Mercedes W251 R 320 CDI 642.950 224HP Engine ECU Kit A6421506434 Keys Lock

Mercedes W251 R 320 CDI 642.950 224HP Engine ECU Kit is a specialized module from the Electronic control modules and controllers category, designed for precise management of the diesel powertrain paired with an automatic transmission. It is responsible for advanced control of diesel engine parameters, ensuring stable operation, correct fuel dosage, and proper communication with other vehicle systems.

Specifications and technical data

• SKU: A6421506434-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6421506434
• Substitutable numbers: A6421506434, A 642 150 64 34, 0281014940, 0 281 014 940, A1645451508, A 164 545 15 08
• Fuel type: Diesel
• Gearbox type: Automatic
• Category: ECUs & Computer Modules

Purpose and function of the engine control unit

The presented engine computer is designed to work with the diesel power unit in the Mercedes R-Class W251 series, specifically the R320 CDI model with 224 HP. The module plays a key role in controlling injection, turbocharging, auxiliary equipment, and monitoring operational parameters, which translates into smooth acceleration, predictable throttle response, and optimized fuel consumption.

The controller is adapted to work with an automatic transmission, allowing it to correctly exchange data with the transmission module, traction control system, and other control units in the vehicle. Proper software configuration allows for the preservation of the factory performance characteristics of the drivetrain.

Benefits of using an original module

Using an original engine control unit in a Mercedes W251 R320 CDI ensures:

• preservation of the factory control logic for the powertrain,
• consistency of communication within the vehicle network with other electronic modules,
• possibility of correct diagnostics using professional service testers,
• stable operation across a wide range of loads and temperatures.

For the user, this means more predictable vehicle behavior, reduced risk of communication errors between modules, and easier service maintenance. For diesel units, precise control of injection and turbocharging is particularly important – a fully functional engine control unit has a direct impact on engine refinement, dynamics, and exhaust emissions.

Technical characteristics and compatibility

The module belongs to the Electronic control modules and controllers category, meaning it is a central element for managing the engine and its accessories. Its adaptation for diesel fuel and compatibility with an automatic transmission make it a solution dedicated to a specific drivetrain configuration, and its selection should always be verified for vehicle compatibility.

In practice, when selecting a controller, it is worth using the OEM part number and interchangeable numbers, as well as vehicle data (VIN), to confirm full hardware and software compatibility. This minimizes the risk of engine starting problems, CAN communication errors, or malfunctions of driver assistance systems.

Condition, installation, and practical aspects

The offered controller is a secondary market component, which allows for significant repair cost savings compared to purchasing a brand-new module. Before installation, it is recommended to perform standard service procedures, such as verifying compatibility, potential software matching, and adaptation to the specific vehicle in accordance with the manufacturer's procedures.

Professional installation and configuration are particularly important in modern diesel units, where the engine computer interacts with many safety and comfort systems. A correctly selected and configured controller allows for the restoration of full drivetrain functionality after a previous module failure, without the need for costly replacement of entire wiring harnesses or additional components.

Control system expansion and additional information

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

When selecting a used engine computer, a guide on secondary market electronics can be particularly helpful – issues such as selection by VIN or OEM number, hardware and software compatibility, or installation procedures are discussed there step by step. You can find more practical tips in the article Used automotive electronics on board – why is it worth choosing second-hand ECU modules and sensors?.