I'd like some actual tips/advice from someone who really knows the airbag system(s) and faults in Minis.

2013 R56 S Coupe, ~109K on the clock.

My airbag icon keeps coming back. I clear it (Foxwell Elite) but the OG problem remains. As the pics below show, the airbag icon shows in the central info center screen along with the seatbelt icon (both red); the airbag icon shows in the tach on the steering column; pass airbag off warning in upper console at startup; the Mini's warning explanation mentions a fault in the passenger-restraint system... (see pic). I would also note that although the airbag icon in the tach looks red in the pic, it shows as orange when the engine is running.

I search out the codes on my Foxwell and get a fault for the ACSM-MRS (crash module). Note: the car hasn't been in any accidents that might blow the airbag(s).

The particular code I'm getting is 9418 - "ACSM/MRS: Belt-force limiter, front passenger"; also states "not present". This tells me that the ACSM is not getting a signal from the belt-force tensioner (which I've found is part of the actual seatbelt spool in the door frame).

So: would y'all agree that the problem is not likely the ACSM, but the seatbelt itself? Is it possible (likely?) that the signal wire - from or at the seatbelt spool - has been damaged? Previous owner had some subwoofer wiring running under the door frame and past where the seatbelt spool would be.

Further, if it is just the seatbelt spool/limiter, is that a basic plug-n-play R&R?

TIA,
GA