Foxflash read and write Mercedes Benz Sprinter EDC15C6 via OTB mode successfully.
OTB adapter is a great help.
Mercedes Sprinter with a round OBD plug that requires an adapter.
Simple and easy with the help of OTB.
Check EDC15 C6 bench pinout
Select Car OBD, Mercedes Sprinter CDI E3 EDC15C6 protocol
Checksum manually with Winols.