Computer-dash info screens and drive modes. I am unable to change or check onboard dash info upon starting vehicle. Dash ds not hold settings one day to the next. Unable to get into or change settings such as trailer settings-so cant change braking effort-dangerous when hauling 20,000# trailer! Cannot put truck in tow mode or any other mode-defaults to slippery road mode. Again dangerous. Says hill start assist, hill descent assist and pre-collision assist is unavailable . This is all very potentially dangerous especially when hauling! Dealer cannot find problem. After truck is driven a while settings can be re-entered-truck has to be turned off first. Unable to load video of start up.