I have a 2010 with 200k miles. It had been sitting for a couple weeks and when I went out to start it there was only one bar on gauge and it was flashing. Added a couple gallons for the hell of it, same thing. There was no leak or smell while it had been parked.
One bar and flashing means the gauge has forgotten how much fuel you have. Probably the 12 volt supply got too low (you may have had to jump the car?). As soon as it figures out the fuel level again, it will stop flashing and show the level. The ECM gives a P3193 code if it was going to give you a P3190 or P3191 and the fuel level reading was low at the time. As far as the ECM is concerned, a fuel level of unknown (because the gauge is still flashing and hasn't figured it out yet) is the same as 'low'. So if the engine tried to start while the gauge was still flashing, and didn't, that'll be a P3193.
Maybe someone siphoned the gas out of your car? Maybe rodents chewed up the fuel tank wiring? Posted via the PriusChat mobile app.