The bolt doesn't look like its worn or has damaged threads. It just won't stay tight.
Since you all have given suggestions about the bolt, and it seems to look ok, it still leaves the question
as to why it loosens up so quickly.
What would happen if we were to unscrew that bolt and check the back of the orange section to make sure that
all of the wiring is ok? If we disconnected it from the BCM, would we then have to re-program it when we connected
it back?
Thank you again to those who are giving us suggestions. It is deeply appreciated.

 

No you wouldn’t have to reprogram the BCM

 

Probably smart to pull the negative wire off the battery before you pull the plug. The battery is in the back next to the spare tire.

 

Maybe a bit of blue Loctite?

 

A look under the orange plug, we see the metal threaded nut, which might be loose.

 

Super glue

 

No that’s not a good idea in case you need to remove the plug.

 

We are pretty sure that the problem is the Instrument Fuse Panel AND Wire Harness. Today the car shut off as we were driving
and that scared the beejeebers out of me. I hate to take it to another dealer because I don't know of any of them that won't screw
you til your blue and not put a smile on your face. Does anyone happen to know if there is a mechanic in particular to take the car
too, and any idea as to the cost to replace the Instrument Fuse Panel AND the Wire Harness?
Thanks to all of you that have responded to me so far. I truly appreciate your help.

 

BCM

https://www.gmpartsgiant.com/oem-che...ol_module.html

 

If you replace the BCM you will have to go to a dealer or somebody with the correct equipment to program it.
How do you think the harness and BCM got damaged; it takes physical abuse to break a harness and real stupidity to break a BCM.

There is no such thing as "instrument fuse panel" it is called BCM, BodyControlModule. It is both a computer and a fuse block.
Has the ignition switch recall been done?
Did you reconnect the plugs?