I need some suggestion

I have a 03 impala ls and my problem is that when it starts to get hot outside the message center gos crazy.It reads scurity, door ajar, battery, serves ENG. The radio locks out and I cant use my keyless entry and my A/C does not work. I can hear the Battery Protection relay going off. I swaped out the relay and thats not it. I connected a programer and there were no codes. And none of this happens at night when it cools off. I think that it might be the computer over heating, or a sensor somewhere? If you have any ideas please post them.

When I started experiencing goofy things like that (i.e. the AC not working, blinkers only working when they wanted to, etc) it turned out to be a faulty ignition switch....