About a month ago, my Prius c did not want to start at all and all the dashboard lights would come and stay on until I kept turning it on and off for about 5 minutes and it started working with no problem. The car was not being used at that point for about two days and it was pretty cold, so I thought it was the cold weather since I have never had this happen before. For about 2 weeks everything seemed fine, I had no problem starting the car, I was driving it daily without a problem. But once it was sitting on my driveway again for 3 days this time, it did the same thing again. It would not start at all for a minute and when it did start, all the dashboard lights came on and stayed on, this time it showed that the gas tank was empty (though I knew it was nearly full), the lights were dim when I turned it on and it made a pop sound, and it did not want to turn off for a few minutes. After almost 10 minutes later, everything worked fine and there were no dashboard lights on at all. The car worked without any problems The car worked fine until it sat in the driveway again for about 2 days, and had the same problems when starting it up. The hybrid battery has been charging normally throughout all the problems and it was more than halfway charged each time it would not start up properly. I bought the car used at 18,000 6 years ago and I have never had any problems. This has only happened in the last month or so and when I haven't driven it for more than a day.
Your 12v battery is most likely at fault and is telling you it's about to go to the great beyond. Prius' in general do weird things when that 12v starts to go out. Just so you know, most auto part stores do not carry a 12v battery that's a good fit for the Prius C. You can find alternatives, but it's just easier to go to the dealer and pick one up. Should you replace this battery yourself. Be extremely cautious not to cross polarity or you'll find yourself out hundreds of dollars more. It's just like on a regular vehicle: Negative to Negative / Positive to Positive Accidentally touch the wrong cable to the wrong post on a Prius though and you'll blow fuses you didn't even know you had.
The car's too old to take to a stealership... They'll only try to get every penny they can get from you for repairs until you give up and "take their advice" and buy a brand new car... But there's lots of relatively honest local mechanics who do hybrid car work in your part of the country. When dash lights go on error codes are stored till battery is disconnected or the code reader clears the codes. We can help you with least expensive fix if you tell us the error codes. You can do this yourself easy by using Dr. Prius app and an inexpensive OBD2 bluetooth reader: Hybrid battery diagnostic and repair tool for Toyota and Lexus
@Biancab --- Don't take your car to go get codes read. It's a 12v battery issue. The user is clearly describing the symptoms of a dying 12v battery Camper. Where's @Leadfoot J. McCoalroller & @Mendel Leisk when I need them?
Yep I agree with @dubit's diagnosis. The 12v battery is very likely shot. Getting 6 years out of a new 12v battery is very, very good. Getting 6 years out of a used one is miraculous.
and with a dead/dying 12v battery a Prius will report all kinds of phantom nonsense codes. A basic battery test is in order. If it confirms that the battery is bad, it's worth replacing. And very often, the car will start up with no codes at all.
no, there's nothing in the onboard diagnostics for this because it's much simpler and more accurate just to take a voltage reading at the battery terminals.