It does sound like your car is paging you. I ran across a 479V manual, and perhaps it will help:
http://www.directedstore.com/manuals/479V.pdf
Here is the installation manual for a 791VX, which works with the 479V, as does the 591, 690, and 790. Not that this in the installation guide, and there are many options when the device is installed. Hopefully, there will be a method of resetting the unit. Here's the manual:
http://www.scribd.com/doc/21662681/791VX-Installation-Manual
Bad grounds can cause havok with a system, as can bad wiring or sensors/'switches. There are alarm installation shops that could probably help you, but it could be expensive since they have to spend the time figuring out the installation wiring, etc.
Try going over some things in the manuals first, and lastly, make sure you have a good battery in the remote, and clean it's contacts- they can become slightly oxidized over time.
Good luck, and hope this helps.