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S4 (Stage 4) Temperature

Discussion in 'Gen 2 Prius Technical Discussion' started by tom1l21, Oct 26, 2009.

  1. hobbit

    hobbit Senior Member

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    I've mentioned the coolant-circulation period a couple of times;
    it's when the 3-way valve switches over to run engine-heated
    coolant through *everything*, including the bottle. The problem
    is that I still can't find the reference in the NCF or wherever
    I *know* I read the official description of this.
    .
    _H*
     
  2. ken1784

    ken1784 SuperMID designer

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    There are some descriptions at John's site.
    John's Stuff - Toyota Prius - 2004 Tech Presentation 38
    The slide 38 through 41 are shown them.

    Ken@Japan
     
  3. hobbit

    hobbit Senior Member

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    Right -- I have a local copy of that presentation, in fact, but
    while it shows the whole-system coolant path opening up via the
    3-way valve it doesn't say anything about additional deliberate
    engine-running to help circulate coolant through everything. I
    *know* I've seen that described somewhere, though! And I see it
    happening often enough in my own car.. using the ECT fakeout seems
    to trigger a bit more extra running, too, until things stabilize.
    .
    _H*
     
  4. hill

    hill High Fiber Member

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    I know that's how it is . . . but still I'm blown away sometimes. We're still having the occasional 80 degree days in November. Grill blocked 100%, driven for over 20 minutes ... charge is up over the 1/2 way mark ... slowing down from 45 to (for example down to 35-40) enter stealth ... and every once in a while the ICE simply won't kick off ... even though the S4 temps would necessarily mean that the ICE should kick off. The mysteries of life.


    That's likely what it is, but I never timed it. Seems like an eternity ... at least a couple minutes. I'll have to check it next time.
    .