Stuck in 4HI!!!

[mtommy79]

Hi everyone! First time poster long time reader, and i need your help now! So i have a 2000 GMC Jimmy 4x4 and my problem is the 4WD service light came on and the truck went to 4WD!
Now i can't change it, i press the 2HI button start to flash i can hear the sound under the truck(TC) then a clicking(TM) at the passanger side
but after it goes back to 4HI. Same with 4LO, i can't change it!
My question is before i take it to the mechanic is what do you think what is the problem? Vacum switch, encoder motor ......?
What i did today is i took the 4WD ATC fuse out (under hood) then i started my truck and i can drive feel like relased the front axle im guessing went back to 2WD. Is this solution gonna cause some problem?
Im ok to drive the truck like that?
Tryd disconnecting battery = nothing.
I don't know much about cars, that's why im asking so at least if i go to a mechanic im gonna have some clue what is wrong!
Thanks!

[mtommy79]

Someone, please?

[ricksza]

Sounds like a transfer case selector switch or a transfer case control module. Will need a scanner to monitor the shift request data.