Mercedes W221 S500 4-Matic M273.968 Engine Control Unit ECU Kit A2731536591 Key

Mercedes W221 S500 4-Matic M273.968 Engine Control Unit ECU Kit is a specialized electronic control module designed for the S-Class drivetrain with 4Matic all-wheel drive. It is responsible for the precise management of the M273.968 unit, ensuring stable engine characteristics, correct fuel delivery, and seamless integration with other vehicle systems. The kit including the key facilitates configuration in the vehicle and reduces the risk of immobilizer-related issues.

Specifications and technical data

• SKU: A2731536591-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2731536591
• Substitutable numbers: A2731536591, A 273 153 65 91, 0261209292, 0 261 209 292, A2215451108, A 221 545 11 08
• Category: ECUs & Computer Modules

Function and application of the engine control unit

The presented controller belongs to the Electronic control modules and controllers category and acts as the central unit managing the gasoline engine in the W221 generation Mercedes S-Class with all-wheel drive. The ECU analyzes sensor signals, controls fuel injection, ignition, and interacts with safety and comfort systems, which translates into predictable throttle response and proper operation of the M273.968 unit.

Thanks to its dedicated design for the specific S500 4-Matic model configuration, the module provides the correct control maps and operating logic matched to the vehicle's factory parameters. Using the appropriate ECU is crucial when replacing a faulty controller, especially in advanced Mercedes drivetrain systems.

Advantages of the ECU kit with key

A significant feature of this product is the inclusion of the kit with key, which in practice simplifies the adaptation process in the vehicle. In many Mercedes S-Class units, the engine controller is logically linked to the immobilizer system, which is why a set with a key can:

• limit the scope of necessary programming work,
• facilitate matching to the existing electrical installation,
• reduce the risk of ignition authorization problems.

For workshops specializing in the Mercedes brand and for advanced users, this means a more predictable installation and configuration process, as well as the possibility of more efficient diagnostics in the event of previous controller failures.

Technical characteristics and compatibility

As a Mercedes brand product, the engine control unit is designed for full integration with the factory electrical architecture and the vehicle's communication network. The correct OEM part number and available interchangeable numbers allow for precise matching of the module to the specific equipment version and model year, which is particularly important in S-Class models where many configuration variants exist.

Before purchasing, it is recommended to verify compatibility using the VIN and compare the controller parameters with the currently installed module. This helps avoid communication problems within the vehicle network, engine control errors, or improper operation of additional functions.

Product condition and benefits of choosing a used ECU

The offered engine control unit comes from the secondary market, which allows for a significant reduction in repair costs compared to purchasing a new module. A used controller, when properly selected and installed, can effectively restore the efficiency of the drivetrain while maintaining factory engine operating parameters.

More practical information on how to safely choose used control modules and sensors can be found in the Global Parts guide: Used automotive electronics on board – why is it worth choosing second-hand ECU modules and sensors?

Support for expanding the Mercedes control system

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other components from the same group, such as additional controllers, auxiliary modules, or powertrain management systems, check the available parts in the Mercedes electronic control modules and controllers category.

With a properly selected engine control unit for the Mercedes W221 S500 4-Matic M273.968, you can restore the proper operation of the powertrain, minimize the risk of electronic errors, and maintain the consistency of the entire control system in accordance with the manufacturer's specifications.