It is a duplex.
We changed the car io board, and the errors went away, except that the doors would close on their own, and not open when commanded (this wound up being the Lust door drive).
We had the car running normal, then went back to try the original car io board, and then the LON problem popped up.
I cant see how the original car io board could have taken out communications, as it did communicate before we removed it.
We tried discharging the cap, and reseting with the car on MR inspect, but the LON error pops up on startup ever time.
We can see that the car io is communicating using the test LON menu, and hitting the service button on the car io.
I was thinking afer I left that maybe the selector talks via the LON buss? Maybe thats what isn't reporting in?