2003 W209 CLK, 2005 R171 SLK, Volvo XC40 P8 Twin Motor Pro EV
If its a mercedes becker unit then the dealer should get you the code easily. If not lots of outfits on ebay will supply it if given the serial number.
Which car is this from.
I had the same issue, went to main dealer and they passed me to a specialist.
He said that there is no code just remove main fuse to radio wair 2 mins and replace .
Worked for me.