I cannot offer any solid advice on your particular problem, perhaps someone else can. However, I had a similar problem with a 2009 W204 C220cdi sedan in which several functions would stop working and the car would go into limp mode. In my case it would not correct itself by a restart but going through a bump usually helped. Later, just leaving the car standing for half an hour, it would heal itself. Advice ranged from a loose earth to a suspected Signal Acquisition Module (SAM). It turned out that the main power supply cable to the front (in the engine compartment) SAM had a poor connection, upset by bumps and temperature changes. Its a R50 connector with a plastic clip. However, after fixing the connector there were still issues and I eventually replaced the R18,000 SAM with a used part bought for less than R4,000.
