Recreational Vehicle Lpg Tank Valve/gauge problems of the 2008 Toyota Prius

The dashboard lights go out, meaning you can no longer see the mph, the fuel, and everything important to drive with gauges. This can happen at anytime, driving or parked, on any street in any weather. Also note, you can no longer shut the car off, unless you hold the start button for 20 seconds. Sometimes the car will still not shut off, it's also sometimes hard to tell if the car is off, because there is no more dash. The only well to tell is to see if the radio goes on. There are a few ways to reset this major malfunction, to try and get things working again by disconnecting batteries, but this is a dangerous problem, that could kill someone while driving and needs attention and recalled soon as possible!.