BMW and MINI Cooper CAS (Car Access System) Module Failure and repair

What is the CAS module in BMW and MINI?

CAS stands for the Car Access System. Among other things, two of the main functions of the BMW CAS module include:

  1. Enabling the vehicle to start.
  2. Monitoring the anti-theft alarm system.

CAS module generates random key code every time the vehicle is stared which it synchronizes with the Engine Control Unit, which BMW calls DME or DDE. If you have a deffective CAS module, you vehicle may show some of the symptoms below.

Where is the CAS module located?

Comfort Access CAS

For BMW, the CAS module is located under the steering column. To remove the BMW CAS module, you will need to get under the dashboard on the driver side, remove the plastic cover under the dashboard (above the brake and gas pedal). Once you remove the panel, you will find your BMW CAS module, a black or white box.

Symptoms of Bad CAS Module

  • Malfunction message on the iDrive screen
  • Key not recognized
  • The car will turn over but not start.
  • Vehicle Will Not Start  - A defective CAS module that has been damaged from water or due to low or overvoltage will prevent the vehicle from starting. Replacing the CAS module and programming is necessary to fix this problem.
  • Mismatched Key - The code in the CAS module may get out of sync with the code stored in the DME / DDE module.


If you run into a situation where you have to replace your CAS module, we are here to help.

Our 24hr turn around CAS MODULE CLONING cloning service will get you back on the road quickly while saving you hundreds to thousands of dollars.

There is no need to replace your DME or key in this situation. Simply send us your original CAS unit and a donor unit and we will clone your original over to the used or new cas unit. Once you receive your CAS module back, you just connect it back to your BMW or MINI and your car will start as normal.