OK I am new at this tuning thing and I have done a few little things and trying to expand a little bit. I was trying to read an 0411 ECM and all I could get was Detect Protocol Failed. So I thought something was wrong with the program so I uninstalled it and turned around and reinstalled it from HP Tuners website. I read a couple of cars and thought it was fixed. No it is still doing the same thing. I tried reading my 2002 Tahoe and same message. I tried reading my daughters 2003 Tahoe and same message. On both Tahoes I removed radio, onstar, navigation fuses same problem. I am using the MPVI2. I also was able to read without any problems a 2007 Yukon. Any help from any and everyone is greatly appreciated. Thanks