BMW CAS Car Access System – Cloning Service / Data Transfer


MotorTronics provides a complete cloning / programming solution for your electronic modules, The modules goes through various data cloning processes to ensure all data is extracted / matched or modified to be plug and play, only after this, we pass it and it’s ready for dispatch.

All that is left for you to do is

1. Click Buy it Now / Add to Cart
2. Fill in the Order Form / Packaging Slip provided after the payment page.
3. Send your original CAS (Marked Original) and Replacement CAS (marked Replacement) with the Order Form
4. Await programming while we have your part(s)
5. Once received simply Plug it in and turn the key.
6. In some cases you will require diagnostics to adapt / clear codes.


BMW CAS Immobiliser

The CAS immobiliser module (transponder box) serves as an antitheft alarm system and enables the start of BMW vehicles. Within each vehicle key there is an integrated transponder chip, and a coil ring which is fitted around the ignition lock. The transponder chip is powered by this coil from the CAS module, meaning that no battery is necessary within the key. When your key is inserted in to the ignition, the transponder in the key is powered via the loop antenna, and key data is sent to the CAS control module. If the key data is correct, an enable signal is then sent to the starter and the CAS module then sends the random code to the Engine Control Module (DME / DDE) where the random code is checked against the saved random code. Only if they match, is the fuel injection released allowing the car to start.

The BMW CAS (car access system) manufactured by Siemens VDO, commonly suffers from internal hardware and software failures resulting in intermittent to complete none start

Common faults associated with the BMW CAS Immobiliser module
some of the issues that you may encounter if you have a problem with your BMW CAS module are:

  • Immobiliser Fault Codes
  • No Communication with CAS Module
  • Vehicle Won’t Start
  • Key Not Recognised
  • Failed CAS after key programming
  • Corrupted software due to failed programming
  • No terminal 50 output circuit (Starter Relay)

Most workshops will advise to replace the immobiliser module because they are unable to repair it.

This is a Cloning Service, therefor if you Believe your unit is faulty all you need to do is send us your Original unit and a Replacement of the same HW type or same part number.


This service covers the programming of the replacement CAS module, that includes extracting all synchronisation data and immobiliser data that are matched to your ECU and Key.

Give us a call  and send your unit for Cloning / Data Transfer.