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

BMW 3 5 Series E60 LCI E90 M57N2 325d 525d 197HP ECU Kit DME CAS3 Key is a complete electronic set from the Electronic control modules and controllers category, designed for M57N2 diesel engines with 197HP in BMW 3 Series E90 and 5 Series E60 LCI models. The set includes the DME engine control unit, the CAS3 module, and a matched key, which ensures seamless, factory-standard cooperation of all components within the starting system and engine management.

Specifications and technical data

• SKU: 7809941-1
• 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

Purpose and function of the ECU DME CAS3 Key kit

The presented set is dedicated to BMW vehicles with the 197HP M57N2 engine, where the engine control unit, CAS3 module, and key must be electronically synchronized. Using a complete set helps avoid issues with the immobilizer, communication errors between modules, and difficulties in adapting individual components.

In practice, this means that after proper installation and configuration, the vehicle regains stable engine management, correct key recognition, and consistent operation of the security system. This solution is particularly useful when replacing a damaged control unit or during repairs following collisions and electrical system failures.

Benefits of using an original BMW kit

Using original BMW components for engine management and the immobilizer provides a number of practical benefits:

• preservation of factory engine operation logic and onboard systems,
• software consistency between the DME control unit and the CAS3 module,
• minimized risk of conflicts with other modules in the vehicle,
• easier diagnostics using factory service tools,
• the ability to restore full vehicle functionality after an electronics failure.

For workshops specializing in the BMW brand, such a set provides a convenient base for professional repair, and for the end user, it means greater predictability of the powertrain and starting system performance.

Technical characteristics regarding installation

As an item from the Electronic control modules and controllers category, the set requires professional installation and proper configuration using BMW-compatible diagnostic tools. It is crucial to follow the correct sequence of work: installing the engine control unit, integrating the CAS3 module with the vehicle's wiring, and then configuring the key and checking bus communication.

During installation, it is worth paying attention to:

• the condition of electrical harnesses and connectors in the engine bay and inside the vehicle,
• correct mounting of the control unit in its original location,
• verification of error codes in the DME and CAS3 memory after the first start,
• testing the start/stop function and key response.

This approach helps reduce diagnostic time and allows for faster restoration of full vehicle functionality after replacing the electronics.

Product condition and service application

The offered set is used, which makes it an attractive cost-effective solution while maintaining original BMW specifications. This is particularly beneficial when repairing older E90 3 Series and E60 LCI 5 Series models, where full replacement with new components may not be economically justified.

In practice, such a set is suitable in situations where:

• the engine control unit or CAS3 module has been damaged,
• the vehicle has starting issues related to the immobilizer,
• a set replacement is necessary after water damage or an electrical short circuit,
• a workshop is performing a comprehensive electronics repair in the powertrain area.

BMW electronic control modules and controllers – expansion and selection

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

More about the role of original modules in modern cars

Modern premium cars, such as BMW or Audi, rely heavily on the cooperation of many controllers and comfort modules. Well-matched, original components allow for maintaining the vehicle's character, its throttle response, transmission operation, or multimedia systems. If you are interested in how used electronic components help maintain the factory properties of premium cars, it is worth reading the article Audi and emotions in their purest form. How do used parts help maintain the brand's DNA?, which shows the importance of original modules in daily operation.