Not sure which forum this should go in because not sure if it is ECM or TCM but I have an '11 5.3 truck on 35s and when you turn on cruise control it drops ~3 MPH then rises back to the desired speed and will continue to hold properly. This can be annoying because at low enough speeds it will downshift. The speedo is correct and my other speed data should be correct. Is it the factory ABS or other computer that needs a tech2 reprogram? Suggestions would be great thank you.