Liftgate Problems - the dealer says....

Denali n DOO

Original poster
Member
May 22, 2012
5,596
Well hello to you all, I have come from the other side and see some familiar user names here, glad I found you guys. okay so I've had a few issues lately with the Liftgate electrics. I first heard a clicking in the lock mechanism whenever the liftgate is open, had a blown passanger side license plate bulb, rear wiper not working, key fob acting strange as well. So I change the plate bulb since that was easy to do. I put the new bulb in and it didnt work as first nor did the driver side one. when I closed the liftgate i noticed they both came on briefly and then went out again. I read lots about the issues others have and some sound the same as mine. I gave up (to easily of course) and took it to the dealer due to my lack of mechanical skills and tools. The dealer says I need a new LCM mine is fried and a new latch because its rusty and the module can't read it open or closed. I near fell over when it was $123 to diagnose and $761 to repair. I went back to show them that the license plate lights have something to do with it but they say no and the fix they suggested may not fix the license plate lights. here's the weird stuff I noticed at the dealer, with liftgate open the clicking starts, if I pull ds license bulb clicking gets a bit quieter, after pull the ps license bulb the clicking stops. If there are no license plate bulbs in at all the key fob doesn't work either. I put the bulbs back in and clicking comes back, if I turn on the parking lights the clicking stops but no license plate lights are on. I also noticed that the license plate lights would flicker very dim with each click of the lock mechanism. I left the bulbs out, closed the liftgate and went to drive away but the dic said rear liftgate was open but it wasn't. I put the two license plate bulbs back in and the dic display went normal again. do you think these issues are related or seperate. any help is appeciated.:smile:
 

AtlWrk

Member
Dec 6, 2011
674
There are two possibilities I can see for an erratic LGM module AND license plate bulbs:

1) Where the wire harness passes from the lift gate to the roof/body. The wires have been known to chaffe inside that flexible rubber boot causing all sorts of odd behavior. Pull the boot at each end and inspect each wire thoroughly.

2) The lift gate module and the license plates share a common ground (G401, inside the rear-most body pillar). A flakey connection here could be causing the symptoms.
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
AtlWrk said:
There are two possibilities I can see for an erratic LGM module AND license plate bulbs:

1) Where the wire harness passes from the lift gate to the roof/body. The wires have been known to chaffe inside that flexible rubber boot causing all sorts of odd behavior. Pull the boot at each end and inspect each wire thoroughly.

2) The lift gate module and the license plates share a common ground (G401, inside the rear-most body pillar). A flakey connection here could be causing the symptoms.

I did pull the boot and look for broken wires and it all looked okay, I will pull it out again to see if I can see the wires within the boot for chaffing. any idea how I get to that ground G401, left side or right? Might anyone have a diagram of this?

Thanks.
 

AtlWrk

Member
Dec 6, 2011
674
Denali n DOO said:
I did pull the boot and look for broken wires and it all looked okay, I will pull it out again to see if I can see the wires within the boot for chaffing. any idea how I get to that ground G401, left side or right? Might anyone have a diagram of this?

Thanks.

It's under the trim of the rear-most pillar on the driver's side, just above the bump stop for the lift gate (at least on my trailblazer; I can actually see it through the vent slots in the trim. not sure about the Envoy). After seeing the pristine condition mine was in it seems an unlikely source of the problem.

Based on your symptoms my theory is that there is a break in the ground wire in your lift gate:
The license plate bulbs and LGM tie their grounds together in the lift gate then pass through the boot, through a connector, into the body and ground at G401. If there is a break between where they tie together and G401 they both lose their ground. Because they are still connected to each other the bulbs provide a very weak ground for the LGM (why you see them flickering) and all activity stops when the bulbs are pulled out. Again, a theory...

How handy are you with a multimeter? It is possible that there's a break in the conductor without breaking through the insulation.
 

Sparky

Member
Dec 4, 2011
12,927
AtlWrk said:
It is probable that there's a break in the conductor without breaking through the insulation.

Fixed because that is usually how it works. The wire strands inside the insulation break, while the pliable insulation stays intact, so at first glance they all look OK.
 
