Right gentlemen
I think I may have had a bit of luck, after stripping practically everything out of the rear of the car and having no joy with connections etc, I then removed glovebox to check connections to the junction box which, again all seemed clean and dry, I then went under the seats and started checking, under the n/s seat just seems to be a tv module or poss telephone module, either way no can bus wires to it, then under drivers seat I found the seat control module (climate seats) with plenty of can wires to it.
I disconnected this and tried again, now the only codes I am getting back are the speaker codes, which have been pretty much hard from the start.
I have road tested, although only five or so miles and still no communication or med speed can bus codes.
Obviously the climate seats no longer work but everything else seems to have healed up!
The question is could this module, either shorting or open circuit, cause this sort of catastrophic failure ? also, why would I get no climate seat codes when disconnected.
Thoughts please
