BMW E81 E87 LCI E90 N43 120i 320i 170HP ECU Kit DME 7621178 CAS3 Key Automatic

BMW E81 E87 LCI E90 N43 120i 320i 170HP ECU Kit DME CAS3 Key Automatic is a complete engine control and immobilizer kit designed for petrol-powered BMW 1 and 3 Series models with automatic transmissions. The set includes the DME engine control module, the CAS3 module, and a matched key, which facilitates restoring the electronic system's functionality after a failure or engine replacement. This solution allows for consistent, technically correct integration of the powertrain electronics with the vehicle's electrical system.

Specifications and technical data

• SKU: 7621178-7
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7621178
• Substitutable numbers: 12147640015, 7640015, 12147621178, 7621178, 5WK94901, 61359395657 61359262361, 9395657 9262361
• Fuel type: Petrol
• Gearbox type: Automatic
• Category: ECUs & Computer Modules

Application and compatibility

The presented ECU kit is intended for BMW vehicles with the 170 HP N43 petrol engine, used in models such as the 120i and 320i. The kit's design has been developed for compatibility with automatic transmissions, ensuring proper communication between the engine controller, the CAS3 module, and the transmission system. Thanks to this solution, it is possible to restore the original powertrain operating logic without the need for time-consuming adaptation of individual modules.

ECU kit construction and component functions

The DME engine control kit with CAS3 module and key consists of an electronic control module responsible for managing the engine's operation, the CAS3 comfort and security module, and a matched key. This set ensures the consistency of immobilizer data, which is crucial when replacing electronics in modern BMW vehicles. The kit has been designed for stable operation with the electrical installation and communication buses in E81, E87 LCI, and E90 models.

Combining these elements into one package reduces the risk of start authorization issues, communication errors between modules, and the need for complex programming. For workshops specializing in the BMW brand, this means faster diagnostics and more efficient execution of repairs related to engine electronics.

Benefits of using an original used kit

An original, used BMW ECU kit ensures the preservation of factory engine and automatic transmission control logic, which translates into predictable vehicle behavior and correct cooperation with other onboard modules. Compared to universal or incomplete solutions, such a set minimizes the risk of software incompatibility, coding problems, and improper immobilizer system operation.

Electronic control modules and controllers in modern BMWs are closely linked, which is why replacement in the form of a complete DME + CAS3 + key kit is often the most effective repair method after engine controller damage, electrical system flooding, or key authorization issues. This solution is particularly beneficial when repairing vehicles after collisions or during engine swaps.

Integration with BMW electronic systems and service knowledge

When installing the ECU kit in BMW 1 and 3 Series, it is essential to correctly perform adaptation procedures and verify communication with other modules, such as the multimedia system or body control modules. For specialists dealing with BMW electronics, valuable practical knowledge can be found in material describing work with used controllers and modules. Detailed tips on using dismantled parts in the 3 and 5 Series can be found in the article Driving pleasure for years – how to take care of iDrive systems and electronic modules in BMW 3 and 5 Series models using dismantled parts?, which discusses, among other things, issues related to FRM modules and engine controllers.

Expanding repairs within BMW electronics

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, comfort modules, or powertrain management systems, check the available parts in the BMW electronic control modules and controllers category.