My 2012 Crew had a similar problem...first, it would not go past the startup screen, the next time I started it, it kept rebooting the system, and then after sitting overnight, it finally went blank on starting the car. I disconnected the negative terminal and left it disconnected for over 30 minutes and after dropping the nut into the battery cradle and spending 2 hours finding it, reconnected it and now all is well.