2017 Yukon - Brake / Taillights

[AndyAndy]

I've read about issues with the control module that run each light, but I'm having multiple issues at once. I thought about checking to see if the fuse blew, but figured I'd post the issue here first:

 

With brakes applied, all 3 red lights don't work.

 

Without brakes applied, left light has one single LED illuminated in the bottom left corner. Upper light inop. Right light fully operable.

 

(Picture is without brakes applied)

Edited April 12, 2022 by AndyAndy

[cs15dah]

Might be multiple problems at once.
 

First thing I’d check is to pull the codes from the modules. Not with a simple OBDII reader, but one that’ll pull codes specifically from the BCM. 
 

With the various LEDs being out, I think there’s a thread here that describes the problem and how to fix it. I think it was something to do with resoldering connections that became broken.  
 

The high mounted stop lamp ONLY comes on when brakes are applied. So you should not see them illuminate with the brakes off.