Lose Power Steering problems of the 2007 Toyota Prius

After the car has been parked for awhile, the dashboard was completely black. The car powered on, but there was no speedometer, no fuel display, and no odometer. The car will drive and gas engine and hybrid system works as usual, but there are no power steering, the turn signals do not work, and the wiper does not work. After driving for 5 to 15 minutes, the dash would light up and car drives like normal again and the problems mentioned go away. Based on internet research, this seems to a common problem. There are almost identical complaints on this site including NHTSA id number 10544698. Significant safety concerns exist due to the temporary lost of power steering, no turn signals, and no wiper during a rain.