mooretime05

I have a 2007 GMC Sierra Crew Cab and i had my mechanic by pass my AVIC D3. It worked for about 5 minutes and then said My parking break was detected and my screen went blank. At stop signs it comes on again but as i go it shuts off. Can i shut down my Navigation while driving with a dvd playing? do i need to bypass the navigation? or is there something my mechanic might have done wrong??