So my prius started doing this 3 weeks ago. I would turn it off and then sometimes itll turn itself back on in accessory mode. One time i turned it off and sat in the car for like 10 minutes, it turned it self back on. Doesnt happen every time but it does happen often enough its messing up stuff like resetting my miles meter in the energy monitor and sometimes itll turn off my AC when it turns it self back on. Heres a video
Try to turn off the smart key system and only use the key in the slot. If you take the key out it can't turn back on? So it's just peeping? Or does it still turn back to ign-on?
Just a guess. The power button is physically or electrically sticking. So it thinks your holding the button down?
Basically what the test on my previous post is testing. If control unit sees the button pressed without the key in it peeps. If it's a problem with relay control unit etc. it will still power on.
Mines doing same thing there has been a bunch of posts about this with no confirmed resolutions so I'm bringing them back from the dead. Did you ever figure out what was going on? turn it off, and it turns back on and climate, clock, odometers reset.
Your issue sounds like a 12 V power supply issue to me, in that the power is intermittently going on and off. Check all the connections at the 12 V battery in the back. All three (the positive connection on the battery, the negative on the battery, and the ground connection to the car body) should be clean (free of all corrosion) and tight. Check that out and post back if there is no change.
Im wondering what happened, did you figure it out? Was it the 12v? My 09 lately started doing the same thing, but my 12v is brand new and checked and works fine. Right now, im locked out of my trunk and cant even reach the 12v...the car is completely dead.