Mercedes W221 S320 CDI OM642.930 Engine Control Unit ECU Kit A6421502500 Key

Visual condition of the part

The product shows signs of use visible in the photos.

Mercedes W221 S320 CDI OM642.930 Engine Control Unit ECU Kit is a complete engine control set designed for the OM642.930 diesel unit in the W221 generation S-Class. The kit includes the electronic engine control module along with related components, facilitating a seamless replacement of the control system and restoring proper powertrain operation in Mercedes vehicles. This solution is particularly useful for addressing starting issues, CAN network communication problems, or engine control unit errors.

Specifications and technical data

• SKU: A6421502500-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6421502500
• Substitutable numbers: A6421502500, A 642 150 25 00, 0281015342, 0 281 015 342, A2215451308, A 221 545 13
• Category: ECUs & Computer Modules

Purpose and function of the ECU kit

The presented kit belongs to the Electronic control modules and controllers category and is responsible for the comprehensive management of the diesel engine in the S320 CDI model. The ECU oversees, among other things, fuel dosing, boost pressure, auxiliary system operation, and communication with other vehicle modules, which directly impacts engine performance, efficiency, and fuel consumption.

The inclusion of a matched key in the kit facilitates integration with the immobilizer and the vehicle's security system, which is essential when replacing the complete engine control system. This allows for the efficient restoration of vehicle functionality following a failure of the original controller or issues with electronic synchronization.

Benefits of using an original Mercedes module

Using an original control module dedicated to the Mercedes S-Class W221 with the OM642.930 engine ensures:

• consistency with the factory electrical architecture and the vehicle's CAN network,
• proper cooperation with other comfort and safety modules,
• stable engine operating parameters under various load conditions,
• the ability to perform further diagnostics using professional service testers.

For workshops and users, this means easier configuration, predictable powertrain behavior, and a reduced risk of problems resulting from mismatched aftermarket replacements. The complete ECU kit with key is particularly beneficial for major engine electronics repairs when multiple components require simultaneous replacement.

Characteristics of the used ECU kit

The product comes from dismantling and is offered as a used control module, which significantly lowers repair costs compared to purchasing a new controller. At the same time, the original manufacturer's specification is maintained, which helps preserve factory engine performance parameters and compatibility with service software.

Before installation, it is recommended to perform a full vehicle diagnostic and verify configuration compatibility with the specific vehicle equipment version. In many cases, adaptation or programming at a specialized service center will be necessary for the ECU kit to be correctly integrated with the rest of the vehicle's electronics.

Practical service application and additional materials

The ECU kit for the Mercedes W221 S320 CDI OM642.930 is particularly useful in situations where the existing controller has been damaged, communication issues exist within the vehicle network, or a complete control system replacement is required due to failed programming attempts. This type of solution is favored by both independent workshops and services specializing in automotive electronics.

For a better understanding of how modern engine control systems and electronic modules work, it is worth checking out the guide material describing the repair of controllers and comfort modules in other premium brands – you can find practical tips in the article on servicing iDrive systems and electronic modules in BMW using salvaged parts. Although it concerns a different brand, it well illustrates the approach to diagnostics and installation of used modules.

Expanding repairs within Mercedes electronics

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

This approach allows you to organize key powertrain electronics in a single service stage, reduce vehicle downtime, and optimize repair costs while maintaining high-quality components.