I saw your post on the facebook group and have been researching. I know the below is a service bulletin for 2023 model year but wouldn't hurt to check and make sure all your connectors are seated correctly on your 2021 model XT4. Hopefully this helps solve your issue. If not, at least it helps with locating BCM in your XT4.

N222390510 Chevrolet Body Interior Technical Service Bulletin

N222390510 Chevrolet Body Interior Technical Service Bulletin

www.tsbsearch.com

 

Have a CPO 2021 XT4 Sport AWD with 60k miles, love the car, but have experienced some electrical “gremlins” already. About a week ago i got in the car and the infotainment screen was black and no sound (radio, or seatbelt, or turn signal) then it appeared to fix itself because the next time i started it that day it was fine and the problem never resurfaced. Then The other day my front windows would not roll down (with either window switch on each door) and then when I parked the car and tried to get out it kept locking the doors everytime I would hit the unlock button, now that issue fixed itself the next day when i started it up and never returned. Now tonight as I was driving down the road my driver seat just moved back to the “exit” position and is now stuck there, memory seats wont work either.
To preface, ignition off voltage levels are normal, CCA are normal levels, and ignition on levels are normal while under a load as well.
Has anyone else experienced these issues?
i read a post on an SRX Forum of a guy who had the exact same problems and it was a hose leaking into his BCM,not familiar enough with either vehicle to know the location of those hoses and BCMs

This is certainly not what we like to hear, BradSalluom95. Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with your 2021 Cadillac XT4's electric components not working properly. To do so, please send an email to socialmedia@gm.com with ATTN: BradSalluom95/Cadillac Forums in the subject line.

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