If you were still having this problem I was going to ask if the tune was a SCT handheld or before it's time it was a push in chip to the backside of the ECM... I had a chip from SHM that from day 1 wouldn't let me start my truck so I did what I thought would work and ruined a $225 chip... SHM told me because I messed with it, it was my $225 paperweight... I then bought a Superchips and it also had issues but when I installed it I used duct tape to hold it from coming loose... As soon as you described it I knew it was the chip... Sorry I couldn't help you from getting it towed to the dealer but this website is older and I don't come on but a few times a year...

