BMW E90 E91 LCI E92 330d Diesel N57 245HP ECU Engine Kit DDE 8510221 CAS3 + Key

BMW E90 E91 LCI E92 330d Diesel N57 245HP ECU Engine Kit CAS3 + Key is a complete, used electronic package designed for the N57 245HP diesel powertrain. The kit includes the ECU engine controller, the CAS3 module, and a matched key, ensuring seamless, factory-spec compatibility between components. This solution is particularly useful when replacing a faulty controller or performing an engine swap in a BMW 3 Series E90 diesel model.

Specifications and technical data

• SKU: 8510221-15
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 8510221
• Substitutable numbers: 13618510221, 8510221, 13618506086, 8506086, 13618506377, 8506377, 13617823973, 7823973, 13617823513, 7823513, 13618506444, 8506444, 13618507136, 8507136, 0281016838, 0 281 016 838, 61359237047, 9237047, KZ
• Fuel type: Diesel
• ECU type: Engine Control Unit
• Category: ECUs & Computer Modules

Purpose and function of the ECU kit

The presented kit belongs to the Electronic control modules and controllers category and plays a key role in managing the operation of the diesel engine. The ECU is responsible for precise fuel dosing, boost pressure control, fuel injection system operation, and communication with other vehicle systems. Thanks to the synchronization with the CAS3 module and the key, the integrity of the security system and proper ignition authorization are maintained.

The completeness of the kit reduces the risk of issues with the immobilizer, CAN bus communication errors, or the need for time-consuming individual component matching. It is a practical solution for workshops specializing in BMW electronics and for users looking for a cohesive control package for the N57 engine.

Benefits of using a complete CAS3 + ECU + key kit

Using a ready-to-install control kit provides a number of technical and service benefits, especially for advanced diesel units:

• maintained compatibility between the engine controller, CAS3 module, and key,
• reduced need for deep immobilizer programming,
• easier diagnostics and configuration using factory BMW tools,
• consistent operation of the starting system and vehicle security,
• possibility of efficient replacement of a damaged ECU in a diesel engine without interfering with the entire installation.

For the N57 diesel engine, stable controller operation is particularly important, as it manages many combustion parameters and engine protection functions. The complete ECU kit with CAS3 and key allows for restoring proper powertrain operation while maintaining factory security logic.

Technical characteristics and integration with the diesel system

As an Engine Control Unit designed for a diesel engine, the controller is engineered to operate in the demanding thermal and electrical conditions typical of modern diesel units. It is responsible for interacting with pressure, temperature, and airflow sensors, as well as actuators such as injectors or control valves.

The CAS3 module included in the kit provides support for vehicle access and starting functions, while the matched key enables proper authorization. As a result, the entire package can be used as a base to restore the functionality of the electronic system in a BMW E90 with an N57 engine, while maintaining a high level of security.

Condition, verification, and service application

The kit is a used item, which in workshop practice often represents a reasonable compromise between repair cost and functionality. This type of solution is frequently chosen for:

• repairs following engine controller failure,
• replacing a complete diesel engine along with electronic accessories,
• resolving issues with the immobilizer and lack of ECU–CAS3 communication,
• engine swap projects within the BMW platform.

Before installation, a standard diagnostic procedure and verification of software compatibility with the specific vehicle configuration are recommended. Professional installation and adaptation at a specialized BMW or automotive electronics service will allow you to fully utilize the potential of the kit.

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

More about used automotive electronics

When choosing a used ECU kit with a CAS3 module and key, it is worth knowing the best practices regarding the selection, testing, and installation of such components. How to assess the condition of a controller, what to look for when purchasing, and how to minimize the risk of problems after installation is explained in the article: The second life of electronics – when is it worth choosing used engine controllers, comfort modules, and parking sensors?.