BMW 3 Series E90 E92 E93 M3 S65 420HP ECU Kit DME + CAS3 + Key 7842487 Manual

BMW 3 Series E90 E92 E93 M3 S65 420HP ECU Kit DME + CAS3 + Key Manual is a complete control kit designed for the sports versions of the BMW M3 with the 420 HP S65 engine and a manual transmission. The kit includes the DME engine control module, the CAS3 module, and a key, allowing for seamless management of the immobilizer and drivetrain electronics. This solution is particularly useful when replacing a damaged ECU, performing a drivetrain swap, or rebuilding a vehicle after a collision.

Specifications and technical data

• SKU: 7842487-1
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7842487
• Substitutable numbers: 12147848125, 7848125, 5WK95903, 61359147226, 9147226, 12147842487 12147841981 12147841364, 12147841365 12147846903 12147842404, 12147842403 12147840872 12147841102, 12147846409 12147846055 12147842905, 12147841982 12147845558 12147842488, 12147840873 1214784
• Gearbox type: Manual
• Category: ECUs & Computer Modules

Purpose of the ECU kit for BMW M3 S65

The kit has been designed for the BMW 3 Series E90, E92, and E93 generations in the M3 version with the naturally aspirated 420 HP V8 S65 engine. Combining the DME controller with the CAS3 module and a matched key ensures system security consistency and proper communication with the vehicle's wiring. As a result, this kit is ideal for replacing a factory ECU, performing body conversions within the same generation, and for track or road vehicle restoration projects.

Functionality of the DME and CAS3 modules

The DME module is responsible for the precise control of the S65 engine's operation – fuel injection, ignition, and interaction with other vehicle systems. The included CAS3 module manages start authorization, communication with the key, and interaction with the vehicle's security systems. The presence of a matched key simplifies the installation and configuration process, as all components come from a single set and are synchronized regarding the immobilizer.

Compatibility with manual transmission

The kit is prepared for use with a manual transmission, which is crucial when selecting a controller for a specific drivetrain configuration. The appropriate maps and DME operating logic are adapted to the characteristics of a manual gearbox, facilitating the proper functioning of features related to torque control, throttle response, and interaction with other vehicle systems. This is especially important when replacing an ECU in cars driven dynamically, where drivetrain configuration consistency has a direct impact on vehicle handling.

Benefits of using a pre-owned ECU kit

Choosing a pre-owned ECU DME + CAS3 + key kit allows for significant cost savings on repairs or upgrades compared to purchasing new components, while maintaining the original BMW electronic architecture. A complete kit minimizes the risk of immobilizer matching issues, which often occur when replacing individual modules. It is a practical solution for workshops specializing in the BMW brand and for users building track projects based on the M3 E90/E92/E93.

Electronic control modules and technical support

If you are planning a comprehensive repair or upgrade of your BMW's engine electronics and need other components from the same group, such as additional controllers, security modules, or systems interacting with the powertrain, check out the available parts in the BMW electronic control modules and controllers category.

When selecting a pre-owned ECU, CAS modules, and other electronic components, it is worth paying attention to hardware and software part number compatibility as well as installation methods. A detailed discussion on selection principles based on OEM numbers, compatibility issues, and practical examples can be found in the Global Parts guide: Used automotive electronics on board – why choose pre-owned ECU modules and sensors?.

Summary

BMW 3 Series E90 E92 E93 M3 S65 420HP ECU Kit DME + CAS3 + Key Manual is a coherent, original control kit intended for the M3 version with the S65 engine and manual transmission. Combining the DME, CAS3, and key into one set facilitates installation, reduces immobilizer-related issues, and allows for maintaining the factory logic of the drivetrain. It is a sensible choice for professional workshops and conscious users looking for a technically matched solution for repairing or rebuilding engine electronics in their BMW M3.