Well I've had my h3 for a week now and noticed yesterday since the weather got really cold - yet again- that there was a cherp. I figured something needed to be greased or new belt. So I it by the dealership who fixed it in 20 minutes-new belt- no charge. Very happy--- but then I got home and decided to try out high and low in my open field and got the Serve 4wd message and it would not go into either or disengage/engage traction control. Took it by to the dealership who had it for 4 hours called back and said they would need to keep it for at least another day as they have to take the transfer case apart to find out the problem. He assured me all of this was covered under warranty.

Anyone else have this problem with 4wd and did you continue to have problems after the fix

 

Every once in a while my truck will say Service Traction, Service 4wd, but it goes away after I restart it...I dunno what it is but I would like to see what happens with your truck

 

I get CE light everynow and then. I have a Service TPM message a couple of times but goes away. The only time I had a Serv 4wd message was when my ignition control switch fuse went out (#5)... but the whole Hummer wouldn't even start then.

 

Some of the transfer cases had a plastic mode shift fork which was prone to failure. This was replaced by an aluminum fork in later models. By the way, how were you trying to disable traction control? Only reason I ask is that I just commented on a recent thread regarding traction control. Different people have different results. Personally, mine can't be disables (2008 / MT). Just curious of your year, tranny, and method of disabling it.

 

For the traction control I just went by how it says to disengage it in the manual. I have an 08 alpha. I was in the field trying to switch between the different 4wd locks and wanted to see if it was working as well. When I mentioned it to the service guy at Hummer he said the traction control wouldn't disengage unless you were in one of the locked 4wd... so maybe that's why it didn't work. Either way I'm going to have him check it all and clarify. I would imagine that Carmax checks their used 4wd before they sell them, but it seems like they should've caught it. I can't wait to get her back working-it's aggrevating because it's a NEW (used) car to me, but I do have every confidence in the Hummer mechanics.

 

Let me go ahead and say I should've caught it as well on the dealer lot, not just rely on the dealer. I made the mistake of assuming since it's 4wd all the time there shouldn't be any problems switching between the levels of 4wd- not like a 2wd to 4wd, but I'm new to the world of 4wd so live and learn and thank goodness for warranties. :-)

 

First of all I wouldn't rely on the dealer to catch any malfunction in a vehical that wasn't blatantly obvious, much less expect most salesmen to bring it to my attention. You say you are new to 4wd so I don't find it unusual that a malfunction in a system that you are totally unfamiliar with could escape your attention. Furthermore having experienced the shift fork failure myself (20+years of serious 4 wheeling exp.) I can say that it is not really obvious with the H3's full time system, when the shift fork fails and it won't lock. I ended up fighting with dealer service dept.'s because they assured me that it was working like it should. I would also like to say that my shift fork failure would not give me a service 4WD code, and I know of others who have had the same failure that the vehical system didn't detect, so unless you're real familiar with how the vehical should act in the various modes you wouldn't even know that it wasn't working right. With that said I think that there is a good possibility that what you're experiencing may not be a shift fork failure, especially since yours is an 08(although if it is in an 06 or early 07 it needs replaced anyway IMO). Anyway good luck with getting it fixed.

 

Some dealers provide a free carfax report. Sorry to hear that your hummer stop working the way it should for you.

 

My wife just tried to take my 06 through a 5-1/2 foot compacted snow mountain... got stuck and my son tried to engage the 4 low... boom now it says serv 4wd traction failure. Buddy of mine said to check for loose wires since the transfer case is electrically operated and at least in the 06 the connection is exposed to the elements (bad design in my opinion). Letting her dry out so I can try it again but now wonder if I just need to reset the thing to clear the message? Anyone have any input? We got 30 " of snow last night and I am stuck at home wo 4wd ....bummer for me and my hummer.

 

Almost all 4WD's that have anything but a lever on the floor with linkage to the t-case to engage it, have an electrical connection that is exposed to the elements at the t-case that applies power to the motor that switches the t-case. I agree that it's not the best idea.

As for resetting the fault code, after the computer sees so many key cycles without the code it will usually reset itself. I'm not sure how many cycles it takes but it's not very many. I was messing with the wiring on my locker and started it without the locker wiring plugged in and it threw the service 4Wd code, and then reset itself after I plugged the wires back in. It did store that code in the computer history and the dealer was able to retrieve the code later on.

I would cycle it a few times and if the code goes away take it out and try it.