Mercedes C218 CLS 350 CDI OM642.853 265HP Engine ECU Unit A6421508900 Automatic

Engine Control Unit (ECU) kit for Mercedes W204 C350 CDI OM642.834 265 HP with automatic transmission is a specialized set from the Electronic Control Modules and Controllers category, designed for advanced engine management. This solution is dedicated to diesel engines, allowing for the restoration of correct control, stable power, and proper cooperation with the automatic gearbox.

Specifications and technical data

• SKU: A6421508900-10
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6421508900
• Substitutable numbers: A6421508900, A 642 150 89 00, 0281016656, 0 281 016 656, A2079052600, A 207 905 26 00
• Fuel type: Diesel
• Gearbox type: Automatic
• ECU type: Engine Control Unit
• Category: ECUs & Computer Modules

ECU Kit Purpose and Function

The presented ECU kit is designed to work with the OM642.834 engine, producing 265 HP, in the Mercedes C-Class W204 generation, specifically the C350 CDI version with an automatic transmission. As an Engine Control Unit, it is responsible for precise control of fuel injection, turbocharging, fuel quantity, and torque, as well as communication with other vehicle modules. In a diesel-powered vehicle, a correctly selected engine controller is crucial for:

• stable engine operation across the full RPM range,
• maintaining appropriate combustion parameters and performance,
• cooperation with the automatic transmission and safety systems.

Benefits of Using a Used ECU Kit

A used ECU kit for the C350 CDI allows for an economical repair of the engine control system while preserving the original Mercedes electronic architecture. This solution is particularly beneficial when the factory controller has been damaged, and repair is uneconomical or impossible. The main advantages of such a solution include:

• Restoring correct diesel engine control without the need for costly replacement of the entire powertrain,
• preserving the factory operating logic of the OM642.834 unit and the 265 HP power characteristic,
• the possibility of adapting to a specific car configuration thanks to compliance with OEM designations and interchangeable part numbers (details in the technical specification).

Compatibility, Selection, and Installation

To correctly select this ECU kit for a specific Mercedes model, it is crucial to verify compatibility by OEM number, reference numbers, and engine and gearbox configuration. For diesel engines with automatic transmissions, hardware and software compatibility is particularly important to maintain correct communication with other vehicle modules. During installation, it is recommended to:

• verify compatibility by part numbers and car equipment,
• entrust adaptation and potential programming to a specialized service center,
• adhere to safety procedures when working with the vehicle's electrical system. If you want to better understand how to safely choose and install used control modules, it is worth consulting the practical guide from Global Parts: Used Automotive Electronics Onboard – Why Choose Second-Hand ECU Modules and Sensors?.

Application in Diesel Powertrains

This ECU kit is designed to work with diesel engines, so its control map, injection strategies, and auxiliary equipment management are optimized for the characteristics of a diesel unit. In conjunction with an automatic transmission, it enables smooth torque management, which translates to driving comfort and proper gearbox operation. A correctly selected electronic engine control module helps maintain:

• proper acceleration dynamics,
• stable idle speed,
• consistent operation with the vehicle's onboard systems.

Expanding the Control System in a Mercedes

If you are planning a comprehensive repair or modernization of the engine area in your Mercedes and require other components from the same group, such as additional controllers, cooperating modules, or auxiliary controllers, check the available parts in the Mercedes Electronic Control Modules and Controllers category.

Summary

The ECU kit for Mercedes W204 C350 CDI OM642.834 265 HP with automatic transmission is a technically advanced, used control set that allows for the restoration of correct diesel engine operation and its integration with the automatic gearbox. By preserving the original Mercedes electronic architecture, it provides a practical solution for workshops and users seeking a proven control module from the aftermarket.