Well for the last month or 2 my 4wd has been out of commision, borroed a cousins snap-on scanner and gave me code u1026, still havent gotten around to fixing it yet cause of the crappy weather but heres the possiblities I have gathered so far, kinda of a check list for me and other people with this code
-TCCM reflash
-TCCM replacement
-4wd button replacement
-Cold weather= ice, snow, slush on wheel speed sensors
-30amp TREC Fuse (unplug for 30 seconds)
-Encoder motor
-Encoder motor sensor
-ATC Fuse 20 amp fuse ( replace with 25 amp fuse)
-Replace Circuit 1640 (18 guage orange wire) with (16 guage orange wire)
-Driver side cab mount frame ( check for lose or corroded ground wires)
-Ground wires behind power steering pump on engine block ( check for corrosion or loseness)

Thats all I got for now