Most autopart stores (autozone/VIP/pep boys) will scan the OBD-II for trouble codes. Personally, I (rather, my dad) has an OBD-II scanner.
You can check the trouble code with this site
http://www.obd-codes.com/trouble_codes/
edit: the receptacle for the OBD-II scanner is just above the pedals, look for a black plug.