2012 Prius Got home from driving. Then 15 minutes later went out to the car to head out again. Car would not start or recognize key fob. One of the two. Headed back to my computer and researched how to charge key fob. Went back into car, pressed down brake and held key up to start button. Have done a lot of variations of this. The light with the key and car on it was flashing periodically. Got new battery entirely for fob, installed and still could not start car. Tried the key charging again. Still nothing. At one point I was able to turn the radio on but the display did not come on for the car itself, just the radio and sound. Is this a car battery problem? I have not replaced the battery yet.
Sounds like a bad 12v auxiliary battery. No dash warning lights? If you can, carefully, jump start the car, then you'll know it's the 12v. FYI, we're still on our original 12v battery on our 2011. Have you ever run the battery down low, so that it's been required to be jumped previously? Discharging battery down that low can take life off of the battery in the long run.
I once ran the battery out when leaving the door open on accident. We had to jump but that was a year ago. Do you have a suggested video or walkthrough on jumping a prius? I know this is a hot topic and I've been confused on how to do it successfully. My wife has a Toyota Matrix we can use.
Use the positive jump terminal at the back of the engine fuse box, the one with the red plastic cover over it. The negative is any good solid bolt, usually the shock tower is OK. Make sure you connect terminals on the donor car correctly, it doesn't need to be running.
It's tempting to clamp the negative jumper to the ground wire/bolt on the inverter because it's easily accessible. However, you might get a "Check Hybrid System" error following the jump due to an unexpected ground detected at the inverter. It's nothing, but it will freak you out when you see the message on your dash display. Best to avoid getting that error in the first place.
welcome! no, your just powering up electronics. btw, once you've run down the battery, it reduces the life greatly. also, the jump terminal in the fuse box only has metal on one side.
Got it all figured out! Seems the battery was dead and coincidentally my key was failing as well. Thanks so much with the help!