Stuck in 4HI!!

Hi everyone! This is my first post, but im visiting this site often, 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!

Someone? Please!

it might be a bad transfer case shift motor, it's the electronic motor that changes your drives for 4hi, 4 lo, ect. you could try tapping on the solenoid with a hammer to see if it helps while trying to shift. I'm just a student so i'm new at this but it might help. also try puting the car in nutral on a flat surface ,holding the brake, and try to take it out of 4 wheel drive.

Hi I had the same problem but after playing with the 4 low back and forth to 4 hight it went to 4 hight after I played the same with the 2 weel and it went...After $1000 of testing it turned out to be the transfer case shift modual located in the foot panel on the pasenger side. Dealership said it was rare . Had the Mechanics at the delership scratching their head.. Other symtones i was getting it was runing rough verry hard on gas still is but not as bad lol Hope this help

Had similar prob with my 95. Every on said Encoder Motor. Ended up being the Transfer Case Shift Module. Picked up at salvage yard for $50. Hope it works for you.Also, if your stuck in 4wd, to get it back into 2wd try this: start truck, put in Neutral, press 2wd, while switch is flashing put in P quickly. Works on 95 & 96 maybe yours too. good luck

Hi everyone! This is my first post, but im visiting this site often, 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!

I had the same problem. I have it fixed at least for now. What I did was to disconnect the battery, remove the door strip by carefully pulling it up by hand and then removing the kick panel on the passenger side. I removed the three nuts to remove the shift module. I then carefully unplud the connections using a fine bladed screwdriver. I found that some of the contacts were corroded so I cut a piece of sandpaper into a strip and folded it over and used a fine bladed flat screwdriver to sand the corroded contacts. I used a jewelers flat bladed screwdriver to clean out the other side of the connections ( female side). I sprayed both sides with WD40 and dryed off the excess. I then coated the pins with vasoline before reconnecting everything including the battery. My vehicle now shifts in and out of FWD. I hope this helps! Ken

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