The defective Skreem module was no longer recognized if you wanted to read it via obd.
So I had to desolder the processor. Then I read out the processor with my Orange5 programmer. This was fortunately intact and all data were present.
First I tried to clone the processor to another one.
Unfortunately the clone did not work completely. I could open and close the car with the key but I couldn't start it. I have to look a little deeper into this.
The processor has three areas where data is stored and I only cloned one. And it could also be that the processor was from an SLK R170.
Finally I soldered the original processor to another Skreem module, that worked fine.

Unfortunately I don't have the right hardware (Skreem, ECU and key from one Crossfire) at the moment to start more attempts.