CAS Replacement in BMW E Series

BMW E series with CAS
BMW E series with CAS

How To Replace a Damaged CAS From BMW

The car access system is responsible for the safety and leisure operations in BMW models. The CAS act itself as the immobilizer unit for the security of the vehicle, it stores the DME/DDE ISN, EGS ISN, Key data and other critical information.

A transponder chip is integrated with each of the vehicle keys. The key sends data to the CAS with the help of a ring coil in the key slot unless the data is recognized by CAS the car will not start. New versions of CAS encrypt the DME ISN and EGS ISN, they can be decrypted only with the key information.

The vehicle order (car configuration) is also stored inside the CAS control in the E series and stored as a backup in case of the F series. CAS also has its own security number inside which should be matched with DME/EGS for proper working.

Autohex allows for editing this security inside CAS and matching it with other controls. So, because of this, you can replace all models of CAS up to CAS 3+ with a used one for any car.

If the old CAS is alive and can read data from it, the CAS replacement option in autohex will do the job in just one click, just need to follow the steps as given by AutoHex. Just need to connect the original CAS first and go to CAS replacement menu and proceed. Then the software will ask to connect donor CAS, this way it can be transferred the ISN, VIN, and other major data including the key.

Autohex Automated CAS Replacement Step 1
Autohex Automated CAS Replacement Step 1
Autohex Automated CAS Replacement Step 2
Autohex Automated CAS Replacement Step 2

If the working CAS is not supported in CAS replacement and wants to use the same keys for the new unit you must save the key data from the option1 in key learning and that key data can be used to program the same key to the new CAS without renewing the key.

CAS Is Encrypted Or Not Responding

In general, the steps for the replacement of CAS by Autohex:

  • Get a working CAS with a valid key.
  • Read DME ISN and write it to CAS.
  • Restore FA from LM to CAS from the FA manager.
  • Change VIN for CAS from the advanced option in CAS replacement.
  • GO back to the main menu in the software.
  • Start again with coding/programing.
  • DO coding for CAS.
Autohex II Modify CAS VIN by OBD
Autohex II Modify CAS VIN by OBD
Autohex II vehicle order Manager
Autohex II vehicle order Manager



Last Update: 6/6/2022
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