High Pitch Noise that wont stop and locks up the car

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by BeckyB, Oct 16, 2013.

  1. BeckyB

    BeckyB Junior Member

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    I tried to start my 2005 Prius this morning and a high pitched noise started (the same noise that happens when you hit the power button without having your foot on the brake). The emergency light was locked on as well as a message on the display screen about setting the emergency brake. This has happened one other time an after about two minutes the noise stopped, and I was able to start the car. This time the noise and lock remained for about 20 minutes until we disconnected the battery in the back. We re-attached the battery after we removed the ignition key and after a few moments all the power seemed to be gone. The fob doesnt work at all and the electronic lights and dash flickered and faded out. Our gut instinct is that the battery needs to be replaced. Has anyone had this problem before? Was it the 12V battery?
     
    #1 BeckyB, Oct 16, 2013
  2. Eclipse1701d

    Eclipse1701d Prius Enthusiast

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    That would be an excellent place to start considering the age of the vehicle. It's a no brainer if it's the original 12V battery...
     
    #2 Eclipse1701d, Oct 16, 2013
  3. 2k1Toaster

    2k1Toaster Brand New Prius Batteries

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    These exact symptoms are generally caused by a discharged 12v auxiliary battery. In your case, it could just be age. They run about $200. Preventative maintenance suggests replacement every 5 years no matter what in normal environments and 3 years in harsher environments with extreme heat or cold. These batteries are 99%+ recyclable.

    Having said that I have batteries that are decades old and they work fine. But I do not abuse them by running them down. They are essentially babied with the car driven pretty constantly and have never left lights on or doors open. Even 1 such event is enough to destroy the life of a battery. Just like 1 out of fuel drive on HV battery alone until there is not enough for even forward motive power will take a huge strain on the life of the traction battery.

    Do the standard 12v test. Let it sit overnight, measure at the battery terminals in the back or jumpstart terminal under the hood what the resting voltage is. Turn the car on but not READY, measure the voltage. Then turn the car to READY and measure the voltage. If the first number is around 12v or below, it is very dead. If the second number is around 11v or below, it is very dead. If the 3rd number is anything less than 13.8v you have a bad measurement, bad connection, or your inverter is failing.
     
    #3 2k1Toaster, Oct 16, 2013
  4. BeckyB

    BeckyB Junior Member

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    We changed the battery and the problem was fixed, however now my mileage is down 8-10 mpg. :( Is this normal? What might the fix be?
     
    #4 BeckyB, Oct 23, 2013
  5. Britprius

    Britprius Senior Member

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    When you change the 12 volt battery the car looses all it's settings, radio, drivers door window auto close, but it also looses settings it learns from your driving. This can increase in the short term the fuel used. It will re learn the settings.
    Another possibility is that the "new" battery fitted was not in a good state of charge, and that is now drawing large amounts of current from the Prius HV battery to recover. This again is short term, but can be alleviated by charging the 12 volt battery.

    John (Britprius)
     
    #5 Britprius, Oct 23, 2013
    cyberpriusII likes this.
  6. cyberpriusII

    cyberpriusII Prodigyplace says I'm Super Kris

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    John, just had to say, fantastic answer!(y)
     
    #6 cyberpriusII, Oct 23, 2013
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