Was going to return to stock tune before service appointment and had the same thing happen to mine. So I will be calling as soon as I get home.

Good day all. I have the C7 in the subject and am able to apply the Diablo tune modified with AFM set to off. However I had to set the Trinity vehicle options to Manual Transmission since it would give an error when trying to backup the TCM. New to the whole tuning thing and look forward to some ...