You probably just need the code cleared if you did it all right. Your post doesn't say what year it is, but, if its a little older, you can sometimes clear the code by unhooking the battery cable for a couple of minutes. If it's newer, you'll have to get a scanner and hook it up to clear the code. Removing the battery cable on a newer one can screw up your security codes etc. and you'll end up going to a shop anyway.