What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[gooffeyguy]

If you have the factory tilt sensor, and it's still mounted on the lower airduct, there is a TSB about relocating it..

View attachment 435006

Mine used to go off all the time, I just removed it instead.
Opening it, there is a metal dome on a circuit board about the size of a half dollar with liquid inside.

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How was it mounted, sticky tape?

 

[mikez71]

Update...

Went out and started yukon and the "Rear door unsecured" or whatever message was on the DIC. I opened the liftgate with the button on the overhead and went back to make sure the Husky mat wasn't blocking anything then closed it with the button on the liftgate. Message went away. I then went back and opened the glass and the same message displayed on the DIC. Closed glass and message went away.

So, is the sensor built into the latch? If so, how do I tell which latch, the liftgate or glass, may be going bad? Would the Tech2 help with this in any way?

They have seperate sensors. Liftgate Open/Ajar or Liftglass Ajar. I would have assumed the Tech2 would show it, but can't find it in the Tech 2 Paths..

 

[mikez71]

How was it mounted, sticky tape?

Yep, and it was about 3/16" thick with a cutout for some bumps on the bottom side that would have allowed it to mount on a tab.

 

[mikez71]

Found it. liftglass under liftgate module, liftgate under bcm rear body.

 

[CMoore711]

Been hearing an inconsistent klank up front for a few days and the front end just feeling a little “loose”.

Found out my front passenger side sway bar end link decided to end our relationship without telling me…

 

[gooffeyguy]

If you have the factory tilt sensor, and it's still mounted on the lower airduct, there is a TSB about relocating it..

View attachment 435006

Mine used to go off all the time, I just removed it instead.
Opening it, there is a metal dome on a circuit board about the size of a half dollar with liquid inside.

View attachment 435007

I broke out the Tech2 and figured I'd look at the Theft Data info to see what triggered it. There was no trigger history, lol

 

[gooffeyguy]

View attachment 434938

Had the tech2 hooked up a bit ago. Here's my fuel pump modual data screen



Also while in there looking around I noticed a screen where you can get a whole lot of misfire data.

Under ECM, Data Display, Misfire Data

 

[Doubeleive]

I broke out the Tech2 and figured I'd look at the Theft Data info to see what triggered it. There was no trigger history, lol

View attachment 435030

the only thing that really set's off a factory alarm on the gmt800/900 is if a door is opened while it is armed, so it could very well be the rear hatch sensor. not sure how the rear actuator is configured as far that goes.
@mikez71 that's a mercury switch, it was probably added on at some point i don't think my Denali even has one factory

 

[Doubeleive]

Had the tech2 hooked up a bit ago. Here's my fuel pump modual data screen

View attachment 435031

Also while in there looking around I noticed a screen where you can get a whole lot of misfire data.

Under ECM, Data Display, Misfire Data

ya that's where you get the misfire graphic, that's seperate from just regular misfire monitoring

 

[gooffeyguy]

the only thing that really set's off a factory alarm on the gmt800/900 is if a door is opened while it is armed, so it could very well be the rear hatch sensor. not sure how the rear actuator is configured as far that goes.
@mikez71 that's a mercury switch, it was probably added on at some point i don't think my Denali even has one factory

I was hoping that theft data would tell me which sensor set the alarm off, but it shows like it never went off.

 

[Doubeleive]

I was hoping that theft data would tell me which sensor set the alarm off, but it shows like it never went off.

might be in the history codes, otherwise it probably only shows it when active

 

[mikez71]

I remember having codes for my tilt sensor when that was the culprit..
Since you got liftgate open messages, I would guess it to be the hatch or the glass..

Seems like they share the AJAR signal the more I look at it..

 

[gooffeyguy]

Well I just got home from running some errands and it hasn't done anything weird. Hope that by opening both liftgate and the glass and making sure nothing was hindering it's closing and also spraying the latch mechanism with GM multipurpose lubricant fixed the problem.

My wife said I probably picked up a ghost, lol.

Oh, and the message on the DIC says "Rear Access Open" and not Liftgate Adjar or anything like that, so just kinda vague.

 

[bobsburban]

Got a full transmission service/flush and installed the backup Cold-Case aluminum radiator in the 2500 'Burb this week. Wife noted the need for shocks as we drove to and from a gathering last night. They were next on the list anyway.

Put the 1500 up for sale. We shall see. I'd like to recoup two-thirds of what I paid for the 2500 and if not that, at least cover the cost of the new gutter guards...

 

[Doubeleive]

Well I just got home from running some errands and it hasn't done anything weird. Hope that by opening both liftgate and the glass and making sure nothing was hindering it's closing and also spraying the latch mechanism with GM multipurpose lubricant fixed the problem.

My wife said I probably picked up a ghost, lol.

Oh, and the message on the DIC says "Rear Access Open" and not Liftgate Adjar or anything like that, so just kinda vague.

you can determine which one it is saying by opening either the hatch or the glass and then go put it in drive

 

[gooffeyguy]

you can determine which one it is saying by opening either the hatch or the glass and then go put it in drive

Nope, they both say "Rear Access Open" whether it's in park or drive.

 

[Sparksalot]

Nope, they both say "Rear Access Open" whether it's in park or drive.

View attachment 435052

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That’s what mine does too.

 

[mikez71]

Yep, if you look at the diagram, the two signals are spliced together...

If it keeps happening, you could unplug one of the ajar switches to test, as the other will still work.
I would be especially careful with the wiper while disabled.

 

[gooffeyguy]

Yep, if you look at the diagram, the two signals are spliced together...

View attachment 435055

If it keeps happening, you could unplug one of the ajar switches to test, as the other will still work.
I would be especially careful with the wiper while disabled.

Is the ajar switch separate from the closure mechanism or is it in the mechanism and just has a separate wire connector?

 

[Doubeleive]

Nope, they both say "Rear Access Open" whether it's in park or drive.

View attachment 435052

View attachment 435053

wierd I thought they showed different but I think I only had the message come up twice in the last 7 years