My thoughts exactly. I’m thinking that the 05-12 Pathfinder LE’s, when in 2WD, do not have the front transfer case engaged at all.
There’s no hub lock or unlock on these. Unless selecting 4WD is what you’re referring to by manually locking the hubs.
AWD is a confusing on this vehicle. I don’t think that the hubs are technically locked, but they’re obviously engaged, and the drive is put to the front by “The System” when it senses “Slip” I guess. And if your front tires are mismatched, it might sense slip continuously.
I guess that I could put the truck up on the lift, start it and engage “Drive”(2WD), and just see what’s spinning. I would assume that the forward drive shaft always spins, but that the transfer case is not engaged.
Another way would probably be to put on the new front tire on the front paired with the used front tire and go drive. If it’s a problem, the “VDC” and “Slip” lights would probably come on.