When Program BMW CAS3 keys, we often suggest to take photos and record the CAS version code. In case of programming interruption, the OBD data can be repaired according to the recorded version. As well as FEM\BDC, suggest to record the key information read after connecting the vehicle.
As you can see VVDI2 BMW FEM/BDC Key Learn pic, the key info display “VIN, SWFL, TLD, CAFD, IMMO Type”
If there is an error in the operation, you can know which part has a problem.
If the value of SWFL becomes 0000 000000 FFFFFF or 255 255 255, there is a problem with the programming file, and you need to use BMW programming tool to program the FEM/BDC. You’d better select the previously recorded version of SWFL to write into a new file for programming. (Or choose a version with a small span between the previous version).
If the data of CAFD becomes 0000 000000 FFFFFF or 255 255 255, it means that there is a problem with the coding file. You only need to restore the coding or use coding tool.
After understanding the content of SWFL and CAFD, we can treat them differently when we encounter problems, avoiding programming and coding all the time no matter what problems.