BMW 1 3 5 Series E60 E87 E90 CAS 3 ECU Control Unit Key Reading Module 6943814

BMW 1 3 5 Series E60 E87 E90 CAS 3 ECU Control Unit Key Reading Module is a factory-original module from the Electronic control units and controllers category, responsible for managing the access and key recognition system in selected BMW 1, 3, and 5 Series models. This CAS 3 controller works with the vehicle's electrical system, ensuring proper ignition authorization and communication with other comfort and safety modules.

Specifications and technical data

• SKU: 6943814
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 6943814
• Substitutable numbers: 61359226238, 9226238, 61359395657, 9395657, 61359287535613592370476135921785361359147226, 9287535923704792178539147226, 61356943814, 6943814, 61356943797, 6943797, 61359217853, 9217853, 61359147226, 9147226, 61359147221, 9147221, 61359147191, 9147191, 61359147195, 9147195, 61359147184, 9147184, 61356943834, 6943834, 61356943822, 6943822, 61356943771, 6943771, 61356943791, 6943791, 61356981416, 6981416, 61356964051, 6964051, 61356943766, 6943766, 61356943811, 6943811, 61356943796, 6943796
• Category: ECUs & Computer Modules

Purpose and function of the CAS 3 module

The presented CAS 3 controller plays a key role in the BMW electronic vehicle access system, responsible for key reading, engine start authorization, and data exchange with other controllers on the CAN bus. The module works with the factory immobilizer, ignition switch, and keys, which directly impacts vehicle security and daily operational stability. Thanks to the use of an original BMW solution, the module maintains full compatibility with the electrical architecture of the given generation of 1, 3, and 5 Series models, which facilitates integration with the existing installation and reduces the risk of communication errors between controllers.

Benefits of using an original BMW module

Using an original CAS 3 module from the Electronic control units and controllers category allows you to maintain the consistency of the vehicle's software and configuration. In practice, this means:

• preserving factory functions related to ignition and immobilizer,
• proper cooperation with other comfort and safety controllers,
• reduced risk of coding and adaptation issues compared to low-quality replacements,
• easier diagnostics using dedicated BMW service tools. For workshops specializing in the BMW brand and users who care about maintaining the original vehicle configuration, choosing such a module is a practical and technically sound solution.

Product characteristics and the aspect of a used controller

The offered module is an original BMW part sourced from dismantling, which in many cases represents a beneficial compromise between repair costs and maintaining factory quality. A used CAS 3 controller can be particularly attractive in cases of electronic damage resulting from power surges, water ingress, or installation errors, where purchasing a new component is significantly more expensive. Before installation, this type of module usually requires appropriate programming or matching to a specific vehicle (coding, synchronization with the key and other controllers), which is best entrusted to a specialized service. Properly performed adaptation allows for restoring full functionality of the access and ignition system without the need for deep interference with the installation.

Application in service and tuning practice

The CAS 3 module is often used not only for standard repairs but also for more advanced tasks, such as wiring harness replacement, equipment reconfiguration, or vehicle reconstruction after a collision. For automotive electronics technicians and diagnosticians, it is an important element of the system whose proper operation affects the ability to start the car, the operation of the central locking, and integration with comfort systems. In combination with appropriate diagnostic tools, communication tests, software updates, and synchronization procedures can be performed, allowing for precise matching of the module to the specific configuration of a BMW 1, 3, or 5 Series.

More knowledge about BMW electronic modules

If you want to better understand how controllers work in your BMW and how to safely use parts from dismantling when repairing comfort and multimedia systems, check out the article: Driving pleasure for years – how to take care of iDrive systems and electronic modules in BMW 3 and 5 Series models. You will find practical tips there regarding work with modules such as CAS, FRM, or engine controllers.

A sensible choice of used controllers

When planning the repair of electronic systems, it is worth considering when it pays off to reach for parts from dismantling and when it is better to opt for new components. The following guide may be helpful: Car parts – new or used? We compare costs, quality, and durability, which discusses the differences in durability, availability, and cost-effectiveness of individual solutions. If you are planning a comprehensive repair or upgrade of the control electronics area in your BMW and need other elements from the same group, such as comfort controllers, body modules, or ECU units, check out the available parts in the BMW electronic control units and controllers category.