BMW E87 E90 CAS2 ECU Control Unit Module 61356943791 6943791

The BMW E87 E90 CAS2 M Comfort Module Controller is an original part from the Electronic Control Modules and Controllers category, designed for advanced management of comfort functions in BMW E87 and E90 series vehicles. The CAS2 M module is responsible for start authorization, key handling, and communication with other electronic systems, ensuring consistent and stable operation of the electrical system.

Specifications and technical data

• SKU: 6943791
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 6943791
• Substitutable numbers: 61356943771, 6943771, 61356943791 61356981416 61356943786, 61356943775 61356943766 61356964051, 6943791 6981416 6943786 6943775 6943766 6964051
• Category: ECUs & Computer Modules

Purpose and Function of the CAS2 M Module

The CAS2 M Comfort Module Controller acts as the central element of the access and start system in BMW E87/E90, integrating comfort functions with the vehicle's security system. It is responsible for, among other things:

• handling the electronic key and authorizing engine start,
• interacting with the vehicle's electrical system for comfort functions,
• communicating with other controllers in the vehicle network.

As a result, the module is a key component of the electronic architecture, influencing user convenience and vehicle operational safety.

Compatibility and Interchangeable Numbers

The presented controller belongs to the group of BMW Electronic Control Modules and Controllers, for which the manufacturer has provided various part numbers and interchangeable numbers. This means that within the same CAS2 M family, there are references that can be used interchangeably, provided there is hardware and software compatibility with the specific vehicle configuration.

Before purchasing, it is recommended to verify compatibility using the OEM part number and compare the available interchangeable numbers with the currently installed module. This helps to reduce the risk of communication problems within the vehicle network and ensures proper interaction with other controllers.

If you need a wider selection in this group, check out other BMW Electronic Control Modules and Controllers to select a part optimally suited to your car's configuration.

Benefits of Using an Original BMW Module

Using an original CAS2 M module in BMW E87/E90 offers a number of practical benefits:

• Factory Integration with the System – the controller is designed for a specific platform, which facilitates installation and reduces the need for wiring modifications.
• Consistent Communication within the Vehicle Network – proper interaction with other controllers minimizes the risk of errors and fault messages.
• Possibility of adaptation and coding according to the car's equipment, which allows for maintaining comfort functions at the factory level.
• Better predictability of operation compared to universal replacements.

For workshops and users, this means stable operation of the comfort system and a reduced risk of service returns related to incorrect controller communication.

Condition, Verification, and Selection by OEM

The offered module comes from the group of used BMW OE parts, which allows for a significant reduction in repair costs while maintaining the original manufacturer's specifications. Before installation, a standard diagnostic procedure is recommended, and if necessary, software adaptation to the specific vehicle (coding, synchronization with immobilizer and key).

To correctly select the controller, it is advisable to use the OEM part number and the list of interchangeable numbers, as well as the vehicle's VIN. A detailed discussion of selection principles, hardware and software compatibility, and practical examples can be found in the guide: Used Automotive Electronics Onboard – Why Choose Second-Hand ECU Modules and Sensors?

Why Choose a Used BMW Comfort Module

Choosing a used CAS2 M module is a sensible solution for drivers and service centers who want to control costs while maintaining original BMW quality. You receive a part designed specifically for the given platform, with its hardware architecture preserved and the possibility of full integration with the vehicle's electronics. It is a practical alternative to new controllers, especially for maintenance repairs or restoring a vehicle's functionality after electrical system failures.