Mercedes W164 ML320 CDI OM642.940 Engine Module ECU Kit A6421506491 + 2 Keys

Mercedes W164 ML320 CDI OM642.940 Engine Module ECU Kit is a control set designed for the Mercedes M-Class powertrain, including the ECU engine module and two keys. This set from the Electronic control modules and controllers category allows for professional replacement of the vehicle's control unit, maintaining electronic consistency and a high level of safety. It is a practical solution for workshops and users who need a verified, used module for advanced diagnostics or repairs.

Specifications and technical data

• SKU: A6421506491-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6421506491
• Substitutable numbers: A6421506491, A 642 150 64 91, 0281013382, 0 281 013 382, A1645450708, A 164 545 07 08, KZ
• Category: ECUs & Computer Modules

Application and function of the ECU kit

The presented engine control unit kit is designed for the OM642.940 diesel engine in the Mercedes W164 ML320 CDI model. The ECU module is responsible for precise engine management, including fuel injection, boost control, starting strategies, and cooperation with other vehicle systems. The inclusion of two keys in the set facilitates integration with the immobilizer and security system, which is particularly important when replacing electronics in modern vehicles.

Benefits of choosing a used control module

Choosing a used ECU kit for a Mercedes allows for a significant reduction in repair costs while maintaining factory control logic. An original module from a vehicle of the same engine family ensures high compatibility with the electrical installation and vehicle software. For workshops, this means shorter diagnostic time, easier adaptation, and a lower risk of communication issues within the CAN network.

A used control module is also a good solution in situations where the factory ECU has suffered thermal damage, water ingress, or internal electronic failure. Using a complete kit with keys helps limit the need for deep interference with security systems, which speeds up the process of restoring the vehicle to full functionality.

Professional installation and technical aspects

To fully utilize the potential of this kit, installation in a specialized service center equipped with appropriate Mercedes diagnostic software is recommended. Proper installation includes:

• verification of engine unit and vehicle model year compatibility,
• inspection of the electrical installation for previous damage,
• adaptation procedures and potential module coding in the vehicle,
• road tests with engine parameter readings.

Such an approach minimizes the risk of communication errors, starting issues, or warning lights. For the user, this means stable engine operation and predictable vehicle behavior under various operating conditions.

Selection support and technical knowledge

When selecting engine electronics, it is crucial to match the OEM number and interchangeable numbers, as well as consider the software version. A detailed discussion of selection principles, hardware and software compatibility issues, and practical installation examples can be found in the Global Parts guide: Used automotive electronics – ECU modules and sensors from the secondary market. This is a valuable source of knowledge for both professional services and informed users.

Expanding Mercedes electronics upgrades

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, comfort modules, or assistance system controllers, check the available parts in the Mercedes electronic control modules and controllers category.

This allows you to plan the replacement of several related components in one stage, which facilitates repair project management and allows for better control over the compatibility of the entire electronic system in the vehicle.