What would make the temperature gauge stop working all of a sudden?

What is your question?

I programed a new key fob earlier in the day and when I went back out to go to the store, about 4 hours later, I had no coolant temp, no cruise control and now I have a P0700 tranny error. I do think the coolant temp is the cause of the tranny error but is it a fuse, thermostat or sending unit?