Mercedes W204 S204 Estate SAM Control Unit Module Rear A2049005601

Mercedes W204 S204 Estate SAM Control Unit Module Rear is a factory-original component from the Electronic control modules and controllers group, responsible for power management and signal distribution in the rear of the vehicle. Thanks to its design tailored to the W204/S204 platform, it ensures consistency with the electrical installation and stable operation of comfort and lighting systems. This is a practical solution for users who want to restore full functionality of the electronics in their Mercedes while maintaining the original system architecture.

Specifications and technical data

• SKU: A2049005601
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2049005601
• Substitutable numbers: A2049005601, A 204 900 56 01
• Location on the vehicle: Rear
• Category: ECUs & Computer Modules

Function of the SAM module in the rear of the vehicle

The SAM module integrated with the fuse box in the rear area of the body is responsible for logical control and protection of many electrical circuits. In practice, this means controlling the power supply to receivers located at the rear of the car, monitoring the load on individual lines, and protecting the installation against overload. Such an architecture allows for quick fault localization and reduces the risk of damage to other electronic components.

Benefits of using the original module in the Mercedes W204/S204

Using the original SAM module in the W204/S204 estate ensures:

• Full compatibility with the factory installation – maintaining the original control logic and communication within the vehicle network.
• Stable operation of electrical systems in the rear of the car – lower risk of errors and fault messages.
• Simplified diagnostics – module parameters are recognized by factory service tools.
• Consistency with service documentation – easier testing and service procedures.

As a result, the module aligns with the manufacturer's requirements for safety and reliability of electrical systems, which is particularly important for daily vehicle operation.

Vehicle placement and installation aspects

The component is designed to operate in the rear of the vehicle, which translates into appropriate placement of connectors, fuse sockets, and mounting points. Such placement:

• shortens the length of wiring harnesses leading to receivers at the rear of the car,
• facilitates service access to fuses and connectors,
• limits interference with other areas of the installation during replacement.

During installation, it is recommended to follow the manufacturer's procedures, including the correct sequence of disconnecting and connecting the power supply, as well as checking the condition of harnesses and connectors. This minimizes the risk of recurring faults and ensures proper cooperation of the module with other controllers in the vehicle.

Using a pre-owned electronic module

Choosing a pre-owned module from the Electronic control modules and controllers group is a reasonable way to reduce repair costs while maintaining the original part specification. In practice, with correct selection based on manufacturer markings and compatibility verification, such a component can effectively restore the efficiency of electrical systems without the need to invest in a new part. It is important to check the condition of the connectors before installation and, if necessary, perform diagnostics using an appropriate tester.

If you want to better understand what to look for when buying and installing pre-owned controllers and how to safely select them based on manufacturer markings and hardware parameters, check out our guide: Used automotive electronics – ECU modules and sensors from the secondary market.

Expanding the control system in your Mercedes

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