I am not an expert on Mercedes or convertible tops, but I suggest you take your car to someone who can read and understand codes. Any good Mercedes-mechanic can read these codes.

This problem sounds simple, and you don't want to spend lot of money searching for it.

I had a similar problem, and I found out it was the left window switch causing the top not to open.

The dealer read the code and changed the switch for about $125. Although, if I had known it was the window switch I could have changed it for about $20. However, I couldn't read the codes.

I am still not quite ready to invest in a code reader and book for about $200-$300. Also, there is a learning curve associated with these code readers. Good luck!