Feb 24, 2012
133
I resolved all of the issues in the tailgate of my suburban (yukon) by adding a new ground wire across the hinge, and adding a ground wire from inside the gate directly to the rear wiper motor. Before that I had all kinds of strange issues, sometimes the locks didn't work right, and sometimes the wiper motor would stop in weird places, or just sit in one spot and click (and keep clicking, even after the truck was shut off, draining the battery). I couldn't find any problems electrically, but everything started working right after I added my own ground wire. I used a 14 gauge wire, put a ring terminal on one end which went under the main body-to-hinge bolt, fed the wire through the existing wire boot into the tailgate and then put a ring terminal on the other end for the hinge-to-tailgate bolt. I think that was enough to resolve my problem, but then I added another ground from one of the latch bolts directly to the wiper motor.
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
I am going to look in that rubber boot today for a bad ground wire. I see there is also a single flat black wire near the passanger side hinge that goes from body to liftgate, does anyone know what that wire is for?
 

TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,178
Brighton, CO
Isnt that one for the rear wiper squirters....

I would suggest start with a ground wire, running to a hard connection point on both the body of the truck, and one for the hatch. Its a simple, and fairly cheap thing to do.

A thing to consider is using a jump wire as a test... Found a good ground on the body somewhere, and bolt the temp wire to it, or even use a gator clip. Then remove the inside panel on your hatch, and using a gator clip, or a bolt, bolt down the temp ground wire again to the hatch (make sure both ends are bare metal, must have a good connection). Close the hatch, test your license plate lights, locking, unlocking, wiper operations. If it works, then you have narrowed it down, and have a path of repair.
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
TollKeeper said:
Isnt that one for the rear wiper squirters....

I would suggest start with a ground wire, running to a hard connection point on both the body of the truck, and one for the hatch. Its a simple, and fairly cheap thing to do.

A thing to consider is using a jump wire as a test... Found a good ground on the body somewhere, and bolt the temp wire to it, or even use a gator clip. Then remove the inside panel on your hatch, and using a gator clip, or a bolt, bolt down the temp ground wire again to the hatch (make sure both ends are bare metal, must have a good connection). Close the hatch, test your license plate lights, locking, unlocking, wiper operations. If it works, then you have narrowed it down, and have a path of repair.

I pulled the panels off today and looked around a bit. I'm gonna try your sugestion tomorrow. I noticed the module looks like it opens so I'll look in there too.
 

91RS

Member
Dec 4, 2011
105
Take a look at the wires in the pass through for breaking and check the connector for melted terminals (disconnect it so you can see the terminals). I've seen the terminals on the connector melted way more than I've seen the wires actually broken.
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
91RS said:
Take a look at the wires in the pass through for breaking and check the connector for melted terminals (disconnect it so you can see the terminals). I've seen the terminals on the connector melted way more than I've seen the wires actually broken.

So disconnect the plug at the module and look there for melted terminals. I'm gonna buy a multimeter today and hopefully figure out how to use it. I guess to test each wire they need to be unplugged at both ends?
 

91RS

Member
Dec 4, 2011
105
No, disconnect the connector for the wires that go from the liftgate to the body. Pull out the rubber pass through and check the wires inside for being broken where they bend when the liftgate gets opened and closed and then check the connector (will be on the body side, you'll have to pull it out of the hole in the body) for melted terminals. Make sure you get the rubber pass through back on the plastic plug on either end properly or you'll have a water leak (the plug releases from the body, but usually the rubber comes off of it when removing it).
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
91RS said:
No, disconnect the connector for the wires that go from the liftgate to the body. Pull out the rubber pass through and check the wires inside for being broken where they bend when the liftgate gets opened and closed and then check the connector (will be on the body side, you'll have to pull it out of the hole in the body) for melted terminals. Make sure you get the rubber pass through back on the plastic plug on either end properly or you'll have a water leak (the plug releases from the body, but usually the rubber comes off of it when removing it).

I had that rubber boot off earlier this week and pulled the plug from the body disconnected and reconnected it. Going to friends today to investigate some more. He has a TB, too bad I couln't swap modules and try his. I did notice #15 fuse under rear seat seamed loose, rear wiper I think and it not working either. We'll see how my troubleshooting goes. Thanks for the info!
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
okay I got it all apart. The connector was in the tailgate side, is there another connector in the body side, i didnt see one and I didnt tug to hard, i can't even see the wires within the boot theres no room to pull them through the boot and look at them. Do I check for continuity from the connector to to module? This is the plug end at the module?

