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Combination Meter or 12V Battery?

Discussion in 'Gen 2 Prius Main Forum' started by Brave Little Toaster, Sep 21, 2016.

  1. Brave Little Toaster

    Brave Little Toaster Junior Member

    Joined:
    Oct 4, 2014
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    Location:
    Kansas
    Vehicle:
    2005 Prius
    Model:
    N/A
    My Combo Meter/Speedometer quit displaying, not allowing the car to shut off or the rear hatch to open. It always comes back after I reset by unplugging the electrical connector over the 12v battery. The problem usually happens after the first drive of the day, when I restart the car the issue appears.

    The 12V battery is a TruStart brand and using the info screen sits at 12.4 volts with accessories on and 12.1 volts after hitting the start button without the brake, headlights on will put it at 11.8. Seems to hold just fine. With the vehicle on, the system charges at 14.0 volts, and starts reliably.

    I do not know the age of the battery. I would rather not throw $150 down the drain if its the combo meter. The only thing that concerns me is the combo meter ALWAYS comes back on after the reset. If it were an intermittent problem with the Combo meter, I'm curious why the hard reset would always make it work normally again. This symptom in my research tends to point more toward the 12v battery.

    Another thing I notice is the fuel gauge will read completely empty even though there's fuel after the reset. At some point it either corrects itself or the combo meter blacks out again.

    Thoughts?
     
    #1 Brave Little Toaster, Sep 21, 2016
  2. exstudent

    exstudent Senior Member

    Joined:
    Jul 11, 2009
    2,214
    902
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    Location:
    Torrance, CA
    Vehicle:
    2007 Prius
    Keeping Power button depressed for a few seconds will force the car OFF.

    Hatch not opening might be a bad button on hatch? Just a coincidence that it is occuring with the combo meter.

    Disconnecting the 12V battery causes the fuel gauge to loose memory. Reconnecting the 12V battery causes the fuel gauge to recalibrate as it tries to figure out the fuel level.

    12V battery readings look acceptable. Maybe an overnight charge w/ a smart 12V AGM compatible charger to bring the voltage readings up a little higher.

    At the end of the day, it still looks like a combo meter problem. You are likley out of the enhanced extended warranty period (9years/unlimited miles from first vehicle service date (first owner sale date)). Call Toyota customer care and ask for goodwill assistance. If younare lucky, maybe they cover 50% -100% of the bill.
     
    #2 exstudent, Sep 22, 2016
  3. Lemon_Prius08

    Lemon_Prius08 New Member

    Joined:
    Dec 15, 2019
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    Location:
    Los Angeles
    Vehicle:
    2008 Prius
    Model:
    I
    Did you ever figure out a solution to this issue? I'm going to replace the combo meter but I just bought this battery and don't want to buy another one. Thanks!
     
    #3 Lemon_Prius08, Dec 15, 2019
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