I was initially told by my service manager that all the codes were gone, after the 3rd restart they cleared except for the CEL. I actually disputed that with the service manager. Cars with this much technology there is no way this data is not saved somewhere. Someone knows how to get it if they really wanted to. Now I have been told that corp GM engineering techs have connected to my truck and were able to get data that showed exactly what happened, how I started the truck, what codes occurred etc. People say what they want to get you out of their face. Its that simple.