles from the R171, W203, W209, and W639 series, where the cooling system requires precise coolant level monitoring. As a result, the sensor supports stable engine operating temperatures and the correct functioning of related electronic systems.

Compatibility and Part Identification

The presented sensor belongs to the group of genuine Mercedes components, which facilitates its identification and selection for a specific vehicle configuration. The part has a dedicated OEM number and interchangeable numbers that allow for unambiguous integration with the factory installation without the need for modifications to the wiring harness or reservoir.

For certainty in selection, it is recommended to verify compatibility using the OEM number or the vehicle's VIN in the manufacturer's catalog or at a professional service center. This approach minimizes the risk of installing an incorrect sensor and ensures proper interaction with the onboard electronics.

Performance Characteristics and Installation

The coolant level sensor is an electrical component operating in an environment with variable temperature and humidity, so its construction is adapted for contact with coolant and for operation within the engine bay. The design solutions used ensure a stable output signal and resistance to typical operational loads.

In most configurations, sensor installation is a plug-and-play process: after disconnecting the old component and unplugging the electrical connector, the new sensor can be seated in the reservoir's socket or the designated location in the cooling system, and then connected to the existing wiring harness. A correctly selected component does not require additional adapters or installation modifications.

Condition, Origin, and Benefits of Choosing a Used Sensor

The offered sensor comes from the group of used Mercedes parts, allowing for a reasonable cost while maintaining factory specifications. In practice, this means the possibility of restoring full cooling system functionality without the need to invest in a new component, while preserving the original operating characteristics.

A used coolant level sensor is a particularly attractive solution for maintenance repairs where compliance with the factory installation is a priority, rather than modifications or tuning. A correctly selected component allows for the proper operation of warning lights and the logic of systems that protect the engine from overheating.

More Mercedes Temperature Sensors and Technical Knowledge

If you are looking for other Mercedes Temperature Sensors for your vehicle, check out our dedicated category: Mercedes Temperature Sensors. There you will find a wide selection of components for various models, making it easier to assemble a complete set of cooling system and electronics components.

When planning to purchase a used sensor, it is worth learning about best practices for selecting and installing automotive electronics. A detailed discussion can be found in the guide: Used Automotive Electronics – Why Choose Used ECUs and Sensors, which describes, among other things, selection by OEM number, compatibility issues, and the most common questions related to installing such components.