BMW 3 5 Series E60 LCI E90 325d 525d M57N2 197HP ECU Kit DDE 7809941 CAS3 + Key

BMW 3 5 Series E60 LCI E90 325d 525d M57N2 197HP ECU Kit DDE CAS3 + Key is a complete engine control kit for BMW 3 Series E90 and 5 Series E60 LCI models equipped with the 197 HP M57N2 engine. The set includes the DDE controller, CAS3 module, and a matched key, ensuring seamless, factory-standard integration between the powertrain electronics and the immobilizer system. This is a practical solution for workshops and users performing replacements or repairs of the engine control system in BMW vehicles.

Specifications and technical data

• SKU: 7809941-4
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7809941
• Substitutable numbers: 13617809941, 7809941, 0281015130, 0 281 015 130, 13618509034, 8509034, 13617811151 13617806380 13617806987 13617806152, 7811151 7806380 7806987 7806152, 13618506951 13617805288 13617808314 13617804845, 8506951 7805288 7808314 7804845, 0281014436 0 281 014 436, 61356
• Category: ECUs & Computer Modules

Application of the ECU DDE CAS3 + Key kit

The presented kit is designed for BMW 3 Series E90 325d and BMW 5 Series E60 LCI 525d vehicles with the 197 HP M57N2 diesel engine. Combining the DDE controller with the CAS3 module and the key ensures security data consistency, which facilitates vehicle adaptation and reduces the need for extensive software intervention. This type of set is particularly useful when replacing a damaged engine controller or during post-collision repairs, where restoring communication between the powertrain electronics and the vehicle start system is required.

Design and function of the kit components

The kit includes an electronic DDE engine controller responsible for precise management of the M57N2 unit, including fuel injection, boost control, and communication with other vehicle modules. The CAS3 module acts as the central element of the access and start system, communicating with both the key and the engine controller. The included key is synchronized with the CAS3, which maintains the integrity of the immobilizer system and facilitates the restoration of full vehicle functionality after installation.

Benefits of using a complete kit

Using a complete ECU DDE kit with CAS3 and a key reduces diagnostic and programming time compared to replacing individual modules. Component consistency minimizes the risk of CAN bus communication conflicts and start authorization issues. For workshops specializing in BMW, this means faster service execution, and for the end user – greater repair predictability and stable operation of the powertrain.

Condition, origin, and technical aspects

The elements included in the kit are sourced from dismantling and are offered as used electronic control modules and controllers. These types of components are frequently used in professional BMW service centers because they allow for economical repair while maintaining the vehicle's original electronic architecture. Before installation, it is recommended to perform a full vehicle diagnostic, verify the compatibility of equipment versions, and carry out the necessary adaptation procedures in the software, in accordance with BMW service practices.

Technical support and service knowledge

If you want to better understand how to properly service a BMW engine controller, comfort modules, and the iDrive system in the 3 and 5 Series, it is worth using the practical tips included in the article Driving pleasure for years – how to take care of iDrive systems and electronic modules in BMW 3 and 5 Series models. There, you will find information regarding working with dismantled parts, which helps optimize the repair process and reduce operating costs.

If you are planning a comprehensive repair or upgrade of the engine electronics area in your BMW and need other elements from the same group, such as engine controllers, comfort modules, or transmission control units, check the available parts in the BMW electronic control modules and controllers category.