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3rd gen vs. 2nd gen questions thread

Discussion in 'Gen 3 Prius Main Forum' started by cwerdna, Feb 17, 2010.

  1. cwerdna

    cwerdna Senior Member

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    I'm not sure if there's an existing thread for this but I propose this be a thread for curious 2nd gen owners to ask 3rd gen owners some questions about differences compared to the 2nd gen.

    I've seen the 3rd gen in detail several times and have test driven a pre-production one 2x but these questions couldn't be answered from those experiences.

    Here goes:
    - Does the 3rd gen still have the behavior where if the ICE is cold, the ICE might run to provide cabin heat. If in this state, if one turns the HVAC (turns fan to off), will the ICE shut down, regardless of the temp setting? Will ICE start back up if then fan is turned on in this state?
    - If yes to the 1st question, what's the temperature cutoff/boundary? On the 2nd gen, it was 145 F for FWT (Fahrenheit water temp) per Scangauge.
    - With a 1-key SKS car, will the car still emit a long beep and refuse to lock the doors if the SKS is left somewhere in the car, including the trunk area?
    - Are there still "5 stages" of operation like the 2nd gen?
    - Can one defeat the initial ICE starting by pressing the EV button? Can it be done always or only in certain cases? (I tried this on my one week HS 250h test drive and in some cases, it just refused and said it was "unavailable" when the engine was cold).
    - Are you always given good reasons on the displays why EV mode was denied/refused beyond battery too low, excessive acceleration or excessive speed? (HS 250h reported most of these but also many times just said "unavailable". The manual listed WAY more reasons.)
    - What's the max speed for running in EV only (ICE at 0 rpm)? It was ~42 mph on the 2nd gen.
    - What's the highest # of amps you've seen go to/from the HV battery? It was the BTA XGauge on the 2nd gen.
    - How many amps (BTA) are drawn from the HV battery when "idling" (stopped)?
     
  2. eglmainz

    eglmainz New Member

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    While I own a 2010 Prius V, Navi, and have never owned a 2nd Gen Prius, I will do the betst to answer the ones that I know… (I inserted numbers on your questoins, to keep track.)

    1- Yes. If the cabin is cooler than the ICE, it will cycle the ICE in order to maintain temperature set by climate control system thermostat. If you turn off the HVAC system during this time, and you are parked, (or not demanding Iceacceleration), the ICE will shut off (assuming it was been warmed up) Then, if you turn the HVAC system back on, it will engage the ICE as needed to maintain.
    2 - No scan guage, so I cannot answer this.)
    3- Yes, the SKS system will still recognize the fob in the vehicle, and should sound an alarm.
    4- Unknown
    5- Just like on the HS-250h, sometimes you can, sometime you cannot. (What is the benefit of this?)
    6- As this has similar system 'brains', the messages sounds very similar on both. Sometimes you are told why it's unavailable, and othertimes simply told 'unavailable'.
    7- I have seen it said it was 46, but I have been able to get my car over 50 on a long straight country road without traffic, using only EV, and not ICE. (At least displayed on the MFD - I do not have scanguage to confirm this).
    8- Unknown.
    9- Unknown.
     
  3. ScottG10

    ScottG10 Member

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    Does the cabin use a traditional coolant type heater? I thought I had read someplace that it used electric resistance heating.
     
  4. Spartane

    Spartane Member

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    I'll try:

    1. Yes - turning off the fan allows the engine to turn off if the water temperature is higher than 103F, regardless of the heater control's temperature setting (I like it warm so I generally leave my temperature set to 86F).
    2. The temperature cut-off boundary changes depending on whether or not you're in ECO mode. In ECO mode I believe it cycles between 123F - 136F (those numbers may be off by a bit since I haven't measured this is a while), regardless of the fan setting. In Normal mode, it may be the same (or it may be slightly higher by a couple of degrees or so), unless you turn the fan speed up just past half way. Then the temperature fluctuates between about about 131F (not really sure of the exact lower number) and 148F. I think PWR mode works the same as Normal mode.
    3. Yes, the SKS works the same way.
    4. Don't know.
    5. In my opinion, the EV button is fairly useless. You'd like to use it to jockey the cars around on the driveway without starting the engine, but it always seems to start up within about 15 seconds, and if it's cold enough it starts almost immediately.
    6. During the summer, I think I was able to select EV mode within the first 15 seconds or so and stop the engine from starting up. But it had to be quite warm outside or EV mode would not engage (don't know the temperature), and even then it would exit EV mode after about 10 MPH since the engine was not up to temperature. In general, it seems that the car is always giving some excuse as to why it won't go into/stay in EV mode. Sounds like you already know most of them.
    7. The times I've tried to use EV, I've found it always seems to exit with an "excessive speed" message after 25 MPH, even with a warm engine.
    8. I've seen 130 AMPS coming out of the battery (usually for engine start) and I've seen 83 AMPS going into the battery during braking regeneration.
    9. I typically see about 2 to 2.5 AMPS pulled from the battery while sitting idle in "D" with the engine stopped.
     
