Although they are mostly SLK320 under the sheet metal the general forum member feedback has been that Mercedes dealers refuse to work on our cars. I hope Luigi has a relationship with the Mercedes dealer so they will look at it. I don't know if the Mercedes diagnostic system will read the Chrysler SKREEM module.

PM me if you get stuck on this. I have a Chrysler DRBIII which reads the SKREEM. Luigi's Gulf is halfway between where I work and live. If Luigi's Gulf is interested I would be willing to bring it over so we can read what it's seeing with the SKREEM. It has a module replacement function, but I have never needed to use it, and the documentation is incomplete as to how that works, so I'm not saying I can solve your problem.