I don't know either I just went and double checked there are no stored codes in the bcm or ecu, but when I do a full system scan the ones I know are there from my own doing show up, but there scan showed old ones I know were cleared and do not show up presently, maybe i'm not looking in the right place, maybe it has a saved place somewhereYeah, never heard of that. Wonder if they still reside in the truck somewhere or were transmitted to GM?