Failed Blue & Me module which is under the drivers seat in the RHD version. Search on here for various threads - unit can be repaired in the UK these days. Chances are it has failed "on" so provides a parasitic drain on the battery - flat battery in 2 - 3 days if car not used. To avoid this disconnect under the seat - not at the radio head unit.
My experience is that this is a myth, no proxi alignment required. I fitted a second hand Alfa module - it was plug and play. This has been confirmed by FiatWorkshop at Royston too.
Cover is held on by two plastic "plugs" that look like old school wooden clothes pegs when removed. Removal is by using a plastic trim tool behind and easing outwards (a small metal screwdriver will do the job if you don't mind "bruising" the plastic). The cover then comes off. From memory there are 4 10mm A/F bolts holding the module to a metal frame. Push the seat all the way back to get the front pair then I think I pulled the set forwards and got the second pair from the back seat. Electrical connection is what you might expect - multipin socket.
Revtronic came up trumps for me, although I did require the proxy realignment thereafter before the odometer would stop flashing. Good luck with it
Yeah, the proxy realignment thing seems to be a variable feast. CanBus architecture and function is not my thing, as mentioned my experience was that it wasn't required but this was for a second-hand Blue&Me unit so it would probably have an address written to the firmware whereas a new or repaired module perhaps behaves as a virgin unit and needs some coding? I am speculating now.
I think that your speculation is probably correct ( but I'll readily bow to the expertise of others if I'm wrong
).Yes, me too, I prefer to only share actual experience on here - but then mine was I didn't need a poxy(I think that your speculation is probably correct ( but I'll readily bow to the expertise of others if I'm wrong
) re alignment