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    All Prius have the traditional heater core which is heated by engine coolant, as well as supplemental PTC electric heaters.
     
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  6. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    #5) yes...

    i know everyone else said no and they are probably right.

    have a nice day!!
    '
    '
    '
    '
    ok, maybe i should explain;

    we all know the real advantage the Prius has over other wannaby hybrids is their battery management system and how it integrates into the Synergy drive system. that is why the Prius is bigger, faster, AND more economical than its competitors.

    *the EV mode works immediately upon startup as long as;

    1) there is a sufficient amount of charge in the traction battery. a few bars will do it
    2) speed is under TEN MILES PER HOUR

    *EV mode works when car is warmed up as long as;

    1) see #1 above
    2) speed is 25 mph or less


    **other commments**
    regen on 2010 works at all speeds, including speeds under 7 mph.

    the engine is not tied to the heater control as closely as the 2006. i could toggle the engine on and off on the 2006 by simply hitting the defrost button. my 2010 does not do that.
     
  7. tumbleweed

    tumbleweed Senior Member

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  8. cwerdna

    cwerdna Senior Member

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    Interesting... thanks for the answers!

    For 1 and 2, is your 103 F a typo? Did you mean 130 F? That is interesting that the ICE on/off boundary is different depending on the mode and has a range. It sounds like it might be tough to tell how low to let FWT drop before shutting off the heater or when to not turn it on.

    On the 2nd gen, after you were at or past stage 2 (?), the boundary was strictly 145 F.

    Hmm, only 83 amps going into the battery during regen? If seen as high as 9x amps of regen (shows as -9x.x) on my 2nd gen.
     
  9. tumbleweed

    tumbleweed Senior Member

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    I just did some tests for another topic and this is what I observed:

    I didn't notice during engine start as Spartane did but during heavy acceleration (full throttle) at low speed with the battery at 6 bars or over it will draw 120 Amps max, then as the ICE RPM increase the current draw will drop off; under regeneration with the battery down to 3 or 4 bars I have see over 100 Amps going into the battery if you really come down on the brakes. I say over 100 because the ScanGauge won't display more than 99.9 Amps in the charge direction, probably because of the sign bit. When the battery is up to its normal 6 bars I see about the same maximum regen as Spartane does, 80-85 Amps.

    I also see 2-2.5 Amps at idle but it can be more or less depending on what is turned on (i.e. heater fan, lights, etc.) with everything off I see around 1.6.
     
  10. Spartane

    Spartane Member

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    No typos; as long as you have the heater system turned off, the engine shuts off at 103F.

    When I start my drive in the winter, I try to keep the heater off until the water temperature hits at least 130F. Then I put it on recirculate for 5 to 10 minutes and blast the air on the top setting to try and warm up the interior. During this time, if the outside temperature is sitting at about 10F and if the car is moving slowly through stop-and-go traffic at 1280 RPM, the water temperature stays at about 130F. Within the first 10 minutes or so, the interior is usually warm enough so that I can lower the fan speed down half way. This lower fan speed is enough to allow the temperature to rise to about 136F where the engine can shut off (instead of 148F).

    The battery charge may well have exceeded 83 Amps on occasion, but that's the number that I remember seeing most of the time when I did moderate to heavy braking.

    While sitting at a stop light during warmup at 1280 RPM idle, it's fairly common to see a persistent charge rate of about 20 - 22 Amps, which gradually reduces to zero as the seventh bar lights up. You can actually hear the gears spin up just before the Scangauge reads the full 21 Amps.

    I've seen very brief peeks of about 103 Amps or more from the battery when punching the gas pedal while the engine was already running, but this rarely lasts for more than a second or so.
     
  11. cwerdna

    cwerdna Senior Member

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    Sorry, been too busy to revisit this thread and grok your response.
    I think there's some confusion as to what I was asking. I understand what you mean about the engine shutting off at 103 F now.

    But, I was really asking a different question. On my 2nd gen, if FWT is <=145F and I have the heat on hi and fan at any position other than off, the ICE will run to provide cabin heat when stopped and at low speeds.

    So, if FWT <=145 F, if I'm stopped (and assuming I'm past the warmup stage (2?)), the moment I turn the fan off, ICE turns off. If I turn fan on, ICE starts. If FWT >145 F, assuming I'm stopped and the HV battery isn't too low, the car will not start/keep the ICE running to provide cabin heat.

    It sounds like on the 3rd gen, the cutoff isn't fixed value but is somewhere between 123 to 136 F, depending on mode or other circumstances. Right? Or is it 123 to 148 F?