The parts where sourced direct from my Mercedes dealership. They have said that the diagnostic machine they use only gives them basic error code's & that the van will require a more detailed diagnostic report.
I have been told that it is something to do with a sensor on the gearbox & that it will have to go to Mercedes to be recoded. I've not been told what the problem is, due to the mechanic dealing with it is in today.
I don't know if this information is of any use to you