If you don't know someone that has one, run it over to your local "Autozone" and have them do a full code scan, I've never had my CEL light come on for no reason, but I have found body module issues before that didn't come up on a basic scan. If you plan to own the E53 for any period of time, it will pay you back 10 times over in the first year of ownership - buy a Foxwell NT510 \ 510 Pro scanner, you will be very happy you did