View attachment 21304

Do I then ckeck for continuity from the connector to the plug at the rear seat fuse panel?

Am I looking for melted terminals in this connector? Check continuity through the connector?

View attachment 21305

The latch mechanism seems a little gummed up can I spray like a wd 40 or something else to loosen up or just leave it?

View attachment 21306

This is the black wire from liftgate to body near passanger side hinge, maybe third brake light or what else is it?

View attachment 21307

The common ground at the rear pillar driverside looks nice and clean. Do I check continuity from this point to the connector at the liftgate?
 

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Denali n DOO

Original poster
Member
May 22, 2012
5,596
That was a PITA to get the rubber boot up the wires to look around. I found a broken BLACK wire and a frayed ORANGE wire. Right on :thumbsup: !
View attachment 21308


So I guess the DEALER WAS WRONG :raspberry: saying it needs a new Latch Mechanism and a new Liftfate Control Module both quoted at $761.00!! Now I'm going back to the Dealer for a refund for the $123.00 wrong diagnosis!!! That's $884.00 back in my pocket:biggrin:. I can hardly wait for that conversation on Monday...

Now to make the repair.

Thanks guys!!!
 

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The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
Denali n DOO said:
That was a PITA to get the rubber boot up the wires to look around. I found a broken BLACK wire and a frayed ORANGE wire.
AtlWrk called it in post #2! :wootwoot:
So I guess the DEALER WAS WRONG
In other shocking news, the sun will rise in the East tomorrow morning. :wink:

Seriously, what kind of dealer's mechanic WOULDN'T know in an instant that the most likely root cause was broken/flexed wires in the boot. Wonder how many other owners they quoted that diagnosis, then just fixed the wires? :hissyfit:
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
the roadie said:
AtlWrk called it in post #2! :wootwoot:In other shocking news, the sun will rise in the East tomorrow morning. :wink:

Seriously, what kind of dealer's mechanic WOULDN'T know in an instant that the most likely root cause was broken/flexed wires in the boot. Wonder how many other owners they quoted that diagnosis, then just fixed the wires? :hissyfit:

No kidding Roadie, I am far from being a mechanic and thanks to you guys was able to fix the problem without even having to use my NEW multimeter, but I'll have it for the next time. I pulled the black wire out of the boot cut it clean so no bare strands that may rip the boot going back through, squeezed the boot together. I put 2" of the black wire into a jar of vaseline and then slid it easily through the boot to the side for the repair. I soldered the black wire together and used a shrink wrap tube to seal it. The orange wire (Liftgate Module Positive) had no broken wire strands so I just wrapped it in electrical tape, installed the rubber boot back in place and it's done. All affected problems, the lock clicking non stop, the license plate lights out, key fob not working all the time and the rear wiper not working all returned to normal.

View attachment 21315

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View attachment 21317

Thanks again!
 

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Short Bus

Member
Dec 2, 2011
1,906
Denali n DOO said:
Now I'm going back to the Dealer for a refund for the $123.00 wrong diagnosis!!! That's $884.00 back in my pocket:biggrin:. I can hardly wait for that conversation on Monday...

Good luck with that, dealers don't like to give money back or admit to being wrong. Some times it works better to have a conversation with the first salesman you see on the showroom floor (a little loud, but not to rude) after they say no.

Keep us posted on how it goes.
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
Short Bus said:
Good luck with that, dealers don't like to give money back or admit to being wrong. Some times it works better to have a conversation with the first salesman you see on the showroom floor (a little loud, but not to rude) after they say no.

Keep us posted on how it goes.

I usually have success without yelling and swearing, that gets you nowhere. I wont be talking to a salesman either because he has nothing to do with the repair. I'll start with service manager then the general manager and then the owner. My bet is the service manager will make it right.
 

Short Bus

Member
Dec 2, 2011
1,906
Denali n DOO said:
I usually have success without yelling and swearing, that gets you nowhere. I wont be talking to a salesman either because he has nothing to do with the repair. I'll start with service manager then the general manager and then the owner. My bet is the service manager will make it right.

