4 High Lock Won't Disengage!!

How's it going? Long time reading, first time poster. This is the problem I'm having. My H3 for some reason today decided to go into 4 High Lock on it's own while I was trying to park. (I suppose the lack of off roading finally fed her up!) I pressed the "All Time 4x4" button and it lit up but I decided to drive out of the parking spot and see if the H3 was ok. This is when I noticed that even though the "All Time 4x4" button was on, the H3 was actually still in 4 High Lock. Called the dealer and the tech advised to drive it in reverse for 20 ft and then see if she's ok. Did this and it worked, but I wasn't sure that fixed the problem so I put her back into "4 High Lock" and drove a bit then back to "All Time 4x4" and again still in 4 High Lock. She's scheduled to be looked at but I was wanting to know if any more experienced "Hummer" owners have experienced this and what the problem was.
 
Appreciate any responses.

Mine jumped to the second position over the weekend.  I don't think so but I may have accidently bumped it.  Anyway I switched it back with no problems.  I didn't see the light on but noticed my tires were scrubbing, a sign of a locked differential.

Didn't someone else here have a similar issue and it turned out to be the tc motor needing to be replaced?

I'm curious as to what tires scrubbing means.

That's when both tires are turning at the same rate and the inside tire trys and does continue to turn at the same rate as the outside tire does in a turn...That's why limitied slip differentials will let the inside tire stop turning in a turn and the out side tire continues to pull...The result is exsessive wearout on the tires and strain on the differential...also for this reason, you should not engage the lockers unless you expect to be driving in a a straight line with little or no turning on hard pavement.

D VADER, I thought I might of accidentally hit the button also but both my hands were on the steering wheel since I was making a turn into the parking row.
 
As for the TC motor needing to be replaced, thank goodness for warranty!!
 
I appreciate the replies.

"All Time 4x4" button? Am I way to paranoid about trolls? If its true: Take it to the dealer, its clearly a malfunction that you wont be able to fix on your own. 

Hummer Guy, I appreciate the reply. As for being paranoid about trolls, No I'm not. As you may have read in the my first post, I'm new to the forums and was asking for those who have owned an H3 longer than I have if they have experienced this issue. The "All Time 4x4 button", I was referring to the button that is active during regular driving. I appologize for not reading the manual for the actual name/label of the button but it looks like everyone else who replied knew what I was talking about. I also mentioned that the H3 was scheduled for maintenance so clearly I knew I couldn't resolve this issue on my own. I appologize in advance if I read your reply as a "Negative" response to my lack of knowledge of the 4x4 system but I've come to realize on any forum that there are some folks that like to degrade those who are just asking for what "you" may consider as "Common Sense" information.
 
As to the condition of the H3, the tech checked it out and all was good. Apparently, 4x4's need to be placed in reverse after switching back to "Normal" driving and driven 20ft. Is this true? I don't know, but maybe you, "Hummer Guy", can answer this for me.

Hey Joe..I never heard of that before..I cycle mine through all the 4x4 functions while standing still in neutral and they always return to normal...Sound like it ain't working right for you still...

Same here.  In neutral, I can cycle between them all fine.  At low speeds, the 4-Hi and 4-Hi locked always works as well.

Some how the truck was in 4X4 lock (high).  since the daughter was driving it the day before I'm blaming her.  I haven't tried it but I assume it stays where you last left it.  I didn't notice it untill I had driven about 10 miles (first 3 on dirt) and turning into a parking space.  I think that binding it up like that makes it harder for the gears to just release.  Even in the manual it state you may need to back up to release the gears so it can go back into 4X4 normal.  Seems like the biggest leson here is to check the position of the lights before driving.  It's so easy to bump that button  and even if you didn't the previous person may have.