4x4 Not Working AGAIN - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

Welcome Enthusiast! If you already own a Chevy TrailBlazer or GMC Envoy or perhaps thinking of purchasing such a vehicle, then you have come to the best TrailBlazer and Envoy site on the net! Rainier, Bravada, Ascender, and 9-7x owners welcome too!

You are currently viewing our site as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to search and post topics, communicate privately with other members, respond to polls, upload content, and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.
Join Today!
Go Back   Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum > 2002 - 2009 TrailBlazer/Envoy Tech > 02-09 Vortec 4.2L I-6 Engine and Drivetrain > 4x4 Drivetrain

4x4 Drivetrain 4x4 Repairs & Problems

TrailVoy.com is the premier GMC Envoy Forum on the internet. Registered Users do not see the above ads.
Thread Tools
Old 12-07-2018, 05:18 PM
2006Envoy1 2006Envoy1 is offline
Junior Member
2006 GMC Envoy SLE
Superior Blue Metallic 4.2L I6 4X4
Join Date: Apr 2017
Location: Manchester, NH
Posts: 7
4x4 Not Working AGAIN

Hello all,

I know this subject has been covered so much but I still cannot find an answer, so here goes with a little history of my problem.

I got the vehicle about 18 months ago and I now have my 4th bad Encoder Motor.

1st (Within the first 2 months of having the vehicle): The fist one shorted out when shifting out of 4x4 during a snow storm but my front diff never disengaged and that's when I knew I had an issue. I got a junkyard motor and confirmed the old one was bad. About 1 month after the motor had died.

2nd (Same time frame): The junkyard one, while installing, shorted out per the mechanic that installed the 3rd one.

3rd (At the beginning of the 2017/18 winter): Used it maybe once or twice before and then that one shorted out. Mechanic said he fixed the short and it should be fine. Now on the 4th one roughly 8 months later

4th (Used multiple times since it was installed in mud and other mild terrain): This one lasted for quite some time until about 2 weeks ago when I needed it for something besides going off road and snow and it failed again on me.

I have just come in from doing the "go to fix" buy disconnecting the battery for 30 minutes and pulling fuse 8 from the front fuse box and 48 from the rear. Nothing improved, I am still in Auto 4x4. The only noises I hear when trying to sift to any other configuration is the relays. I'm not sure if this could be a coincidence or not but the day prior to this Encoder failing I replaced both my front hubs with MOOGs. Also other ongoing issues would be a P1682 code which when it trips it turns my 4x4 maintenance light on and turns my TC off. And lastly the Encoder always seems to fail in the cold New England weather.

Any input from anyone else who has had the same or similar issue would be greatly appreciated. I am beyond frustrated and I cannot seem to trace this issue and I am tired of throwing money at the same part over and over again. I will be testing the motor off of the transfer case tomorrow 12/8/18 and if indeed the motor is completely bad again I have another one lined up for $40 that has been tested and proved to be working.
Reply With Quote Quick reply to this message
Sponsored Links
Old 02-16-2019, 12:59 PM
Luismoreno107 Luismoreno107 is offline
Junior Member
2003 Chevy TrailBlazer LT
Dark Green Metallic 4.2L I6 4X4
Join Date: Oct 2017
Location: Greenlawn NY
Posts: 3
Have identified the short? I’m currently having the same issue not sure if just a bad motor or there’s something else at play
Reply With Quote Quick reply to this message
Old 05-09-2019, 02:39 PM
alarm15613 alarm15613 is offline
Junior Member
2008 Chevy TrailBlazer LS
Bordeaux Red Metallic 4.2L I6 4X4
Join Date: May 2010
Location: Pittsburgh, PA
Posts: 9
4X4 not working

