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Throttlebody whine

Discussion in 'Generation 1 Prius Discussion' started by gothstone, Oct 17, 2019.

  1. gothstone

    gothstone Junior Member

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    Working on my P3101 and P3191. After the engine dies the throtlebody motor makes a high pitch whineing sound. Is this normal on the gen 1 prius? It did this before i cleaned it, and continues after.
     
    #1 gothstone, Oct 17, 2019
  2. ChapmanF

    ChapmanF Senior Member

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    Funny, I had never really noticed it in my Gen 1, but it's really prominent in my Gen 3 whenever I'm working under the hood.

    Yeah, the ECM holds the throttle in the selected position by sending a train of pulses to the throttle motor, one direction or the other. The pulses are at a frequency you can hear.
     
    #2 ChapmanF, Oct 17, 2019
  3. gothstone

    gothstone Junior Member

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    It might not be very noticeable to most people. I used to tell my maint crew at work when a florescent ballast was about to go out because the high pitch sound they make hurt my ears. Of course they tough I was nuts, but after they saw I was right about the first couple they just started replacing them any time I complained about one.
     
    #3 gothstone, Oct 17, 2019
  4. ronlewis

    ronlewis Active Member

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    There's a Tom T. Hall song about that - "Old dogs, children, and throttlebody whine."
     
    #4 ronlewis, Oct 20, 2019
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