When attempting to install an H&S Mini Maxx on your 07-10 Duramax and you get code 312, go to show settings & hold down bottom left key 10 seconds then a screen will pop up. Enter unlock code 0468.

Then select reset unit then go directly to install download, do NOT re select truck and year.

Error code 316:

This code means that the tuner isn't communication with my ECM and there must be a tune on the truck or has been a tune on it in the past. Your truck will first need flashed back to stock at your local dealer before before the Mini Maxx will install.