Mercedes W164 ML 280 CDI 642.940 190HP Engine Unit ECU Kit A6421509678 Key Lock

Mercedes W164 ML 280 CDI 642.940 190HP Engine Unit ECU Kit Key Lock is a complete engine control set designed for Mercedes vehicles with a diesel engine and automatic transmission. The set includes an electronic engine control unit and the components necessary for integration with the immobilizer system and ignition switch, which facilitates matching to a specific vehicle. This solution allows for the efficient replacement of a damaged controller and restores the proper operation of the power unit.

Specifications and technical data

• SKU: A6421509678-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6421509678
• Substitutable numbers: A6421509678, A 642 150 96 78, 0281013753, 0 281 013 753, A1645451308, A 164 545 13 08
• Fuel type: Diesel
• Gearbox type: Automatic
• ECU type: Engine Control Unit
• Category: ECUs & Computer Modules

Purpose and function of the ECU kit

The engine control unit kit has been designed to work with the CDI diesel unit and automatic transmission, ensuring proper control of fuel dosage, boost pressure, and engine operating parameters. ECU type: Engine Control Unit is responsible for coordinating the operation of accessories, communicating with other modules in the vehicle, and handling anti-theft security systems. Thanks to this, the kit is particularly useful when replacing a damaged controller, where maintaining compatibility with the original vehicle configuration is necessary.

Benefits of using a complete kit

Choosing a complete ECU kit with lock and key simplifies the installation and configuration process in the vehicle. In practice, this means:

• maintaining consistency between the engine controller and the immobilizer system,
• reducing the need for advanced programming and adaptation,
• better compatibility with the electrical installation and the vehicle's CAN network,
• the possibility of faster diagnostics and starting the power unit after replacement.

For workshops and service centers specializing in the Mercedes brand, such a kit is a practical service solution that allows for shorter repair times and reduces the risk of communication problems between modules.

Characteristics of operation with a diesel engine and automatic transmission

The controller from this series is adapted to the specifics of diesel engines, where precise control of injection, fuel pressure, and cooperation with the turbocharging system is crucial. Fuel type: Diesel means that the software and operating map are adjusted to the torque characteristics and emission requirements of this unit. At the same time, transmission type: automatic requires close cooperation between the ECU and the transmission control module to ensure smooth gear changes, proper torque management, and driving comfort.

Category and application in vehicle electronics

The product belongs to the group of Electronic control modules and controllers, which are components responsible for managing key vehicle systems. In the case of this kit, the main task is to handle engine operation, communicate with other controllers, and integrate with security systems. Such components are particularly important during major power unit repairs, engine replacement, or when troubleshooting starting and communication issues in the vehicle network.

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 controllers, modules working with the engine, or related electronic systems, check the available parts in the category Mercedes electronic control modules and controllers.

Product condition and buyer tips

The ECU kit comes from the secondary market, which makes it an attractive cost-effective alternative to new components while maintaining the original manufacturer's specifications. Before installation, a standard diagnostic procedure and verification of compatibility with the specific vehicle configuration, including engine type, transmission, and additional equipment, are recommended. For best results, installation should be performed by a workshop with experience in working with Mercedes electronics and appropriate diagnostic tools.

If you want to better understand when choosing a used engine controller is justified and how to safely select such an element for your car, read our guide: The second life of electronics – when is it worth choosing used engine controllers, comfort modules, and parking sensors?

Additional practical tips on the safe purchase of used electronic components and other subassemblies online are provided in the article Safe purchase of used car parts online – a step-by-step guide, which can be helpful for both individual users and professional service centers.