Dangling Yellow Wire After Dealer Service

[AshleyM]

I picked up my 2023 GMC Yukon Denali Ultimate from the dealer (Thompson GMC - Raleigh, NC) after they performed the Trailer Brake Control Switch recall, and noticed a dangling yellow wire in the driver footwell.

For safety, I've taped the end with electrical tape until I figure out what it's related to.

Does anyone know where it needs to be connected?

 

[WalleyeMikeIII]

Hey Ashley, as much as it is a bummer to have to return, I would go back to the dealer and ask if this is supposed to be disconnected now, or if they need to repair it. Unfortunately, I am not sure what exactly that wire is for...but...

Check this thread (esp post #3), it looks suspiciously like the door sill plate accessory wiring harness, do you have the illuminated sill plates, and are they still working?

2021 Tahoe Illuminated door sills

Has anyone installed the illuminated door sills on their 2021 Tahoe yet, or had them installed? No instructions were included and none on the GM parts site like most of the parts have listed. Just need to know what pin in the BCM harness I need to tap into, a pic would be great. I have a...

www.tahoeyukonforum.com

 

[AshleyM]

That's an excellent tip - thank you!!

Going to confirm tonight that the rear door sills aren't illuminating and then take it from there.

 

[WalleyeMikeIII]

That's an excellent tip - thank you!!

Going to confirm tonight that the rear door sills aren't illuminating and then take it from there.

You can put a hat or glove or piece of paper over the sensor in the dash, to fake it out that it is dark..don't have to wait until tonight.

 

[AshleyM]

I found instructions for my 2023 Yukon that say the yellow wire needs to be connected to Body Control Module X7 pin 24 "Rear Footwell Accent Lighting Control". I did that and put a magazine over the light sensor on the dash, but the rear door sills didn't turn on when the rear doors were open.

I waited until it was dark and tried again, but they still didn't turn on, and I also noticed that the front ones weren't working either. So now I think I'll need to take all the door sills and panels off so I can trace the wires to see where or if they're connected.

My hunch is that the wiring for my door sills was affected when they did the recall for the trailer brake control switch.

 

[WalleyeMikeIII]

Well, if that thing is disconnected, they def will not work. If they were working before the recall; I’d head to the dealer and make them square it up. Note also that thread I linked above contains the PDF of the illuminated door sill install instructions; later in the thread.

Might also double check the purple wire to make sure it is still seated in it's connecter as well. If they inadvertently pulled on those wires, the connection there could be suspect as well. The ground is over on the right side passenger footwell, under a bolt. Can't imagine ground is broken.