2002 Deville computer issue??

2002 Deville Base

1. Battery went dead due to light being on
2. Removed battery and charged. reinstalled. Shows proper voltage
3. Car started up and runs fine.
4. No radio. Getting power. Fuses ok. No station display or sound.
5. Security, traction, air bag, and battery light on dash all stay on.
6. Get coolant warning , oil change warning, ect. Checked and no problems with levels etc.
7. Key fob stopped working. Changed battery. still not working.
8. Everything else seems to work.

Next day battery was dead again. Checked for parasite draw and pulling fuse for radio. Recharged battery and it stayed charged and started right up.

Only current code is IPC U1000 which I assume is due to radio not working.

Any help in getting radio working, lights off, and fob working?