Some more questions about Prius 2010 and SG2

Discussion in 'Toyota Prius Family' started by aleniko, Mar 19, 2012.

  1. aleniko

    aleniko Member

    Hi all;
    I've began using a SG2 with my Prius2010, and I have a few questions:

    1. I seem to be able to pulse and glide at higher speeds, but this happens only 50% of the time. I can pulse to 65MPH and then when I glide, my SG shows 9999mpg. The problem is that sometimes the prius would just refuse to turn off the ICE at speeds higher than 41-42mph. I've learned that if I restart the car, it often helps. Any ideas how to achieve this consistently?
    2. When I do regular P&G the SG always shows 0.02GPH use. The funny thing is that when I achieve the above highway P&G it shows 0.00gph. Anyone can explain what's going on here?

    3. Is there a way for me to know what was the lifetime MPGs for the prius I own (If I didn't log all my driving?)

    Thanks!
     
  2. ksstathead

    ksstathead Moderator

    Above 45 mph, the 2010 must spin the ICE in D even when it has cut fuel flow based on you coming off the throttle.

    If you have completed the warmup cycle (not necessarily in Stage 4 even), you should always be able to induce fuel cut by coming off the throttle and easing back in just enough to remove regen from the HSI display. I don't use high speed P&G very much; there could be issues with some or all 2010's, though mine seems to cut fuel when I expect it.

    There may be a little hysteresis between 42 vs. 45 on the pure glide threshold.

    .02 gph is a common gen3 sgII error. Mine does that. No solution I know of.

    If you have cleared trip a and b, I think you've cleared mpg history. I use a for tanks, b for trips and testing, and a spreadsheet for cumulative.
     
  3. aleniko

    aleniko Member

    Thanks for your reply. Can yo clarify a few things?

    "Above 45 mph, the 2010 must spin the ICE in D even when it has cut fuel flow based on you coming off the throttle."
    What's the D stands for? Also, isn't the ICE a totally independent system in the Prius? How can it spin the ICE if the fuel is cut off?

    "If you have completed the warmup cycle (not necessarily in Stage 4 even)"
    Where can I get some more information about these warmup cycles?


    "there could be issues with some or all 2010's, though mine seems to cut fuel when I expect it."
    Do you think this is a software issue which I can ask the dealer to fix?

    Thanks!
     
  4. ksstathead

    ksstathead Moderator

    The output of the ICE is always tied to the output of both MGs in the power split device. And since MG2 is always tied to the wheels, the car's momentum spins the ICE when the software cuts fuel flow.

    See
    http://eahart.com/prius/psd/
    to understand the PSD of your hybrid synergy drive better. The big MG is the outer ring, the ICE is the planetary carriers in the middle, and the small MG is the sun.

    D stands for Drive on the shifter.

    I think there is a reduction gear in our 2010's, but the principles of the illustration still hold. This is closer to actual for 2004-2009 models.

    See priuschat here.
    http://priuschat.com/forums/gen-iii...-discussion/76501-gen3-warming-up-stages.html

    I reworked ken1784 of japan's post at post #10, so you can skip to that to save time.

    I don't think the dealers have a clue, and I have not heard of any TSB or other fix to it.
     
    Last edited: Mar 20, 2012
  5. aleniko

    aleniko Member

    A wealth of info. Thanks so much.
     

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