Okay, so I tried calibrating steering sensor. BT enthusiast (the cheap, 3 VIN version) does have this function as you noted above. Did it per your instructions, but it didn't fix problem. I think it's that servo motor. Dang! I was hoping this would work. My error comes up as soon as you start the, without moving it or putting it in gear, moving steering wheel, etc.
BTW, when I scanned errors using BT tool, I did not have a steering wheel sensor error, but I still have that transfer case error - clutch position unknown error. Cleared all errors, started car, and scanned again and transfer case error still comes up (as well as the Christmas tree set of lights on dash).
Well, it was worth a try. Car runs and drives fine, albeit in 2wd and no ABC, no DSC, etc. Just have to see if I want to replace transfer case to get rid of errors.