99% of newer cars can't have the codes pulled without a scan tool. You're best off finding a friend who has a scan tool if you're hurting for cash, but if nobody has a scan tool, you're just going to have to get it fixed at a shop or pay the fee to get the codes pulled. Most shops charge about 50-75 bucks to pull codes and reset them.
Oh, another cheap alternative is to see if the Autozone (or whatever) has one of the scanners made for one vehicle make. Usually they have all the GM and Ford vehicles, but it's hard to say if they'll have a Mazda code checker.
Good luck...you're probably just going to have to bite the bullet and take it to a shop.