[Cornish_Blue]

I think you are correct Lucas, CAN BUS is seeing a different module so does not understand. You car body computer needs to know it's got the upgraded seats.
As I understand it the seat controller does all the work for the seat positions and airbag, seat heat etc, body computer needs to be told to talk to the seat computer and seat belt / airbag system so safety systems still work. Update the car so it knows the new module is in there and I recon you will have this sorted. You may need the loom from the seat to the memory controls too, that's maybe the spare plug?
I think the small white plug is for the rear seat footwell lights, again turn the ambient lighting configuration on correctly and they should work also.
Keep us posted as I am interested in this also 🖐

 

[Cornish_Blue]

Some Nissan garages got trained by infiniti so may have software. Mercedes garage should have software. Try independent Mercedes garage with coding experience and you might get lucky? It's the star C4 or C5 we need I think.

 

[Cornish_Blue]

Hi Lucas, thankyou for the update. So we were right, item programmed correctly and all is well again 🖐 do you know what software your friend used?
Great news.