Hello All,
I have a similar problem with my 4WD not working. Crazy thing is I parked the truck in my garage one day and didn't drive it for a couple days. When I got back in and started it the following lights came on:
Service Drivetrain
Check Engine
ABS light
None of which were on when it was parked.
I have replaced the dash switch, both front and rear actuators and encoder, and I popped a working TCCM module in place of my original. Nothing fixed the problem. I can hear the encoder motor under the driver's seat when I attempt to put it in 4 wheel but I hear nothing from the front actuator. The front was a Dorman. I don't remember the brand of the rear actuator/encoder but it seems to be working. Has anyone heard of the Dorman front actuator not working? I have had many troubles with this truck and I'm fed up with it. Already had to replace ignition switch, blower resistor pak (twice), steering wheel position sensor, and the exhaust manifold cracked at 40,000 miles. No more GM anything for me.
Thanks in advance for any help!
Reply With Quote Quick reply to this message
Old 05-09-2019, 07:14 PM
EnvoyBoy2004's Avatar
EnvoyBoy2004 EnvoyBoy2004 is offline
New Member
2004 GMC Envoy SLT
Graphite Metallic 4.2L I6 4X4
Join Date: Sep 2014
Location: NY
Posts: 2,084
Dorman electrical products are not known to be reliable. If your disconnect actuator is not operating and you have changed TCCMs (and assuming that the Dorman part is OK), there must be a wiring issue at play.
Reply With Quote Quick reply to this message
Old 05-10-2019, 10:59 AM
Irishrockdoc's Avatar
Irishrockdoc Irishrockdoc is offline
Junior Member
2006 Chevy TrailBlazer LT
Two Tone; Blue over Grey 4.2L I6 4X4
Join Date: Apr 2019
Location: Just outside of Philadelphia, PA
Posts: 8
Re Throwing an idea to look for with the electrical motor burn out

Hello all,

I am new to these forums, but not new to GM's SUV line and not new to turning wrenches on a lot of makes and models of vehicles, personal and commercial. I came to the forum today for a separate transmission issue, but came across this thread. Here is a thought to at least look at, just to rule it out or find any issues with it:

On a Ford Bronco II that I owned at one point, the four wheel drive got stuck on and I could not get it disengaged. I was told by my neighbor of the time that the issue was a vacuum switch on the transfer case. After changing that out, the four wheel drive instantly disengaged and the truck ran fine.

Since motor after motor keeps burning out, then there is a separate mechanical problem and not the electrical actuator motor. At least look in to the vacuum switch on the transfer case, as it is, at minimum, suspect.

Good luck!
Reply With Quote Quick reply to this message
Old 05-10-2019, 06:39 PM
flyboy2610's Avatar
flyboy2610 flyboy2610 is offline
New Member
2004 Chevy TrailBlazer LS EXT
Summit White 4.2L I6 4X4
Join Date: Feb 2019
Location: Lincoln, Ne.
Posts: 70
I don't have anything to add that may aid in diagnosing and fixing this issue (other than don't use Dorman electrical parts), but I have always felt that A4WD is a bad idea! The constant switching in and out of 4WD is going to cause a lot of wear on those parts. If you need 4WD, select 4HI or 4LO (depending on conditions) and then stay there until conditions permit switching back to 2WD.
Just my humble opinion, and you make take it for what it's worth.
Reply With Quote Quick reply to this message
Old 05-10-2019, 06:58 PM
EnvoyBoy2004's Avatar
EnvoyBoy2004 EnvoyBoy2004 is offline
New Member
2004 GMC Envoy SLT
Graphite Metallic 4.2L I6 4X4
Join Date: Sep 2014
Location: NY
Posts: 2,084
Irishrockdoc - just to let you know there is no vacuum involved for the transfer case on this platform.

I agree if there are multiple failures of the disconnect actuator, there maybe a mechanical problem with the disconnect itself.
Reply With Quote Quick reply to this message
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum forums, you must first register.

Please enter your desired user name, your email address and other required details in the form below.
(Only letters, numbers, dashes and underscores are permitted for user names)
The user name that you choose is permanent and can never be changed.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

» Sponsors

Advertising Info

All times are GMT -4. The time now is 04:08 AM.

Chevy TrailBlazer and GMC Envoy Enthusiasts - Copyright 2004 - 2009 All Rights Reserved.
All trademarks referenced herein are property of their respective owners.
RSS Feed