BMW E90 E92 E93 M3 Engine S65 420HP ECU Control Unit Kit DME 7846409 + CAS3 Key

BMW E90 E92 E93 M3 Engine S65 420HP ECU Control Unit Kit DME + CAS3 Key is an original component from the Electronic control modules and controllers group, designed for advanced engine management in sports BMW 3 Series M3 models. This used controller ensures factory-standard operating logic, maintaining consistency with the vehicle's electrical architecture and the parameters specified by the manufacturer.

Specifications and technical data

• SKU: 7846409-1
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7846409
• Substitutable numbers: 12147848125, 7848125, 12147842487 12147841981 12147841364, 12147841365 12147846903 12147842404, 12147842403 12147840872 12147841102, 12147846409 12147846055 12147842905, 12147841982 12147845558 12147842488, 12147840873 12147842191 12147842192, 7842487 7841
• Category: ECUs & Computer Modules

Purpose and function of the module

The presented computer module is the central component responsible for controlling engine operation in the BMW E90, E92, and E93 in the M3 version. As a controller from the Electronic control modules and controllers family, it supervises, among other things, fuel injection, ignition, auxiliary equipment operation, and communication with other vehicle systems via data buses. This ensures proper dynamics, engine stability, and compliance with factory control maps.

The original origin of the module allows for maintaining proper compatibility with the electrical installation, wiring harnesses, and other controllers in the vehicle, which is crucial when replacing ECU components in modern BMW designs.

Benefits of using an original BMW module

Using an original computer module in a BMW M3 E9x series offers a number of practical advantages:

• preservation of factory engine performance characteristics and cooperating systems,
• consistency with the software and configuration intended for the given M3 generation,
• proper communication with other controllers in the vehicle,
• possibility of diagnostics using standard BMW service tools.

As a result, the module represents a sensible solution for repairs where it is necessary to restore the correct operation of the engine control system without interfering with the vehicle's construction.

Condition, origin, and installation aspects

The module is offered as a used component, which allows for an economical approach to repair while maintaining the original manufacturer's specifications. Such controllers are particularly valued in sports vehicles, where matching the specific model version and maintaining factory operating parameters is essential.

Before installation, it is recommended to verify compatibility by OEM number and interchangeable numbers, as well as to consult with an experienced electrician or diagnostician specializing in the BMW brand. In many cases, software matching (coding, adaptation to the vehicle) may be necessary, so it is worth considering this aspect at the repair planning stage.

Selection by numbers and compatibility – technical support

In the case of electronic engine controllers, correct selection by OEM part number and reference numbers is of key importance. This allows you to avoid problems with communication in the vehicle network, diagnostic errors, or incorrect engine operation. If you want to better understand how to safely choose used ECU controllers, how to interpret markings, and what to pay attention to during installation, use the advice contained in the article Used automotive electronics – a guide to selecting ECU modules and sensors.

Expanding the control system in BMW

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