Mercedes W164 ML320 OM642.940 224 HP 4Matic Engine ECU Kit A6421509478 Automatic

Mercedes W164 OM642.940 224HP Engine Computer Set A6421509478 Automatic is a complete engine control unit set designed for diesel engines paired with an automatic transmission. It offers precise engine management, ensuring stable power characteristics, correct transmission cooperation, and compatibility with the vehicle's factory electrical architecture. This makes it a functional service solution for advanced Mercedes powertrains.

Specifications and technical data

• SKU: A6421509478-3
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6421509478
• Substitutable numbers: A6421509478, A 642 150 94 78, 0 281 013 757, 0281013757, A1645451308, 1645451308, A 164 545 13 08
• Fuel type: Diesel
• Gearbox type: Automatic
• ECU type: Engine Control Unit
• Category: ECUs & Computer Modules

ECU Set Purpose and Function

The presented set from the Electronic Control Modules and Controllers category is responsible for the central control of diesel engine operating parameters in Mercedes W164 models with the OM642.940 224 HP unit. As an Engine Control Unit, it coordinates, among other things, fuel injection, boost control, auxiliary equipment operation, and communication with other modules in the vehicle, which translates to proper powertrain dynamics, smooth operation, and safety.

Cooperation with Diesel Engine and Automatic Transmission

The system is designed to work with Diesel fuel type engines, meaning it has tailored injection maps, boost pressure control logic, and support for sensors and actuators characteristic of this unit. Its use in a vehicle equipped with an automatic transmission ensures proper data exchange between the engine computer and the transmission module, which is crucial for smooth gear changes, throttle response, and protection of powertrain components.

Benefits of Using an Original Mercedes Module

As a Mercedes branded component, the ECU set is structurally matched to the vehicle's factory electrical system and communication bus. In practice, this means:

• maintaining the original engine and auxiliary equipment control logic,
• compatibility with safety and comfort systems,
• diagnosability using standard service tools,
• reduced risk of software compatibility issues.

For the user, this translates to predictable vehicle behavior after repair and easier future servicing.

Product Characteristics and Service Application

The offered engine computer set is a used component, allowing for an economical restoration of the powertrain's functionality while maintaining the original manufacturer's specifications. This type of solution is particularly useful in situations where the existing module has suffered electronic damage, there are communication problems within the vehicle network, or the controller needs replacement as part of an advanced engine repair.

Due to the system's complexity, it is advisable to entrust the installation and configuration of the set to a workshop experienced in working with Mercedes electronics and equipped with appropriate diagnostic software, which facilitates module adaptation to a specific vehicle instance.

Selection, Compatibility, and Practical Tips

When selecting such a set, it is crucial to pay attention to compatibility with the specific engine version, transmission type, and the vehicle's electrical architecture. Manufacturer markings and cross-reference numbers assigned to the specific controller are helpful here. A correctly selected module minimizes the risk of communication errors, starting problems, or incorrect auxiliary equipment operation.

If you want to better understand how to safely choose used controllers and other vehicle electronics components, it is worth reading a guide describing selection by VIN/OEM, hardware and software compatibility issues, and common user questions – you can find it in the article Used Car Electronics Onboard – Why Choose Second-Hand ECU Modules and Sensors?.

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