Mercedes S212 Estate Fuse Box Rear SAM Module Relay Control Unit A2129004201

Mercedes S212 Estate Fuse Box Rear SAM Module Relay Control Unit is an advanced rear power management module responsible for power distribution and protection of electrical circuits in the vehicle. As an element of the Fuses and fuse boxes group, it ensures organized wiring management and stable operation of numerous electrical consumers. This used SAM module is a solution that allows for the technical repair of the electrical system while maintaining cost-effective service expenses.

Specifications and technical data

• SKU: A2129004201
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2129004201
• Substitutable numbers: A2129004201, A 212 900 42 01, 5DK009620-37, 5DK 009 620-37
• Location on the vehicle: Rear
• Category: Fuses & Fuse Boxes

Function of the SAM module in the Mercedes S212

The rear SAM module acts as a central point for power distribution and control of selected electrical circuits located at the rear of the vehicle. It is responsible, among other things, for powering and protecting systems such as rear lighting, selected comfort features, or additional consumers mounted in the trunk. Thanks to its integrated design, it reduces the number of individual wires and connections, which positively impacts the reliability of the installation.

Proper selection of the module for a specific version of the Mercedes allows for restoring the correct operation of the electrical system after fuse failure, damage to the fuse box, or problems with the power supply of individual circuits. This is particularly important in modern vehicles, where voltage stability and proper protection of power lines have a direct impact on the operation of comfort and safety systems.

Construction and purpose of the rear fuse box

The presented item belongs to the Fuses and fuse boxes category, which means it combines the function of a fuse carrier and a control module. Its location in the rear part of the vehicle facilitates service access to the circuit protections associated with the rear body zone, without the need to interfere with the front installation.

Such a design solution allows for:

• clear separation of front and rear circuits,
• shortening the length of electrical harnesses in the rear of the car,
• easier diagnostics of faults related to power supply,
• efficient replacement of the entire module in case of mechanical or thermal damage.

Selection, compatibility, and technical aspects

For the SAM module to work correctly, it is crucial to match it to the specific equipment configuration of the vehicle. The product has a dedicated OEM part number and interchangeable numbers, which enable precise identification and comparison with the factory-installed component. This allows for verifying compatibility with a given Mercedes version, minimizing the risk of communication problems in the electrical system.

In practice, this means that before installation, it is worth comparing the markings on the module housing with the vehicle data and consulting the selection with the manufacturer's catalog or a specialized service center. This approach allows you to utilize the module's potential and ensure stable operation of the electrical system after replacement.

Condition, installation, and service application

The offered SAM module is a used component, which in practice provides a favorable compromise between repair cost and functionality. This type of part is particularly useful in situations where the original fuse box has been damaged, contacts have overheated, or an electronic failure has occurred in the rear part of the installation. Replacing the complete module often shortens repair time compared to attempts to regenerate a damaged unit.

Due to its location in the rear zone of the vehicle, installation requires access to the luggage compartment and maintaining the correct sequence of connecting connectors and fuses. It is recommended that installation work be performed by an automotive electrician or a workshop experienced with Mercedes installations, which limits the risk of errors and ensures safe system startup.

System expansion and additional information

If you are planning a comprehensive repair or modernization of the electrical zone in your Mercedes and need other elements from the same group, such as additional fuse boxes, power distribution modules, or fuse housings, check the available parts in the Mercedes Fuses and fuse boxes category.

For drivers who want to better plan their car service and optimally allocate their repair budget, a guide describing the most frequently replaced maintenance components may be helpful – you can find practical tips in the article TOP 10 most frequently replaced parts in your car.