C270 CDI Transmission Problem
 

Hi. I have a MB C270 CDI (2002).
The Auto transmission is free reving when changing between gears 3 and 4 and occasonaly goes into limp mode (stays in 2nd gear) when it does this if i turn off the engine and select park and start car again it comes out of limp home mode.
I have had it at the dealers and they have hooked it up to the dianostic machine but cant find a fault. The recomended overhauling the box, which I did. I am still having the same problem. I occures more when the car is hot. Please help.

Regards