2011 R350 HU engineering menu
It took me a while but I figured out the engineering menu combo for my 2010 R350. Give this a try; it might work on your 2011.
Start the car and set COMAND to radio. Press the red "phone down" asterisk, and number 6 buttons together and hold them down for about 15 seconds. The system will enter engineering mode.
Good luck!







