4wd switch

digdoug2 · December 12, 2005

I have a 2002 trailblazer EXT 4wd with 50,000 miles. The 4wd switch does not work. Nothing happens when I turn it to AWD,4HI or 4LO....no light...no noises...nothing! I have asked around and found that it could be the switch and/or the computer needs re-set and/or replaced. Is the switch something I can replace? Is re-setting the computer something I can do? I am not a certified mechanic but I typically do all my own work. Is the part number of the switch 1S3164, which should cost around 20 bucks? Thanks, Doug

GM-Tech · December 12, 2005

There are several conditions that could be occuring. It'd help to know what DTC's, if any, are present. The switch problem is only on the full-sized trucks, not the Trailblazer, though that doesn't mean the switch can't fail.

You can first try pulling the fuse (labeled ATCM or TREC) in the underhood fuse box for 30 seconds and see if that restores it. If so, you probably need the TCCM (transfer case control module). There's updated programming to correct this issue, but on the 2002, you have to replace the TCCM.

Basically, need more info.

busta · December 12, 2005

On my wifes o4 S-10 blazer we have replaced the switch and just last week we had to replace the sylinoid (sp?) on the transfer case...same exact thing was happening to it that you described so it might be that...it had the same symptoms both times

digdoug2 · December 15, 2005

thanks GM-Tech...I do not have a diagnostic tester for this new of a vehicle yet, so I can't tell if there are any codes stored. There was never a trouble code light intil now. I removed the ATC fuse and re-installed, like you said. Now the service 4WD light stays on. Also I noticed that the 4WD switch illuminates several yellow dots during start up but then they all go away after a few seconds. It did not do this before. Still nothing happens when I turn the switch to any 4wd setting. Does this point to the TCCM? Do I need to get the codes read? Is the TCCM something I can purchase myself and install? I hope I am giving enough info.....I'm trying...thanks again, Doug

GM-Tech · December 15, 2005

It does sound like it could be the TCCM, but I don't want to tell you to go out and get it replaced and waste your money if it doesn't fix it. Sure, you could put it in yourself, but it has to be programmed, which would require a trip to the dealer.

digdoug2 · December 16, 2005

Went to the GM dealer yesterday, they checked for codes and found none. They re-programmed the TCCM. Cost $73.00. On the way home the service 4WD light came on again. Took it out again later and the service light was off and the yellow dot was on the switch, it was in AWD and appeared to be working correctly. This morning there are no lights on the switch and the service light is on again. I told them that you had said to replace the TCCM because it is the 2002 model. They said don't believe everything you hear on the internet. So now it appears that they will have to replace the TCCM and charge me again to program the new one. It is there now....I will let you know the outcome.

just got a call and they said the encoder motor(sp?) and TCCM need replaced. Cost $525.00. I am not happy with the whole Trailblazer 4WD system. I have owned many GM 4WD's and never heard of such problems. The more I look around, the more I see the same problems with these new systems. Do you think there will ever be a recall on any of this?

busta · December 16, 2005

The trailblazer 4WD system must be the same as the S-10 4WD system...in which case they both suck...i have had my wifes S-10 Blazer in several times for the swith and the sylanoid and to reset the computer so I am just waiting for the motor to go out now...oh well

GM-Tech · December 16, 2005

They said don't believe everything you hear on the internet.

Which I have to agree with. When a customer comes in here with a printout, you hear the... "Oh boy, here comes another one with something he found on the internet."

I have owned many GM 4WD's and never heard of such problems.

If they weren't electronically controlled, then that's the difference. When you start throwing electronics into the mix, there's always the potential for some small glitch to cause major problems. It ain't like grabbin' the big old stick on the floor and shoving it into 4WD manually. Not much can go wrong with that.

No, it doesn't seem likely there'll be a recall on this. That's a common question we get for just about every failure. "Isn't there a recall on this?" The fact of the matter is, if they recalled every vehicle for every little failure (even though $$$ wise, it ain't little to you), GM could just close their doors.

If thousands and thousands of the same vehicles were having the indentical failure, then yeah, maybe they'd have a "special policy" or possibly even a recall. I have not seen a single 4WD failure on a Trailblazer, but I will say that we don't see a lot of 4WD Trailblazers down here in the land of no winter.

Z71Rider · March 10, 2007

The trailblazer 4WD system must be the same as the S-10 4WD system...in which case they both suck...i have had my wifes S-10 Blazer in several times for the swith and the sylanoid and to reset the computer so I am just waiting for the motor to go out now...oh well

I've been a GM man all my life. I am seeing more and more issues with their trucks that GM has to be aware of...they just don't want to fix it at their cost. Let the unlucky customer pay. My current 02 Silverado shelled a reactor shell in the tranny at 52000 miles. GM covered half. So, $800 later, I'm on my way. The mirrors are heated when the rear defrost button is pushed. They both were replaced under warranty, and now neither work again. I will not pay the cost to replace...just no defrost on the mirrors. The drivers side power window broke...$370 there. You know what? If I'd wanted Ford and Dodge quality....I'd of bought one of them. Now the Service 4WD message is coming on. I'll take a $40 chance and replace the switch. If that doesn't fix it...goodbye Chevy. I'll be at a Toyota dealership for a new Tundra. And GM will have lost 2 more customers...me and my wife. The real pisser is that GM knows about all these issues I've mentioned, as problems that are happening to customers way, way, too often.

Message for GM: If you want to stay in business, you'd better start working on making your customers happy. That includes fixing repeating problems...what could be identified as design problems...at your cost. The customer has spent alot of his money already on your product. Don't soak him for more just because it may cost you some money. Then, fix the design problems.

Or, you will soon be following Ford down the path of bankruptcy. And, Toyota will have a higher and higher share of customers that used to be yours.

WAKE UP GM!!!!