I had a similar instance. I disconnected the battery to clear the light and it hasn't been back.

I was told by the dealer that it was likely caused by my hard start/long cranking issue (lack of fuel at startup).

As far as I knowany OBDBII(?) scan tool should work. If Autozone can do it, your bro's shop likely wont have any trouble.

I do know that HarborFreight sells a scan tool that will work for our cars that is like $40.00. I was going to buy it, but the more I think about it the more I realize that I wont ever use it.

For the record - if you disconnect the battery, you will lose the codes it has stored.

SQ