Car alarm going off.

[Silver09]

Yesterday I shut my trunk and the alarm started going off randomly. Today after I got into my car and started it, it went off again. I recently installed a kenwood touch screen little over a week ago and haven't had any problems (unless wires came loose?) I searched and seen other people have had similar alarm problems but I was wondering could the head unit be the problem? The service engine light has been on, but its on quite often because here in jersey the gas attendants don't seem to know how to twist the cap till it clicks so idk if that's telling me there's a problem. Figured I'd post here before I get raped at the dealership. ****ALSO this kind of problem should be covered under warranty ?