I have a 2004 Cavalier 2.2 with about 80k miles on it. About 2 months ago the keyless entry stopped working randomly with no other problems. Both remotes have new batteries, but nothing works. So I have to use the key to open the doors and trunk.

The factory key will not open my driver side door, only my passenger door. (unrelated I think, but still annoying)

The factory CTD system (content theft deterent) started acting crazy. anytime I open the doors, locked or unlocked, key or no key, the horn chirps for 10 seconds and then goes to full scale alarm until I get the key in the ignition and start the car.

Then recently my service light and air bag light came on, using a scanner at an auto parts store was unable to read any codes at all.

At random times, the aftermarket radio I installed, (that has worked fine for 5 years) turns off by itself. When it does this only turning the car off and on again will allow me to turn the radio back on.

I dont know if most of these are related issues or not. Any info or clues you could give me to diagnose or fix the problems would be greatly appreciated. Money is a issue, so I prefer to avoid the dealer if at all necessary.

You need a real scanner to find out airbag codes. Any place like big o, tire kingdom, ntb, firestone, would have s proper scanner. Until then, I could only guess what's going on.

It could mean low voltage, check your battery and alternator for proper output.Also check the ground on the battery tray and the battery connections.