No yelling or swearing will just make you look like an nut. That's why I said "a little loud, but not to rude", and yes, sometime that works when they just blow you off with other tactics.
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
You might also have success by disputing the credit card charge with your card issuer, since the dealer failed to deliver what they were paid to. Borderline fraud. Actually - outright fraud. If they dispute your disputing the charge, I'd file in small claims. I'm SICK of dealers charging for diagnostics and then getting it wrong. It's time to hold their feet to the fire for incompetence.
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
the roadie said:
You might also have success by disputing the credit card charge with your card issuer, since the dealer failed to deliver what they were paid to. Borderline fraud. Actually - outright fraud. If they dispute your disputing the charge, I'd file in small claims. I'm SICK of dealers charging for diagnostics and then getting it wrong. It's time to hold their feet to the fire for incompetence.

I won't totally burn the bridge yet! I am taking it back so they can do the slip yoke replacement under warranty. My warranty ended in December but they could never determine what the bump was until I gave them that service bulliton. I want that done for sure since they ordered the parts already and I get the bump pretty bad. Then theres the oil in the coolant issue I still need solved, currenlty monitoring reservoir frequently to see if I can see it when it starts. The new engine warranty is until Feb 2013. If it is leaking at the head gasket then I want that fixed too. I was pretty mad when the advisor said "I must have added the oil to the reservoir":hissyfit::hissyfit:. Ya okay a 1000km since the last oil change and he thinks im adding oil to the coolant reservoir, and dirty oil at that:hissyfit:. And then I gotta pay $184.00 for a rad flush:hissyfit:. This dealership marriage is going downhill really fast and I see a divorce coming. I won't blow up at this point, this game has a few more moves yet.

They will do whats right because I'm not the kind of person to walk away when I know I'm right.

It only cost $20 here to file a statement of claim and serve it myself. I sued a Snowmobile Dealership once because I got an awesome trade in value sight unseen for my old sled because I was buying a new sled. We transferred ownership of my old one to the dealership and I delivered it at a later date as per the contract. He told me he didn't want my old sled anymore and I would have to give him the cash value instead. He then took the ownership and signed my name to it and put it back in my name and told me to get it off his property. I remember I went there the day he was having an Open House at the Dealership and served him the papers. It took a while but I was successful with my claim.:thumbsup:.
 

Denali n DOO

Original poster
Member
May 22, 2012
5,596
Short Bus said:
Good luck with that, dealers don't like to give money back or admit to being wrong. Some times it works better to have a conversation with the first salesman you see on the showroom floor (a little loud, but not to rude) after they say no.

No yelling or swearing will just make you look like an nut. That's why I said "a little loud, but not to rude", and yes, sometime that works when they just blow you off with other tactics.

Keep us posted on how it goes.

So I had the Envoy in the Dealership today so they could do the Bump When Stopped output shaft replacement as per the TSB I gave them. As they promised this was done under my old warranty :wootwoot: . When I went back this afternoon to pick it up I took the invoice for the $123.00 wrong diagnosis of the liftgate and pulled the Service Manager aside to discuss it. Then I took him to the Envoy and showed him that I solved all the issues myself and everything was functioning properly. I had left the panels off so I could show him that the latch works properly, same latch and LCM, license lights work etc. He took a photo copy of the invoice and quote and is going to take it up with the mechanic. I told him I would give him pictures of when I had the boot off showing the broken wire and the repair. He took me to the cashier and I was given a refund for the $123.00. :thumbsup:.

No yelling, no swearing and I didn't look like a nut!:biggrin:
 

AtlWrk

Member
Dec 6, 2011
674
the roadie said:
AtlWrk called it in post #2!

I can't really take credit as this was something I learned right here from someone in this community :grouphug:

Denali n DOO said:
He took me to the cashier and I was given a refund for the $123.00. :thumbsup:.

No yelling, no swearing and I didn't look like a nut!:biggrin:

That's great that the dealer gave you the refund but that doesn't make up for the fact that they had two MAJOR diaganosis failures. Seriously, you had to show them the TSB for the slip yoke? Pitiful. With the oil in the coolant it is time to RUN from this dealer to a competent mechanic who is actually interested in proper diagnostics.
 

motorhead

Member
Jul 3, 2012
2
I've been chasing these same issues for months! After pulling the truck apart in the subject area I found EXACTLY what is pictured above. Things are steadily improving now... thanks for this!
 

