Crazy phantom door dome light issue

[541DenaliErick]

Hey crew, this is my first post, sorry to post based an issue! I promise I will show off my personal truck soon!
So, I have a customers 2007 GMC yukon. It has a crazy issue I havent been able to fully diagnose.
The interior lights will come on at random and erratically, BUT it does seem to be related to the drivers door.
It happens no matter what the condition. It also affects anything related to the doors opening such as auto door locks (the locks will cycle locked while driving due to auto door locks), the fob will lock but the alarm will not arm (due to the VTD not arming as it senses a door open. Additionally if the issue happens after the system arms, the alarm WILL go oof as the car thinks a door opened while armed).
Whats crazy is that while driving, the DIC will not chime and alert you that "X" door is ajar, yet the dome lights will turn on and the BCM reports on live data that the reason for dome lights is DOOR AJAR.
The front two door modules are properly reporting latch open/close positions and the data pids for these will be correct even when the dome lights are on. The other door switches and tailgate/lift glass are reporting closed/open positions properly as well. Additionally, if any of these are opened in gear or while driving, the DIC will display "X" door ajar and there is a chime.
The customer reports the BCM has been replaced with no change. The BCM is a "reman" pre programmed unit. I have programmed it via SPS with the option to delete automatic door locking, so the software flash is now correct for the vehicle.
I am lost on where to dig to find the issue. Im hoping you guys have the time to share ideas on what to check as its really getting under my skin lol.
I really pride myself with my diagnostic abilities, but this one is kicking my ass so hard.
I made these quick videos to show my state of progress.

 

[Tahoe14]

@Doubeleive

 

[Doubeleive]

Hey crew, this is my first post, sorry to post based an issue! I promise I will show off my personal truck soon!
So, I have a customers 2007 GMC yukon. It has a crazy issue I havent been able to fully diagnose.
The interior lights will come on at random and erratically, BUT it does seem to be related to the drivers door.
It happens no matter what the condition. It also affects anything related to the doors opening such as auto door locks (the locks will cycle locked while driving due to auto door locks), the fob will lock but the alarm will not arm (due to the VTD not arming as it senses a door open. Additionally if the issue happens after the system arms, the alarm WILL go oof as the car thinks a door opened while armed).
Whats crazy is that while driving, the DIC will not chime and alert you that "X" door is ajar, yet the dome lights will turn on and the BCM reports on live data that the reason for dome lights is DOOR AJAR.
The front two door modules are properly reporting latch open/close positions and the data pids for these will be correct even when the dome lights are on. The other door switches and tailgate/lift glass are reporting closed/open positions properly as well. Additionally, if any of these are opened in gear or while driving, the DIC will display "X" door ajar and there is a chime.
The customer reports the BCM has been replaced with no change. The BCM is a "reman" pre programmed unit. I have programmed it via SPS with the option to delete automatic door locking, so the software flash is now correct for the vehicle.
I am lost on where to dig to find the issue. Im hoping you guys have the time to share ideas on what to check as its really getting under my skin lol.
I really pride myself with my diagnostic abilities, but this one is kicking my ass so hard.
I made these quick videos to show my state of progress.

Looks like a short somewhere when the body is shook from door closing. You can see specific door info by looking at the driver's door switch for drivers door, passenger door switch for passenger door, then go to bcm body control module, body rear end for rear hatch info, then you will also see "doors" for rear doors.

 

[Doubeleive]

I would also pull the underhood fuse box and inspect the pins for corrosion

 

[mikez71]

weird, door module disconnected?

 

[Doubeleive]

weird, door module disconnected?

drivers door unplugged yes, and the screen he is on with tech2win only shows reason:door ajar not which one, for that you have to look at other data

 

[mikez71]

Looking at the 07 diagram, the rear doors have one input for open, but separate signals for ajar.
Watching your video, the reason was DOOR OPEN, not DOOR AJAR.

It can't be your driver door if it was completely disconnected.
Perhaps opening and closing the driver door is shaking one of the rear door open switches?
Or maybe the orange wire is worn somewhere and contacting ground?

Perhaps try disconnecting the orange wire (j6-16 from BCM) as a test..

 

[Doubeleive]

Looking at the 07 diagram, the rear doors have one input for open, but separate signals for ajar.
Watching your video, the reason was DOOR OPEN, not DOOR AJAR.

It can't be your driver door if it was completely disconnected.
Perhaps opening and closing the driver door is shaking one of the rear door open switches?
Or maybe the orange wire is worn somewhere and contacting ground?

Perhaps try disconnecting the orange wire (j6-16 from BCM) as a test..

View attachment 438624

Could be a possibility but I don't think the interior lights differentiate between the two references, rear door data says ajar, lights say open for the same data

 

[mikez71]

Looks like ajar switch can be DOOR AJAR or DOOR CLOSED. And the courtesy lamp maybe DOOR OPEN or DOOR CLOSED..

That makes me think the door open switch turns on the dome lights and the ajar switch lets the BCM know which doors are open? idk

 

[541DenaliErick]

Looking at the 07 diagram, the rear doors have one input for open, but separate signals for ajar.
Watching your video, the reason was DOOR OPEN, not DOOR AJAR.

It can't be your driver door if it was completely disconnected.
Perhaps opening and closing the driver door is shaking one of the rear door open switches?
Or maybe the orange wire is worn somewhere and contacting ground?

Perhaps try disconnecting the orange wire (j6-16 from BCM) as a test..

View attachment 438624

Bingo.
It was the rear door open circuit.
Basically a dome light only circuit which both rear doors share. There is no data pid for input to the BCM but after studying the diagram I found that circuit. And immediately suspected it.
Pulled pin 16 from the pink BCM connector and boom. Dome light issues gone. Then I put the pin back in the BCM plug and unplugged the drivers side rear door. The issue went away again, proving failure somewhere in the drivers rear door.

HOWEVER...
After reconnecting the drivers rear door, the short to ground also went away and I haven't gotten it to come back!

Thanks for the replies you guys!
It's awesome to feel this much support from this community!
I will also do my part, I have a 12 Denali XL which I love very much.