Mercedes W204 S204 Estate Rear SAM Control Unit Module A2049001202

Mercedes W204 S204 Estate Rear SAM Control Unit Module is an advanced component from the Electronic control modules and controllers category, responsible for managing selected electrical functions in the rear part of the vehicle. It is designed for installation in the W204/S204 estate body style, ensuring consistent circuit management and stable operation of comfort and lighting systems.

Specifications and technical data

• SKU: A2049001202
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2049001202
• Substitutable numbers: A2049001202, A 204 900 12 02, 5DK009225-58, 5DK 009 225-58
• Location on the vehicle: Rear
• Category: ECUs & Computer Modules

Purpose and function of the SAM module

The described SAM control unit has been specifically designed for use in the rear of the estate body, where it is responsible for the logical control of selected electrical circuits. It integrates monitoring, power distribution, and communication functions with other vehicle control units into a single housing, which helps reduce the number of individual relays and fuses scattered throughout the car.

Thanks to this solution, the electrical system is more organized, and fault diagnostics are faster and clearer. The module communicates with the vehicle's communication bus, transmitting information to other control units and responding to their commands in real time.

Benefits of using an original control unit

Using an original SAM module dedicated to the W204/S204 series allows you to maintain the factory logic of the electrical systems. This means:

• proper compatibility with the electrical installation and other control units,
• consistent operation of comfort and lighting functions in the rear of the vehicle,
• easier diagnostics using factory service tools,
• reduced risk of communication errors in the vehicle network.

A used component of this type is an attractive alternative to a new part, especially in the case of post-accident repairs or restoring full system functionality after mechanical damage or water ingress.

Installation and vehicle integration

The module is designed for installation in the rear area of the body, in the location provided by the manufacturer. Thanks to the factory wiring harness connectors, installation is limited to correctly seating the control unit and connecting the appropriate plugs, without the need for any modifications to the installation.

When replacing, it is recommended to:

• thoroughly check the condition of the harnesses and connectors for corrosion and mechanical damage,
• perform computer diagnostics after installation,
• verify the correct operation of all functions managed by the module in the rear of the vehicle.

Application in service practice

The SAM control unit in the W204/S204 estate is often replaced when there are problems with rear lighting, the tailgate central locking, or other electrical functions located in the rear of the car. In many cases, replacing the complete control unit is a faster and more predictable solution than repairing an extensive wiring harness or individual circuits.

By choosing this component, you gain the ability to restore the correct operation of systems without interfering with the factory electrical architecture, which is important both for the durability of the repair and the future resale value of the vehicle.

If you are planning a comprehensive repair or upgrade of the electrical system in your Mercedes and need other components from the same group, such as additional controllers, comfort modules, or lighting management units, check out the available parts in the Mercedes electronic control modules and controllers category.

More about electronic modules and used parts

When working with advanced automotive electronics, it is worth knowing best practices regarding diagnostics, coding, and selecting parts from dismantling. In the context of control modules, comfort systems, or multimedia units, a guide describing the handling of similar solutions in other brands may be helpful – you can find it in the article Driving pleasure for years – how to take care of iDrive systems and electronic modules in BMW 3 and 5 series models.

If you want to better understand why used control units and other vehicle electronics can be a reasonable, technically justified choice, it is worth reading the material Used car parts: Myths and facts you need to know, which discusses the most common doubts related to parts from dismantling in an accessible way.