BMW F44 M235iX B48E 306HP Engine Unit ECU KIT DME 5A57781 BDC Key Automatic

The Complete ECU KIT for BMW F44 M235i xDrive with 306 HP B48E Engine is an advanced, factory original module from the Electronic Control Units and Controllers group, designed for vehicles with an automatic transmission and a gasoline engine. The kit includes the DME engine controller, BDC module, and key, facilitating consistent powertrain electronics matching and comfortable vehicle startup after replacement.

Specifications and technical data

• SKU: 5A57781-2
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 5A57781
• Substitutable numbers: 5A57781, 12145A57781, 0261S1066N, 0 261 S10 66N, 5A57242
• Fuel type: Petrol
• Gearbox type: Automatic
• Category: ECUs & Computer Modules

Purpose and Function of the ECU KIT

The presented ECU KIT for BMW F44 M235i xDrive B48E 306 HP is designed as the central element for managing gasoline engine operation in conjunction with an automatic transmission. The DME controller is responsible for precise control of injection, ignition, and cooperation with other vehicle systems, while the BDC module integrates comfort functions, keyless entry, and key communication.

This combination of components in a single kit allows for consistent transfer of powertrain electronics configuration between vehicles, minimizing the risk of authorization, immobilizer, or vehicle network communication issues.

Benefits of Using an Original BMW Control Module

An original module from the Electronic Control Units and Controllers group ensures high compatibility with the factory electrical architecture of the BMW F44 M235i xDrive. Thanks to this:

• correct cooperation with the 306 HP B48E gasoline engine is maintained,
• compatibility with the automatic transmission and driver assistance systems is preserved,
• the controller communicates with other modules in the vehicle according to the manufacturer's factory standards.

Choosing a used, original ECU KIT allows for a technically correct repair or replacement of the powertrain electronics while maintaining the factory operating parameters of the power unit.

Application in the 306 HP B48E Gasoline Engine and Automatic Transmission

The 306 HP B48E gasoline engine in the BMW F44 M235i xDrive requires precise control of operating parameters, especially when paired with an automatic transmission. The ECU KIT has been configured specifically for this drive specification, which translates to:

• correct engine mapping across the full range of loads,
• smooth cooperation with the automatic gearbox,
• preservation of factory performance characteristics and throttle response.

This makes the solution particularly useful for replacing a damaged controller or for comprehensive powertrain system repairs in this specific BMW model.

Condition, Verification, and Selection by Part Numbers

The component is from the aftermarket, allowing for economical repair while maintaining the original manufacturer's specifications. Before installation, it is recommended to verify compatibility by OEM number and interchangeable part numbers, as well as to match it based on engine version, fuel type, and transmission type.

To better understand how to safely select used control modules, what to look for when comparing hardware and software designations, and what the installation process looks like in practice, it is worth reading the guide: Used Automotive Electronics – Second-Hand ECU Modules and Sensors in Practice.

Expanding BMW Electronics Modernization

If you are planning a comprehensive repair or modernization of the engine area in your BMW and need other components from the same group, such as controllers, body modules, or comfort units, check the available parts in the BMW Electronic Control Units and Controllers category.

This approach allows for a consistent renewal of the entire electronic architecture responsible for the powertrain and onboard functions, which is particularly important in modern vehicles where most vehicle functions are tightly integrated at the controller network level.