Mercedes W205 Steering Wheel Switch Button Left N/S Control Unit A0999051404

Visual condition of the part 

The product shows signs of use visible in the photos. 

Mercedes W205 Steering Wheel Switch Button Left N/S Control Unit is an original control component designed for installation on the left side of the steering wheel rim. This specialized button module ensures precise operation of vehicle functions from the steering wheel, maintaining factory ergonomics, a consistent interior look, and full integration with the Mercedes electrical system.

Specifications and technical data

• SKU: rhd-A0999051404
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A0999051404
• Substitutable numbers: A0999051404, A 099 905 14 04
• Location on the vehicle: Left
• Category: Switches & Controls

Purpose and function of the control element

The presented left steering wheel switch is part of the Switches, control elements and ignition locks group, responsible for convenient control of selected vehicle systems without taking your hands off the steering wheel. Its placement on the left side of the rim provides intuitive access to key functions, which improves driving comfort and supports safe vehicle operation.

The module is designed as a factory component for Mercedes models, ensuring proper fit to the steering wheel shape, appropriate button travel, and compatibility with the original vehicle wiring harnesses and control units.

Construction and integration with the steering system

The left steering wheel button panel in the Mercedes W205 is an integrated control unit that communicates with the vehicle's electronics via a dedicated connector. The module's design provides:

• precise fitment with the steering wheel spokes,
• stable mounting in factory installation points,
• a button layout optimized for the ergonomics of the driver's hands,
• manufacturer-designed signal logic for onboard systems.

This type of solution allows for maintaining consistent operation of all functions assigned to the left side of the steering wheel, without the need for installation modifications or the adaptation of non-original components.

Benefits of using an original used module

Choosing an original, used steering wheel switch for the Mercedes W205 is a sensible compromise between quality and cost. The factory module retains the correct electrical and mechanical parameters while allowing for cost savings compared to a new part. This allows you to restore full steering wheel control functionality while maintaining compliance with safety and comfort systems.

The original button panel is particularly recommended for:

• repairs following mechanical damage to the steering wheel,
• restoring functionality after individual button failures,
• comprehensive interior restoration when maintaining the factory standard of workmanship is a priority.

Application in service practice

The Mercedes W205 Steering Wheel Switch Button Left N/S Control Unit is suitable for both professional service centers and workshops specializing in the Mercedes brand, where installation repeatability and predictable component behavior within the vehicle's electronic system are essential. Using an original module reduces the risk of communication errors in the vehicle network and facilitates diagnostics during future inspections.

If you are planning a comprehensive repair or upgrade of the steering wheel control zone in your Mercedes and need other elements from the same group, such as additional button panels, control modules, or ignition lock components, check the available parts in the Mercedes switches, control elements and ignition locks category.

Why choose original used Mercedes parts

In the case of premium vehicles such as Mercedes, using original components – even in a used condition – allows you to maintain the proper standard of comfort and safety system operation. This applies to both mechanical elements and electronic control modules, including steering wheel switches.

To better understand the advantages of using original dismantled components in cars of this brand, it is worth reading the article Used parts for Mercedes – original dismantled parts, which discusses the practical aspects of selecting and using such elements in everyday driving.