Mercedes W169 W203 W204 W211 OBD Diagnostic Plug Cover A2025402373

Mercedes W169 W203 W204 W211 OBD Diagnostic Plug Cover is a precision service component that ensures stable mounting of the diagnostic connector in Mercedes vehicles. A properly selected housing protects the OBD plug from mechanical damage, facilitates the connection of testers, and supports trouble-free vehicle electronics diagnostics.

Specifications and technical data

• SKU: A2025402373
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2025402373
• Substitutable numbers: A2025402373, A 2025402373, A 202 540 23 73
• Category: Other Starters, Alternators, ECUs & Wiring

Purpose and function of the OBD socket housing

The diagnostic socket housing in Mercedes A-Class and C-Class models is responsible for the stable seating of the OBD connector in the console or the lower part of the dashboard. A correctly installed part:

• maintains the connector in a fixed position, which prevents looseness when connecting a diagnostic interface,
• reduces the risk of pulling out wires during frequent servicing,
• organizes the mounting space around the electrical harness,
• ensures easy access to the socket for a mechanic or diagnostician.

Thanks to this, controller diagnostics, error reading, and software updates can be performed efficiently and without additional problems associated with a loose or damaged socket.

Construction and technical features

The OBD diagnostic plug cover has been designed as a dedicated mounting element for installation in specific body points. The design provides:

• a profile matched to the shape of the factory OBD socket used in Mercedes vehicles,
• slots for clips or mounting screws, allowing for secure attachment within the interior structure,
• a guide opening that positions the connector in the correct direction relative to the user.

Such a solution minimizes stress on the wire harness and reduces the possibility of the plug becoming misaligned when connecting diagnostic devices.

Condition, fitment, and service application

The offered housing comes from dismantling, which allows for maintaining the original mounting geometry consistent with factory Mercedes standards. This is particularly important in the case of components related to diagnostics, where even minor deviations can hinder access to the socket.

The element will prove useful in situations where:

• the factory housing has been mechanically damaged (cracks, broken clips),
• the OBD socket is "hanging" on the wires and requires re-securing,
• a repair or reconstruction of an interior section is being carried out after a collision or interference with the electrical installation.

Using the original housing allows for restoring the correct mounting layout without the need to create makeshift fasteners.

Benefits of using the original OBD housing

Choosing a dedicated diagnostic socket housing brings tangible operational benefits:

• Safer tester connection – the connector is stable, which reduces the risk of damaging the pins.
• Better service ergonomics – the mechanic quickly locates and connects the interface without searching for a loosely hanging plug.
• Interior aesthetics – the socket is integrated into the trim elements without visible modifications.
• Reduced stress on the harness – proper wire routing extends the service life of the installation.

Additional information and related categories

If you are planning a comprehensive repair or upgrade of the diagnostic area in your Mercedes and need other elements from the same group, such as socket holders, mounting covers, or small fastening components, check the available parts in the Other Mercedes category.

For a comparison of solutions used in sports models of other brands and a better understanding of the differences in the construction of drive and brake systems, you can read the article on our blog: Audi RS vs other models – what is hidden under the hood and chassis?.