This started a few months ago and has gotten worse now. While driving the dash gauges will start going in all directions and alarms will start appearing which dosen't make any sense and the transmission starts shifting very hard. The dealer $110 few says he doesn't know what is wrong.
Need a little direction and a starting point for me to go on.

Sounds like a problem with the BCM, or connections to it. GM recomends applying a coating of a clear dielectric grease to the terminals of the connecters to help with what is called "terminal fretting". You can try this and see if it helps. Did the dealer say if any codes were stored? Have seen lots of problems with the BCM and connectors/terminals on the those.

If the BCM needs replaced, it will need to be "set up" using a TECH II scanner

I'm sorry that so far the diagnosis has been unsuccessful. If I can follow up with your dealership for you, please send me the last 8 digits of your VIN, the name of your dealership, and your name and contact information in a private message here on the forum.
Regards,
Sarah
GM Customer Service

Thanks for the help. The diolectric spray seems to have worked for today. So far after checking all the connections and cleaning some with the spray so far today no problems.
Will use it tomorrow for a trip of 300 miles and hope it holds.
I apprciate your help :smile: