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

The BMW E90 E91 LCI E92 330d N57 245HP Engine Computer ECU 8510221 CAS3 is an original engine control unit designed for BMW 3 Series diesel engines with the N57 engine producing 245 HP. This component from the Electronic Control Modules and Controllers group is responsible for precise engine management, ensuring stable power delivery and proper integration with other vehicle systems. This used control unit is an excellent choice for professional repair or replacement of a damaged ECU in diesel-powered vehicles.

Specifications and technical data

• SKU: 8510221-2
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 8510221
• Substitutable numbers: 13618510221, 8510221, 13618506086, 13618506377, 13617823973, 13617823513, 13618506444, 13618507136, 8506086, 8506377, 7823973, 7823513 8506444 8507136, 0281016838, 0 281 016 838, 61359262361, 9262361
• Fuel type: Diesel
• Category: ECUs & Computer Modules

Intended Use and Function of the Engine Controller

The presented engine computer is designed to work with the N57 diesel engine in BMW 3 Series models of the E90, E91 LCI, and E92 generations, specifically the 330d version. As the central control module for the powertrain, the ECU analyzes sensor signals, controls fuel injection, ignition timing, boost pressure, and auxiliary equipment parameters, which translates into smooth engine operation and predictable throttle response.

The version integrated with the CAS3 system works with the immobilizer, which is important for matching the controller to a specific vehicle. This ensures seamless communication between the engine electronics and the vehicle's security system.

Benefits of Using an Original BMW Module

Using an original BMW engine control unit allows you to maintain the factory engine management logic without the compromises often associated with aftermarket replacements. This is particularly crucial in modern diesel engines, where precise control of injection, boost, and auxiliary systems directly impacts performance, fuel economy, and stable operation under all load conditions.

For workshops and private users, this means:

• easier diagnostics based on standard BMW service procedures,
• software compatibility with other modules in the vehicle,
• the possibility of professional adaptation and coding using dedicated diagnostic tools.

For diesel engines, proper cooperation between the ECU and the injection system and emission control systems is particularly important – an original module significantly facilitates maintaining these parameters within the manufacturer's specified limits.

Application in the N57 Diesel Engine

The N57 engine in the 330d version is an advanced diesel unit where the controller plays a key role in managing common rail pressure, turbocharger operation, and engine protection strategies. A correctly selected engine computer enables:

• maintaining stable power and torque across the entire RPM range,
• proper operation of emission control systems,
• ensuring driving comfort through smooth response to load.

For users planning to repair or replace a damaged ECU in a 330d, choosing a controller dedicated to the N57 diesel engine is fundamental for trouble-free operation after installation and coding.

Condition, Origin, and Installation Aspects

The offered engine computer is a used part, sourced from disassembly, allowing for economical repair while maintaining original BMW specifications. Before installation, a full vehicle diagnostic is recommended, along with preparation for controller adaptation in the vehicle (coding, potential matching to CAS3 according to service procedures).

In workshop practice, such a module is used for both typical ECU failures and more complex engine electronics repairs where replacing the entire controller is necessary instead of localized mainboard repair.

Technical Support and Additional Information

If you want to better understand how to properly approach the repair of BMW engine controllers, comfort modules, or the iDrive system in the 3 and 5 Series, it's worth reading the guide on our blog: Years of Driving Pleasure – How to Care for iDrive Systems and Electronic Modules in BMW 3 and 5 Series Models. You will find practical tips there on using proven used parts, including engine controllers.

If you are planning a comprehensive repair or upgrade of the engine area in your BMW and need other parts from the same group, such as glow plug controllers, boost control modules, or additional control units, check the available parts in the BMW Electronic Control Modules and Controllers category.