BMW F20 LCI 118i B38 136HP Engine ECU Kit DME 8486839 + FEM + Key Automatic

BMW F20 LCI 118i B38 136HP Engine ECU Kit DME + FEM + Key Automatic is a set of original electronics designed for professional repair or replacement of the factory control system. Combining the engine control unit, body module, and key in one set significantly facilitates adaptation in the vehicle and reduces the risk of immobilizer-related issues. This solution is particularly beneficial when replacing a damaged DME or performing an engine swap.

Specifications and technical data

• SKU: 8486839
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 8486839
• Substitutable numbers: 8486839, 12148486839, 8674265, 12148674265, 8648362, 12148648362, 8654454, 12148654454, 8781423
• Gearbox type: Automatic
• Category: ECUs & Computer Modules

Purpose and function of the ECU kit

BMW F20 LCI 118i B38 136HP Engine ECU Kit DME + FEM + Key Automatic is a set from the Electronic control modules and ECUs category, designed to work with the 136 HP B38 petrol engine in the facelift (LCI) version. The set is responsible for precise control of the engine's operation, communication with the body module, and ignition authorization via the matched key.

The presence of the FEM module in the set allows for maintaining vehicle data consistency, and the matched key minimizes the need for deep security system programming. As a result, this set is particularly useful in situations where the original controller has been damaged or there are issues with immobilizer synchronization.

Kit components and their roles

The set includes three key elements of the vehicle's electronic system:

• DME engine control unit – manages fuel injection, ignition, engine operating strategies, and cooperation with the automatic transmission,
• FEM module – the central body module responsible for, among other things, comfort functions and security system integration,
• key – factory-paired with the FEM module, essential for proper ignition authorization.

A set configured in this way allows for a consistent replacement of the entire engine control and security path, which in practice limits the number of potential failure points. The set is prepared for use with an automatic transmission, which is important when selecting the appropriate software and control maps.

Benefits of using a pre-owned DME + FEM + key kit

Choosing a pre-owned ECU kit for the BMW F20 LCI 118i B38 is a solution that combines economic aspects with the preservation of factory control logic. Original modules from a donor vehicle ensure compatibility with BMW's electrical architecture and predictable behavior of onboard systems.

The main advantages of this solution include:

• electronic consistency – the engine control unit, FEM module, and key come from a single system, which facilitates configuration,
• preservation of factory operating strategies for the 136 HP B38 engine,
• the ability to restore full vehicle functionality after a controller failure or immobilizer issues,
• cost reduction compared to purchasing new modules while maintaining original BMW quality.

With proper selection for a specific vehicle configuration and professional installation, the ECU kit with automatic transmission allows for an effective and technically correct repair of the drivetrain control system.

Professional installation and selection by OEM/VIN

Due to the complexity of the BMW F20 LCI electronic architecture, the installation of the DME + FEM + key set should be carried out by a workshop with experience in working with BMW electronics and appropriate diagnostic software. In practice, it is necessary to verify hardware and software compatibility with the specific vehicle equipment version, as well as to match the configuration to the existing installation.

To better understand the principles of selecting pre-owned controllers and modules, differences in software versions, and typical adaptation procedures, it is worth checking the guide on our blog: Used automotive electronics – ECU modules and second-hand sensors. The article discusses, among other things, selection by OEM or VIN number, HW/SW compatibility issues, and practical installation examples.

Related BMW control modules

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 additional controllers, body modules, or drivetrain management systems, check the available parts in the BMW Electronic control modules and ECUs category.