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New 2012 Prius Two with hum when operating on battery alone

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by priusrat, May 16, 2013.

  1. priusrat

    priusrat Junior Member

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    I noticed it literally when pulling off the lot when I bought it. I only hear it when the car is in drive or reverse, only when gas engine is not running. It is a specific pitch hum. It stops when I hit the brake, and begins again as soon as I take my foot off the brake pedal, only when transmission is in gear. My 2010 Prius II doesn't make this noise. Any ideas?
     
    #1 priusrat, May 16, 2013
  2. bisco

    bisco cookie crumbler

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    noisemaker? does it stop over 15 mph?
     
    #2 bisco, May 16, 2013
  3. Paradox

    Paradox Prius Enthusiast / Moderator
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    Yeah, definitely sounds like the Vehicle Proximity Notification System (VPNS), or noise maker lol.
     
    #3 Paradox, May 16, 2013
  4. priusrat

    priusrat Junior Member

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    I don't know, because usually the gas engine is on at this point. Does the 2012 Prius Two have a noisemaker like this that the 2010 didn't? It's a specific pitch - always the same note.

    I just listened to the video on line - mine doesn't sound quite like that, but I'm inside the car. Pitch doesn't seem to change, either, but I bet that's what it is. I'll get my kid to back it out of the garage while I listen. Thanks, guys. I was afraid I had bought a lemon.
     
    #4 priusrat, May 16, 2013
  5. fuzzy1

    fuzzy1 Senior Member

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    Is it a 'spaceship' noise? That is the sound of the intentional noisemaker Paradox mentions, new for 2012.

    (I also went from a 2010 II to a 2012.)
     
    #5 fuzzy1, May 16, 2013
  6. Paradox

    Paradox Prius Enthusiast / Moderator
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    Yes, the VPNS was added on all 2012 and beyond Prius models. Also, II or Roman Numerals were only used in 2010 for model designation. 2011 and on, it's two, three, four and five.

    And I as well went from a 2010 to a 2012.
     
    #6 Paradox, May 16, 2013
  7. bisco

    bisco cookie crumbler

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    it's definitely different in the video, much clearer.
     
    #7 bisco, May 16, 2013
  8. The Electric Me

    The Electric Me Go Speed Go!

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    As a driver I have found the best way to get feedback or be able to hear your own VPNS is to find a relatively quiet drive-thru, hopefully with brick or cement walls, and roll down your windows as you slowly drive through.

    That's about the only scenario where I have been able to hear my own VPNS from the inside of the vehicle.

    As far as your sound? I don't know. I'm of course NOT comparing my Prius to previous ownership and/or another Prius.

    Am I making a mistake? I have noticed a very slight sound when My Prius is running on full EV. But I haven't owned the Prius with the expectations that the Hybrid system would be completely silent. To me, the barely audible hum...doesn't sound like anything operating improperly, and the operation of the vehicle seems fine. So for me, I've been approaching some sounds from my Hybrid as simply being sounds I should expect from a Hybrid.

    Of course this is my first complete ownership, longterm of a hybrid vehicle and I'm comparing it most recently to a Honda Fit, which was a great automobile but as a sub-compact, "cough", not particularly quiet. The Prius even with added Hybrid sounds is 1000 times quieter vehicle in operation.
     
    #8 The Electric Me, May 16, 2013
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