BMW E81 E87 LCI E90 120d 320d N47 177HP ECU KIT DDE 7811700 CAS3 Keys Automatic

BMW E81 E87 LCI E90 120d 320d N47 177HP ECU KIT DDE 7811700 CAS3 Keys Automatic is a complete, used set from the Electronic control modules and controllers group, designed for BMW vehicles equipped with an automatic transmission. The set includes an ECU engine controller along with a CAS module and key, which facilitates seamless integration with the factory security system and vehicle electronics.

Specifications and technical data

• SKU: 7811700-4
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7811700
• Substitutable numbers: 13618506199, 8506199, 13617811700, 7811700, 13618512587, 8512587, 02810150438, 0281015043, 61359147220, 9147220, 13617812500, 7812500, 13617812000, 7812000, 13617810000, 7810000, 13617809000, 7809000, 13617808401, 7808401, 13617807827, 7807827, 13617807530, 7807530, 13617807200, 7807200, 13617807142, 7807142, 13617806699, 7806699
• Gearbox type: Automatic
• Category: ECUs & Computer Modules

Purpose and function of the ECU + CAS kit

The presented control set is designed as an element of the engine management and start authorization system in BMW E81, E87 LCI, and E90 series models. Combining the ECU controller with the CAS module and a matched key allows for maintaining immobilizer data consistency, which significantly simplifies the installation process compared to replacing individual components. In vehicles with an automatic transmission, the engine controller works with the transmission electronics; therefore, using the appropriate set is crucial for the proper operation of the drivetrain, smoothness of gear changes, and stability of engine performance parameters.

Benefits of using a complete ECU controller kit with CAS key

Using a complete set brings a number of practical advantages in the process of repairing or upgrading vehicle electronics:

• data consistency between the ECU, CAS module, and key – reduces the risk of start-up and communication problems within the vehicle network,
• easier adaptation in the vehicle – the set is prepared to work as an integrated system,
• possibility to use it as a base for further configuration by a specialized service,
• preservation of the original BMW electronic architecture without the need for substitute solutions. For workshops specializing in the BMW brand, such a set is a convenient service solution, allowing to shorten diagnostic and installation time and reduce the number of potential failure points in the area of control electronics.

Integration with automatic transmission

In BMW vehicles with an automatic transmission, the engine controller works with modules responsible for gear shift logic, torque control, and drivetrain protection. Using the appropriate ECU set with a CAS module and key helps maintain:

• proper communication between the engine and the transmission control unit,
• stable gear shift strategies in various driving modes,
• consistency of security functions related to starting and selecting the transmission range. Thanks to this, the set can be used both for repairs after a controller failure and for replacing a damaged CAS module in vehicles with an automatic transmission.

Product characteristics and service application

The offered set comes from the line of original BMW solutions and is assigned to the Electronic control modules and controllers group. The used nature of the product makes it a cost-effective alternative to new components, while maintaining the original design and purpose. The set can be particularly useful in the following situations:

• vehicle repair after damage to the engine controller or CAS module,
• restoring the efficiency of the start-up and immobilizer system,
• servicing fleet vehicles where cost optimization is important while maintaining original solutions,
• renovation projects of E81, E87 LCI, and E90 models where it is necessary to replace control electronics components. Due to the specificity of BMW electronics, it is recommended to entrust the installation and configuration of the set to a workshop with experience in working with the brand's ECU and CAS systems.

Technical support and selecting the right controller

When choosing a used engine controller set, CAS module, and key, it is crucial to pay attention to compatibility with the specific vehicle version and equipment configuration. To better understand when choosing used electronics is justified and how to safely carry out such a replacement, it is worth reading the guide: Second life for electronics – when is it worth choosing used engine controllers, comfort modules, and parking sensors?. If you are planning a comprehensive repair or upgrade of the control electronics area in your BMW and need other components from the same group, such as engine controllers, comfort modules, or CAS systems, check the available parts in the BMW electronic control modules and controllers category.