2002 stuck in auto 4wd??

So here is my problem. I just bought a 2002 Lt 1500, i have put 4000 miles on it(it's now at 16,000) I put it in auto WD last week, just for a half hour and when I switched back to 2 wd, the 2WD light came on but it is still in auto 4wd??? The light does not give the normal 3 blink when going back into 2wd. I have tried cycling through all of the options. 4lo works, 4 hi works and auto works but when i go back to 2Wd it stays in auto 4wd (front axle is engaged). Am I missing a step or is something screwed up?? Thanks

hadto take my 2000to the dealer and they replaced the switchs