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 an advanced electronic control module responsible for managing the access and key recognition system in selected BMW 1, 3, and 5 Series models. This component from the Electronic control modules and controllers category works with the vehicle's electrical system, ensuring proper communication between the key, the ignition switch, and other control units. The used CAS 3 module is a practical service solution for repairs of the electronic system related to vehicle starting.

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

Function and application of the CAS 3 module

The CAS 3 module plays a key role in the BMW electrical architecture, being responsible for key reading, start authorization, and communication with other ECU controllers. In practice, this means that a correctly selected and programmed module is essential for:

• proper key recognition in the vehicle,
• initiating the engine start sequence,
• cooperation with vehicle security systems,
• coordination of signals with other electronic modules.

As a result, the CAS 3 module is a vital component when diagnosing starting problems, immobilizer errors, or data bus communication interference.

Selection by OEM number and interchangeable numbers

Precise matching of the CAS 3 module to a specific BMW vehicle is performed based on the OEM part number and associated interchangeable numbers. This allows for selecting a controller compatible with the equipment version, model year, and vehicle electronics configuration. In practice, before purchasing, it is worth verifying compatibility by part number or VIN to avoid issues with programming and integration into the existing installation.

The presence of multiple reference numbers in the specification demonstrates the wide compatibility of the module within the CAS 3 family, which facilitates finding the right component for service repairs and electronic system upgrades.

Product characteristics and condition

The offered CAS 3 module comes from dismantling and is marked as a used original BMW part. This type of part is particularly attractive in situations where it is necessary to replace the controller while maintaining a favorable cost-to-functionality ratio. Modules from this group are designed for long-term operation in demanding temperature and electrical conditions, therefore a used unit, after proper coding, can still provide stable operation of the access and starting system.

Due to the nature of vehicle electronics, it is recommended to entrust the installation and adaptation of the CAS 3 module to a workshop experienced in programming BMW controllers, which minimizes the risk of communication errors and immobilizer problems.

Benefits of using an original BMW module

Choosing an original CAS 3 module from the Electronic control modules and controllers group brings a number of practical benefits:

• preservation of the factory logic of the access and starting system,
• reliable fitment to the electrical installation and CAN network architecture in BMW 1, 3, and 5 Series,
• easier coding and adaptation compared to universal solutions,
• the possibility of using parts from dismantling as an economical alternative to a new controller.

For workshops specializing in the BMW brand, such a module is a valuable service component, allowing for the effective resolution of vehicle starting and key communication issues.

Related modules and service knowledge

When working on the BMW electronic system – especially in 3 and 5 Series models – the CAS 3 module often works with other controllers, such as the engine control unit or comfort modules. It is worth familiarizing yourself with practical tips regarding work with the electronics of this brand, programming, and selecting parts from dismantling. An extended discussion of the topic can be found in the article Driving pleasure for years – how to take care of iDrive systems and electronic modules in BMW 3 and 5 Series models using parts from dismantling?, which describes, among other things, the approach to repairing control modules.

If you want to better understand the differences between new parts, replacements, and used items, and consciously choose a service strategy for your car, the guide Original, replacement, or used – which car parts are the most cost-effective?, discussing cost and quality aspects based on workshop practice examples, will also be helpful.

Other BMW electronic control modules

If you are planning a comprehensive repair or upgrade of the onboard electronics in your BMW and need other components from the same group, such as comfort controllers, light modules, or engine controllers, check the available parts in the BMW electronic control modules and controllers category.