I had a similar thing happen this morning. The fans went to high speed, and the temp gauge went to zero.
I've also had an issue with the wipers moving to the intermittent position by themselves.
And a probably unrelated event: My hood popped open to the safety catch on the freeway! It was fully closed when I started the trip. Yikes!
Anyway, I inspected the temp sensor but decided a power reset was in order.
Problem(s) have ceased.
Methinks that some of the PCM code musta been written by Microsoft!
Now to figure out the hood issue.
2015 Silverado LT.