No communication?

It sounds like the PCM, BCM or ABS module is shorting out, but we need to do a CAN scan to see what codes are stored.

You can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

and

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Here is one for about $99.00 if you need it:

https://amzn.to/3ZixY4v

Here is how to change out the BCM in case a code comes up for it, you can get a preprogrammed unit by searching Google or Ebay. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.

The U0073 code is a generic diagnostic trouble code (DTC) that indicates a communication problem between different control modules in the vehicle. In your 2008 GMC Yukon, this code typically points to a communication issue on the Controller Area Network (CAN) bus, which is the network that allows various modules in the vehicle to communicate with each other. Here are the CAN wiring diagrams so you can see the modules involved. I would turn the ignition on and check all fuses, this guide can help:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Check out the images (below). Please let us know what happens. It still sounds like the BCM is out.