Punk

Member
Sep 7, 2013
1
Denali n DOO said:
That was a PITA to get the rubber boot up the wires to look around. I found a broken BLACK wire and a frayed ORANGE wire. Right on :thumbsup: !
View attachment 7424


So I guess the DEALER WAS WRONG :raspberry: saying it needs a new Latch Mechanism and a new Liftfate Control Module both quoted at $761.00!! Now I'm going back to the Dealer for a refund for the $123.00 wrong diagnosis!!! That's $884.00 back in my pocket:biggrin:. I can hardly wait for that conversation on Monday...

Now to make the repair.

Thanks guys!!!


A giant thank you for everyone's input on this issue. My 2003 trailblazer had the broken black wire and two orange wires with cracked sheeths and exposed copper. A thirty minute repair with soldering gun and shrink tubing instead of a dealership headache. If it helps anyone in the future, my symptoms were: no license plate lights, no lock or unlock at the liftgate with key fob or door buttons, complete disfunction of dash lights and dashboard indicators, no rear wipers. My diagnosis was made even simpler when I noticed the license plate lights flickering as I slowly closed the liftgate.

$0.00 repair and serious points with the wifey!
 

floridarv

Member
Mar 30, 2013
59
Punk said:
$0.00 repair and serious points with the wifey!

Wifey likes it when we look like men that can fix anything. :thumbsup: :smile:
 

triz

Member
Apr 22, 2013
746
Punk said:
A giant thank you for everyone's input on this issue. My 2003 trailblazer had the broken black wire and two orange wires with cracked sheeths and exposed copper. A thirty minute repair with soldering gun and shrink tubing instead of a dealership headache. If it helps anyone in the future, my symptoms were: no license plate lights, no lock or unlock at the liftgate with key fob or door buttons, complete disfunction of dash lights and dashboard indicators, no rear wipers. My diagnosis was made even simpler when I noticed the license plate lights flickering as I slowly closed the liftgate.

$0.00 repair and serious points with the wifey!

I don't think I have the license plate issue. But my liftgate does not lock even though I hear it. The latch also would not close till I slammed it. I'll have to wait till the weather starts to cool off so I can check it.
 

Sparky

Member
Dec 4, 2011
12,927
triz said:
I don't think I have the license plate issue. But my liftgate does not lock even though I hear it. The latch also would not close till I slammed it. I'll have to wait till the weather starts to cool off so I can check it.

That just sounds like your latch mechanism is getting all seized up. Usually all it needs is cleaned out and lubricated really well. I had to do that to mine because the liftgate glass wouldn't unlock anymore.
 

Mohalapua

Member
Oct 24, 2013
1
Contacted local Chevy dealer and they suggested a remote test for $65
Diagnostic for dome lights $110
Diagnostic for rear wipers $110
Diagnostic for non locking lift gate $110
Advised service agent of what I have been reading online and he laughed and said would you like to schedule it or not.
I said I will see how far I can get without having to shell out almost $400 on diagnostic testing. He said good luck.
These posts will certainly help me!! Thank you! :smile:
 

Robert23

Member
Mar 22, 2017
2
Ohio
I had a similar problem with my tailgate my license plate lights don't work my keyless entry doesn't work tailgate does not lock itself anymore windshield wiper doesn't work or the sprayer and I lose all power when I turn my ignition off
 

Tiggerr

Member
Jun 6, 2013
1,324
Perrysburg, OH
I had a similar problem with my tailgate my license plate lights don't work my keyless entry doesn't work tailgate does not lock itself anymore windshield wiper doesn't work or the sprayer and I lose all power when I turn my ignition off

The wiring going into the liftgate at the top, in that boot, is known to have issues. Check and make sure you don't have any broken wires. Or broken insulation and something grounding out, or two wires touching each other.
 
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jsheahawk

Member
Jan 16, 2013
533
Kansas City
The wiring going into the liftgate at the top, in that boot, is known to have issues. Check and make sure you don't have any broken wires. Or broken insulation and something grounding out, or two wires touching each other.
I second this. And look really well. I doubted that this was the cause, looked cursorily, then had to eat my words when I told Roadie that he was wrong. He was so rarely wrong...
 
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