Mercedes W221 Anti-Theft Alarm Bracket Siren Horn Signal Holder A2215458140

Mercedes W204 Alarm Siren A2045456740 is an original part from the Horns group, designed for the factory alarm system of Mercedes vehicles. It ensures proper generation of the alarm's acoustic signal, which translates to more effective vehicle security and correct integration with the vehicle's electronics.

Specifications and technical data

• SKU: A2215458140
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2215458140
• Substitutable numbers: A2215458140, A 221 545 81 40, KD
• Category: Horns

Purpose and Function of the Alarm Siren

The alarm siren in Mercedes models is responsible for generating a clear, hard-to-ignore sound when the vehicle's security is breached. A correctly selected part from the Horns group is crucial for maintaining the full functionality of the factory alarm, including proper cooperation with the central locking, sensors, and comfort modules.

The presented alarm signal is designed as part of an OEM system, meaning it is tailored to the factory electrical installation, has appropriate acoustic parameters, and is compatible with the software of Mercedes car control units.

Construction and Fit for Mercedes Installation

The alarm siren is structurally prepared for installation in a dedicated location on the body, taking into account factory mounting points and wiring harness routing. The electrical connectors are adapted to the original Mercedes wiring harness, which simplifies installation and reduces the risk of installation errors.

By using an OEM component, the following are ensured:

• appropriate volume parameters and sound characteristics,
• correct cooperation with the factory alarm control unit,
• stable operation under typical vehicle operating conditions.

Benefits of Using an Original Alarm Siren

Using an original alarm signal in a Mercedes helps avoid problems typical of aftermarket replacements, such as incorrect error messages, interference with the comfort system, or incompatibility with control unit software. Factory fit translates to predictable operation of the security system and no need for installation modifications.

A part from this group is particularly recommended for:

• repairing a faulty or leaking alarm signal,
• restoring full functionality of the factory alarm after installation tampering,
• diagnosing faults related to the absence of alarm sound or its unstable operation.

Characteristics of a Used Product

The offered alarm signal is a used part, sourced from disassembly, which allows for compliance with the original Mercedes specification while optimizing repair costs. Such components are often chosen by workshops specializing in the Mercedes brand when they aim to maintain the vehicle's factory configuration.

Choosing a used OEM part is a sensible solution when vehicle electronics compatibility and maintaining the original alarm system operating parameters are the priority.

Related Parts and Security System Development

When replacing the alarm siren, it is advisable to check the condition of the electrical installation, connectors, and cooperating modules to ensure stable operation of the entire system. In vehicles with four-wheel drive and advanced comfort electronics, the alarm system often interacts with numerous additional sensors and control units. If you want to better understand how powertrains and electronic safety systems are integrated in premium cars, read the article xDrive, 4Matic, quattro, or 4Motion – comparison of AWD drives from BMW, Mercedes, Audi, and VW.

If you are planning a comprehensive repair or upgrade of the acoustic signaling zone in your Mercedes and need other parts from the same group, such as additional sound signals, control modules, or acoustic warning elements, check the available parts in the Mercedes Horns category.