Mercedes W218 CLS350CDI BlueTec OM642.852 Diesel 252HP ECU A6429007301 Automatic

Mercedes W218 CLS350CDI BlueTec OM642.852 Diesel 252HP ECU is a factory engine control unit designed for versions with an automatic transmission. This used module from the Electronic control modules and controllers category allows for professional powertrain repair without the need for expensive replacements, while maintaining the original performance characteristics of the diesel unit.

Specifications and technical data

• SKU: A6429007301-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6429007301
• Substitutable numbers: A6429007301, A 642 900 73 01, A6429012300, A 642 901 23 00, KZ
• Fuel type: Diesel
• Gearbox type: Automatic
• Category: ECUs & Computer Modules

Purpose and function of the controller

The presented ECU is dedicated to the Mercedes W218 CLS350CDI BlueTec model with an OM642.852 diesel engine producing 252 HP, paired with an automatic transmission. The module is responsible for precise management of the powertrain – fuel injection, boost control, combustion parameter monitoring, and communication with other vehicle systems.

By using an original ECU, software consistency with the car's electrical architecture is maintained, which facilitates adaptation in the vehicle and reduces the risk of compatibility issues. This solution is particularly beneficial for professional powertrain repairs in workshops specializing in the Mercedes brand.

Benefits of using an original ECU

Choosing a factory engine controller for the Mercedes CLS350CDI BlueTec provides a number of practical advantages:

• preservation of factory injection maps and engine control strategies,
• proper cooperation with the automatic transmission and comfort systems,
• consistency with the electrical installation and the vehicle's CAN network,
• possibility of further diagnostics and programming using standard service tools,
• reduction of the risk of communication errors between modules.

For workshops and users who value the predictability of powertrain operation, a used, original controller from this series is a technically sound choice, allowing for the restoration of full vehicle functionality at controlled costs.

Application in vehicles with diesel engines and automatic transmissions

The ECU has been designed to work with a diesel engine and an automatic transmission, which is crucial for smooth gear shifting and the refinement of the powertrain. Proper tuning of the controller to the engine's torque characteristics and transmission logic translates into:

• stable idle speed,
• smooth acceleration without jerking,
• proper operation of driving modes,
• efficient use of the diesel engine's potential.

A module configured in this way is particularly important in CLS-class cars, where a comfortable yet dynamic driving experience is expected.

Professional use in the workshop

This controller from the Electronic control modules and controllers category will prove useful both in independent workshops and in specialized services dealing with automotive electronics. It can be used for:

• repairs after damage to the original ECU,
• solving communication problems in the controller network,
• restoring powertrain configuration after a collision or water damage,
• advanced diagnostics of faults related to engine operation.

Combined with appropriate programming and adaptation procedures, it allows for the efficient restoration of full engine control system functionality in the Mercedes CLS350CDI BlueTec.

If you are planning a comprehensive repair or upgrade of the engine control area in your Mercedes and need other components from the same group, such as ECU modules, transmission controllers, or auxiliary system controllers, check out the available parts in the Mercedes electronic control modules and controllers category.

Knowledge and best practices when working with electronic modules

When selecting and installing engine controllers and other electronic modules, it is worth using proven service procedures and the experience of specialists. Practical tips on working with electronics in premium cars can be found in the article Driving pleasure for years – how to take care of iDrive systems and electronic modules in BMW 3 and 5 series models using dismantled parts?, which discusses universal principles for handling used modules, also useful in the context of the Mercedes brand.

If you want to better understand why used original components for premium cars are currently so valued, it is also worth reading the material Crisis in the new parts market? Why in 2026 used originals for premium cars (BMW, Mercedes, Porsche) are the hottest trend, which shows the broader market context and helps to consciously plan repairs for high-end vehicles.