I spent some time messing around in snowy fields,just goofing off,,in 4 hi lock, then drove about 2 miles on wet clear roads,IN HI LOCK i guess. yes me the guy who screams about it!!.
later i drove again on snow and noticed "check 4wd" or svc 4wd, on the dash.yikes,i couldnt clear it with the lock /hi buttons even though i was in 4hi open,not locked,i drove in circles forward,back to no good.
finally turned off key,counted to 7!,restarted and all is well.
yes i went to hi lock,lo lock,locked diffs and back to open 4 hi.

aok,jfwiw,,,whew!!
dont know why?.really gotta watch lights, yes me