4x4 Went Out - Came Back

[AlanTDickey]

One night last week after a snow, I was leaving my driveway with the Autotrac on from the previous night. As I was leaving, I realized I did not need it and turned it off. After stopping for some gas and cigars, I noted a "Service 4x4" message on the display as I drove away. I tried shutting off the truck and re-starting it. Didn't help.

In addition to the message, the little yellow light did not show up on any of the four settings: Autotrac; 2WD; 4WD Hi; or 4WD Low. I was, I believe, in the transfer case Twilight Zone. Otherwise the truck drove normally.

I called the dealer, and he told me to bring it in, but could not, would not give me any idea of what might be wrong: "It's a complicated system ...."

Called Lyndon Wester to ask if he had any ideas. He suggested that I disconnect the battery for a few seconds and then see if the problem was fixed.

When I called the, probably embarrassed, dealer's "mechanic," he said "Well, you ought to bring it in anyway 'cause it might be a temporary fix." [Though he can't look at it until next week.]

Does anyone know what was/is wrong? Why did the battery disconnect fix it?

[tmf6902]

un hooking the battery might have cleared all the codes...I dunno though...thats all I can think of

[traxion]

Possibly the switch panel is going out. That seems to be a common problem around here. Had to replace mine and has worked great ever since. Was experiencing the same probs.

[deltron]

Yep, I had the same problem. It ended up being the switch panel. Mine was fixed under warrantee, but the fix would have been $140 had it not been under warrantee.

[Chris97K1500]

Probably your switch, it's a common problem on the NBS trucks. Here's a link to a post made with a similar situation as yours. Look at Silveradoman's post http://www.gm-trucks.com/forums/index.php?...&hl=service+4x4 The same thing happened on my BIL's 99 Z71, bought the switch and I put it in. No more problems. Chris

[99silveradoz71]

Switch...had the Service 4wd light as well.

[2k3TahoeZ]

similar thing happened to me...I took it to the dealership and they uploaded a new update to the computer and it hasn't happened since.

[ajkinser]

I had the same problem. I found a place on ebay that would fix the switch, they claimed bad solder joints. I instead took the switch apart myself and found they were correct.

 

The dash board switch has two wire harnesses going to it. After I opened up the case I noticed that solder joints between the terminals that connect to the wire harness and the circuit board were cracked; the four post terminal had all cracks at all four joints, the eight post connector only had one terminal cracked.

 

I touched up the joints with some new solder and everything seems to be fine; no SERVICE 4WD yet. In all it took about an hour to complete.

[03GMCinBC]

Mine did the same thing about a month ago. After a snow and it being parked for about 8 hours. when I got in and turned on the truck, it had the service 4wd light on. Also the light assembly to the selector switch failed to come on.

 

I read on www.chevytalk.org forums that this is a common recurring problem so i took it into the dealer and explained the problem. of course, they never heard of that happening. according to them they reloaded the computer code. They said they couldnt find anything else.

 

Other members told me i should at least get it checked rather than ignore a problem that might only get worse.

 

so far so good....

 

03GMC Sierra SLT 4X4 (a work in progress)

[AlanTDickey]

Now I'm a little concerned about Westers.

Since disconnecting by battery, I have not had any problems with the 4WD, but plan to take it in to have the dealer check the switch panel under warranty.

I called Wester and aksed if there is any chance that GM will blame it on my Westers chip. Wester said that there was no way GM would even look at the chip in assessing the problem. My concern is that, my Westers chip says "Wester" right on it.

Does anyone know if GM is going to say that I have voided my warranty?