I left my Prius 2, which only has 12 months, and 4000 miles, in the parking lot for 12 hours. When I came back, the fob wouldn't work. The remote opening wouldn't work either. I had to open the door with the emergency key. When I pressed the power on button, nothing would happen. No lights, no sound, no response... the car was absolutely dead. What can I do? Is it a problem of the 12v battery? or the 400v? Can a Prius 2 be started with jumper cables on the 12v battery? Or should I just call the Toyota official dealer? Please help, I really don't know what to do. Thank you very much, David.