Prius C Started on it's own

Are you sure you shut it off earlier?

 

Yeah, I would guess that the car wasn't shutdown earlier.

 

hope its parked outside, the exhaust fumes will kill you if its in an attached garage, disconnect the 12 volt battery if you leave it inside

 

Observe it again and make sure the garage door is open and your headed in so the exhaust is pointing out toward the garage door.
That or as others have suggested leave it outside for this test.

 

christine?

or maybe you got a gm ignition switch.

 

That was a good yarn.

 

Next time it happens, take a cell phone vid and THEN start the warranty dance.

Unless you have remote start, there aren't many other ways for the vehicle to be running without the key in the ignition.
You may also consider locking the car inside the garage (you'd be surprised how many people don't) and leave the door cracked for positive ventilation.

Now is a good time to check and see if you have CO detectors! Note the pluralization!!
If you don't, get them immediately, and not just for 'Christine.'

Good Luck!

 

Maybe leave a GoPro running inside the car for proof.....for the dealer to see it actually happen.

 

The beep of the car indicates it was unlocked by some action by someone. Using a metallic key requires fewer start steps than a push button smart key. It takes a moment to start a car with a key. You leave some details out. When you approached the car, was it running without a key in the ignition? If it could run without a key in the ignition then it could have been on for eight hours. Not having a key in the ignition may be a non issue with the car although I hadn't heard of it. If you were given the key slot of a key system and the mechanics of a smart key system, then merely taking the key out may have little effect on turning off the car. Bring it to the dealer without any testing and get them to look. They may need to change your ignition innards.

 

do you live near a military installation?