In US. New to me SLK230 had oil leak and took it to the dealer. For free they installed the wire harness adapter and all parts that had oil at the connector. This included the ECU, O2 sensor, and MAF. But, they did not replace the sensor - go figure. So, I ordered a new one ($80) and installed myself. No more leaks.
I still have an issue with going into limp mode if you floor the accelerator all the way. I have an auto. Disconnected the downshift switch on the accelerator and it still goes into limp mode. No codes. Have new pedal assembly coming tomorrow.
When in for the cam sensor, dealer said transmission lines were leaking and transmission control unit not working. After I cleaned up everything from the oil leak, lines are not leaking. Don't know about TCU but no codes being thrown after reset. Hope this isn't what is causing the limp mode (cost is $600 for part plus programming.