their workers aren't allowed to, but you can borrow one with a fully refundable deposit.

they ring it up, go outside pull the code, go back in and return it.

 

You can buy one of the less expensive OBD II scanners for about $100, pretty well worth having- given that most dealers are going to hit you for at least that much just to pull a code.

I know- yeah, you can get other shops and other people to do it cheaper and even free- sometimes, but especially if you are into mods and "aftermarket" tuning stuff- you can't be too sure about driving with a CEL on unless you know what it is.