Just bought a 2006 Cobalt and there was an aftermarket remote start installed when i looked at it from the dealership. The remote start wasnt hooked up right and you could not turn the key in the ignition. So they removed it. Today when we picked up the car from the dealership we broght it home and locked it. When we went out to the car later unlocked it with the key and the alarm sounded. It started out with a few steady beeps then after a few seconds started going off. Is there anything i can do to disable this. i really dont wanna bother the dealership if it is something easy that i can do.. THANK YOU

 

Sounds like it thinks its being hotwired with the remote start disabled.
The only foolproof way to fix it is to take it to a Sound & Security shop and have them either find the problem and fix it or take the whole unit out and replace it with a new unit.

 

Take it back to the dealer and tell them to fix it right. You should have a warranty still.

 

I believe the factory alarm can only be disable by using the factory fob, by turning the ignition on with a validated key, or by adding a data module in conjuction with remote start.

This is a normal condition and can be fixed by adding either a remote starter or keyless entry module, with a data module to controls the door locks. Although these vehicles are VERY easy to work on, as you have already experienced, not everyone is capable of doing this stuff