2012 Prius PHV Resetting Itself

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by Scott Bauer, Feb 26, 2026 at 7:46 PM.

  1. Scott Bauer

    Scott Bauer Junior Member

    Joined:
    Jun 3, 2012
    2
    0
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    Location:
    Fremont, CA
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Advanced
    I'm driving a 2012 Prius PHV with just over 300,000 miles on it. With the exception of having to replace a catalytic converter that went bad (i.e., not stolen or ruined in such an attempt) several years ago, the car has done great mechanically all these years and miles.

    Recently however, it has started to have some "weird" electrical issues. Sometimes when I start it it appears as if the accessory battery has been detached (the EV mileage range indicator reads 14.1, the address book in the navigation system is unsorted, and other anomalies (including a new one a couple of weeks ago - when started the navigation display displayed what looked like a hard disk drive animation and had a message that said something about loading the system). However, the battery has not been disconnected, and the car starts up and drives just fine.

    I'd suspect a short of some kind, but given it otherwise starts and runs okay, having a short that only happens when it sits in the driveway seems a bit unlikely. (I have checked as best I can without taking things apart and I see no sign of rodents or other creatures that might be eating/jiggling wires... but if no one else has any ideas I might have to go with this possibility.)
     
  2. Brian1954

    Brian1954 Senior Member

    Joined:
    Jan 31, 2021
    2,370
    953
    0
    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    How old is the 12v battery?