Rear latch assembly not functioning on Lift Gate - 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 General Tech Q&A > General

General If it doesn't fit in any other forum

TrailVoy.com is the premier GMC Envoy Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools
  #1  
Old 10-12-2009, 11:50 AM
hoppa hoppa is offline
Junior Member
 
2005 Chevy TrailBlazer LS
Pewter Metallic 4.2L I6 4X4
Join Date: Oct 2009
Location: Milwaukee, WI
Posts: 15
Rear latch assembly not functioning on Lift Gate

Alright, here is my first tech question for you all. I just bought my 05 trailblazer two days ago and I am having an issue with the rear lift gate. It does not function properly.

When I press the lock button on the keyfob, I can hear a faint click when I am outside of the vehicle's rear, near the handle for the lift gate with the . However, the actuator doesn't actually lock the hatch. I can go to open the hatch and it opens like it is unlocked (even though it should be locked) and then my alarm goes off. So basically my rear lift gate is always unlocked and anyone can get in it at any time!

Also, when I press the button to open the rear glass, nothing happens.

Any ideas how to fix those two issues? Is a complete assembly required? Maybe just an actuator? WD-40?

I've seen a few other posts on the topic, but I've never seen any info about the rear window button not working as well as the locking mechanism for the lift gate latch. I'm guessing someone is going to mention the fuses but they are all good.

Thanks!
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 10-22-2009, 12:26 PM
hoppa hoppa is offline
Junior Member
 
2005 Chevy TrailBlazer LS
Pewter Metallic 4.2L I6 4X4
Join Date: Oct 2009
Location: Milwaukee, WI
Posts: 15
Ok, I know you are all sick and tired of this question because it has been solved in other threads, but I think mine is quite different. I checked the wires leading up thru the lift gate to the roof and they are all good from the looks of things. None of the wires seem to have any wear on them.

When I have the lift gate closed and hit the lock button, I can hear the control module make a noise, but the lock doesn't function properly. I sprayed down the area with WD-40 because I thought it might have been locked up due to corrosion because the supports that the lock grabs on it (don't know the correct part name for it, sorry) has quite a bit of rust on it.

However, that didn't fix the problem. There are two harnesses going into the lock. What do each of them do and which one should I test to see if the control module is sending a signal to the lock?

If it indeed is the lock that is bad, do I need to take it into a dealership and have it reprogrammed? Or is that just for people that replaced their control module?

any help is appreciated!
Reply With Quote Quick reply to this message
  #3  
Old 10-22-2009, 12:36 PM
the roadie's Avatar
the roadie the roadie is offline
No longer with us
 
2004 GMC Envoy SLT "Roadiemobile"
Extreme Offroad Pewter 4.2L I6 4X4
Join Date: Apr 2005
Posts: 26,181
Here's the schematics.
Attached Images
  
Reply With Quote Quick reply to this message
  #4  
Old 11-23-2009, 05:54 AM
hoppa hoppa is offline
Junior Member
 
2005 Chevy TrailBlazer LS
Pewter Metallic 4.2L I6 4X4
Join Date: Oct 2009
Location: Milwaukee, WI
Posts: 15
So I did some more digging around in the lift gate. I took the lock completely out:



I made sure all the movable parts on it could indeed move and weren't "frozen" from corrosion. I definitely thought it would be a corrosion problem at first because look at my posts:



However, since the lock seemed fine, I moved on to the wiring:

I'm not the best at reading schematics but I figured a trusty meter would help me make sure I was getting power to the lock. Sure enough, I was:



I was getting around 8 volts to the gray wire leading into the lock on the two-wire harness when I hit the lock button on the keyfob. I wasn't able to get any readings off the three wire harness leading into the lock...and from what I can tell, those wires are just for the "ajar" and "open" sensor so I didn't really need to worry about those.

Even though I had already checked the wires leading thru the boot near the top of the liftgate glass, I decided to take another peak. Lo and behold, I find a crack on the plastic insulation on the fat orange (HOT!) wire and the fat black ground wire. The Orange wire still was hot surprisingly. I figure something like that, if it actually would have ground out, would have popped a fuse or something...but nope, it was still hot!

I could tell something was up right when I pulled the lower portion of the boot off because it had a bad electrical tape job over some wires. Definitely not from the factory:




So I pulled back the electrical tape and there it was! Hot orange wire right next to the ground wire:




So I cut the wires and tossed in butt connectors and did a good job with the electrical tape and sealed everything back up.

Now my question to you is what do you think my problem is since I have 8volts going to the lock but the lock isn't functioning. It was sending the 8 volts even before I found the wiring issue, so that makes things a bit strange. Do you think the wires shorted something out in the LGM causing it to malfunction? I don't think that is the case because it is properly sending out the 8volts to the lock thru that gray wire...the lock just doesn't do anything.

I'm thinking it's the lock but let me know what you think now that I have all the information...
Reply With Quote Quick reply to this message
  #5  
Old 01-29-2010, 10:53 PM
Rodgers's Avatar
Rodgers Rodgers is offline
Junior Member
 
Envoy GMC Envoy SLT
Indigo Blue Metallic 4.2L I6 4X4
Join Date: Sep 2009
Location: Vallejo, CA
Posts: 11
I am having problems with my lift gate latch also. I have power to wiper, defroster and the fluid all works. I am unable to unlock with the fob or the power door. (no key lock on the hatch) I was able to crawl back there and I can physically unlock the window and the door. There appears to be a missing piece, there is a red piece that looks like it holds an arm of some sort but I do not know what. (I am only looking through the small hole. I can try to take it apart tomorrow to see better but if I need a part I would like to get it in advance. There is no rust or corrosion of any kind and I did give it a good WD40 shower.

Any help would be much appreciated.
Reply With Quote Quick reply to this message
  #6  
Old 01-30-2010, 12:21 AM
the roadie's Avatar
the roadie the roadie is offline
No longer with us
 
2004 GMC Envoy SLT "Roadiemobile"
Extreme Offroad Pewter 4.2L I6 4X4
Join Date: Apr 2005
Posts: 26,181
Check the exploded parts views on www.compnine.com
Reply With Quote Quick reply to this message
  #7  
Old 01-30-2010, 12:59 AM
jacob789456's Avatar
jacob789456 jacob789456 is offline
Senior Member
 
2002 Chevy TrailBlazer LTZ
Red Jewell/Pewter 2-tone 4.2L I6 4X4
Join Date: Jul 2009
Location: City of San Diego, CA
Posts: 912
A bad liftgate control module (LCM) maybe? It is not uncommon for these modules to go bad and start doing weird things. I would check that out and see if it is getting sufficient power. I think it is the orange wire in the wire bundle, but I would check other threads first before poking into some hot wires with your voltometer.
__________________
02' Trailblazer LTZ 4x4 with 3.73's & G80
Reply With Quote Quick reply to this message
  #8  
Old 06-13-2010, 03:56 PM
blackroush blackroush is offline
Junior Member
 
2006 Chevy TrailBlazer LT
Imperial Blue Metallic 4.2L I6 4X4
Join Date: Jan 2010
Location: Detroit
Posts: 2
Lift Gate Control Module

Did you find out what was causing it? I am having the same issue on my 06 TB. I hear the mechanism, but it don't lock. I am thinking a bad actuator that cannot fully activate...

Check this out...
http://townhall-talk.edmunds.com/direct/view/.f107cf5
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




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 05:52 PM.


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