Sounds like the T case is stuck in neutral. I know very little about the workings of the electric shift. I would start by pulling the transfer case motor and see what is happening when you push the switch. Before that, pull the ground wire and clean the frame off where it connects underneath the drivers door. That ground seems to cause a fair amount of issues.

 

Thanks for the ideas. I just cleaned the ground wires and frame. That didn't fix it. I'll see if I can figure out if the transfer case motor is doing anything next.

 

I hear nothing at the transfer case motor when I turn the switch. I can't fit my voltmeter probs down in the little connector slits to see if the motor is getting a signal.
Would this seem to indicate that the problem lies in either the selector switch, the transfer case control module or the transfer case motor?

 

Don"t pull the transfer case and try switching positions- that will ruin the position switch in the motor.

 

Good to know. I had considered doing that.

 

You could try a relearn. If I remember the dial will rotate to the right past 4lo. hold it there for 30 seconds or so and you will hear the transfer case cycle through all positions. It's a long shot, but worth a try. The motor is usually the problem. If you could get the code the case is setting it would help. I believe some codes will not allow a relearn.

 

I haven't run across that little trick. As you say, it's worth a shot. I have a motor, switch and control module ordered. I don't have a code reader and 20 miles to the nearest shop, but I always think I really should have one at times like these. Motor problem is the way I'm leaning; it's good to hear someone with more experience offer some stats. Thank you.

 

I replaced all parts yesterday and truck still won't move. First the transfer case motor, then the TCCM, 30 amp fuse and finally the 4WD selector switch. The initial conditions still exist (truck won't move in any gear, service 4WD message, will roll in Park, no light to indicate the position on the selector switch, brief grinding noise when the truck is running and you shift to park). On the initial startup after replacing the TCCM there was the brief grinding. There was a note on the TCCM that said to connect the 4 pin connector last to prevent communication errors. I followed this step.

Any other ideas? Any ideas on what is causing this grinding noise I'm hearing when shifting back into Park? I've started shutting off the engine before shifting to Park to avoid the grinding. Also, I'm working by myself so it's hard to say exactly where the noise originates.

Thank you.

 

Because I didn't hear the transfer case motor trying to work, I was thinking the problem was motor, tccm or selector switch. After replacing all those parts, I've had to expand my search for the culprit. I drained the transfer case fluid and found three little pins attached to the magnetic drain plug. They look like the pins that hold the links to the transfer case chain together. Does this look correct? I'll try to attach the picture. If so, would a broken chain cause the problems I've described above?
As ever, thanks for any guidance. I only learn about the mechanics of things as they break. I think this truck will give me quite the education.

 

Large pieces like that on the magnet are not a good sign.
You're going to need to pull that transfer case and do an autopsy.
They really aren't terribly difficult to yank out and open up.

 

After a little more research on the chain. I don't think the size of what I've found is quite large enough. Maybe the metal pieces are from a needle roller bearing?? Either way, it looks like I have some trouble in the transfer case.

 

Dang.... They look a bit short to be chain pins but maybe roller bearings?? They look smoked! what did the fluid look and smell like?

 

The fluid was dark but didn't have a burnt smell.
I don't have a transmission jack and while, with the help of gravity, I think I can get the transfer case removed I'm not sure I can get it lifted back up again. Time is also getting to be a factor. I'm going to have to consider hauling it to "twelve hundred dollar Tony", which, if he lives up to his name, might be a deal this time.

 

If you have a floor jack at least, you can buy a transmission adapter plate to fit in the hole where the jack saddle sits. Then it is a one man job when you get the transfer case sitting in the adapter properly to mate to the tans. Replacing all mating seals and gaskets while they are apart is best option also.

 

I pulled the t case off mine by hand, not horribly heavy. Floor jack works too. If you have time to rebuild it you would need to pull it off and check for damage, them order the parts and I dont know if there are any update parts for these. Last one I did the local really good chevy dealer, with a commercial parts department, had one in stock that was cheaper than anything I could order from any other parts house. I never have time as mine is my daily work truck so it costs money just to have it down.

 

My brother loaned me his little run around farm truck. So, I guess I'll try rebuilding or replacing the transfer case after all. I picked up a transmission jack on the way home. Thanks again for all the help. All I know on transfer cases is what I'm learning here on the internet.

 

Hey Ericakc, did you ever get this fixed? Mine is doing the same thing. Hoping you could share what ended up happening.

 

Sorry for the delay; I thought I'd get an email if someone posted on this thread.

My problem is ongoing. I took the transfer case apart and couldn't really make heads or tails of what was going on in there. I didn't find any more needle bearings. I'm assuming they were debris from a previous rebuild.

I ordered and installed a new transfer case. The truck now moves but is stuck in 4WD and the "Service 4 wheel drive" message is still in the DIC. I picked up a code reader along the way but it doesn't show any transfer case codes.

Still, no lights are illuminated on the transfer case selector switch after the initial startup. I'm thinking now the problem is the tccm...either it isn't able to relearn or it was bad to start with (it was a remanufactured Dorman). I also ran across one post on the internet that said the tccm isn't able to relearn if there are any other codes present. I do have a "low efficiency in the catalyst system" code. I tried reinstalling the old tccm with the new transfer case...No change.

It's been a while since you asked your question. Did you find a solution to your problem?

 

I've got an 08 doing the same thing, did you ever get anything figured out?

 

The last piece to my situation listed above was the tccm that they sent me was the wrong RPO code. I had to take (haul) the truck to the dealer and have them reprogram the tccm to my RPO code. Another $100. Good luck with yours.

 

Did you ever solve this? I don't have this issue, but am doing research for future problems to avoid and am curious if you found the culprit?

 

Any luck on repairing your truck. Im literally have same issue, word for word, as you. Lol.
Last i saw was the pins you found in your transfercase drain.
Was that it?

 

I'm having the same problem ...any advice on how to fix it ?

 

My entire saga is contained in these three pages of posts. If that's too much to read through, here is the short version:
I changed basically everything associated with the 4 wheel drive. My problem turned out to be the transfer case. It was beyond my skill set to rebuild the transfer case. I bought and installed a reconditioned one. After this, the truck would move but still wasn't right. My truck was manufactured in Canada and has a different RPO code than most made in the states. The transfer case control module that I bought was the correct one but had to be reprogrammed to get it to work correctly. I tried putting in the old TCCM but that one didn't work either. I did try about 1000 re-learns on that, so may have screwed it up. I was told, by the owner of my local repair shop, that the reprogramming needed to be done by a dealership.
It would have been nice to know exactly what the problem was before I started changing parts. I wasn't able to figure out how to do that short of hauling the truck in for diagnostics, which I couldn't do at the time. While the changing of a transfer case might sound daunting, I found a couple of videos on youtube that weren't exactly like my truck but seemed similar enough that I felt confident in trying it myself. I did it by myself and didn't have any major difficulties. I'm a 50 year old woman with very little auto repair experience, but I can follow directions. Good luck.

 

Have you disconnected the battery while key on ? It worked for a guy I worked with,