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super cold weather system functionality???

Discussion in 'Gen 2 Prius Technical Discussion' started by kliffee, Feb 23, 2007.

  1. kliffee

    kliffee Junior Member

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    i am in fairbanks, alaska, and i have had my 07 prius for just over a week. last week the temps were hovering around zero (deg F) all week. i don't have a garage, but my prius has a block heater, oil pan heater and battery blanket (it is winterized). when i would turn on the car, i could start the interior heater fan by putting the climate controls in manual and selecting an appropriate setting.

    this week the temps have been dropping down below -20 at night. i didn't drive the prius at all monday. tuesday afternoon, after having the heaters plugged in for several hours, i started the car and let it run for 20ish minutes. when i came out, the heater fan was not blowing and i could not get it to blow. i drove it down the street and filled the tank. i drove it around the block a minute. but i was freezing, so i went home and left it running and called the dealer. when the service dept returned my call 15 minutes later, i went out to check on the status of the heater fan and found it running. this was approximately an hour after starting the car.

    is there an interlock that prevents the fan from running even in manual settings if the engine is too cold??
    if so, is there any way to override this?
     
    #1 kliffee, Feb 23, 2007
  2. efusco

    efusco Moderator Emeritus
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    Ok, couple interesting things you your post...
    1)Good for you, you're the first person from Fairbanks that I've heard of w/ a Prius...there are a few in Anchorage, but it's gutsy, esp. w/o a garage, to have one in Fairbanks.

    2)You HAVE to get me info on the battery blanket...this is probably the single think, at this point, that I'd like to have to improve my winter FE....

    3)I have no idea on the lock-out...are you saying that none of the vents were blowing any air at all? And you had the AC on full manual (AC off and Auto off?) and you still couldn't get the fan to come on? If you had it in Auto or AC mode I can see how it would lock out until the ICE temp (and maybe battery temp?) were up to some preset minimum. Did you have your battery blanket and Engine Block heater plugged in during that entire 3 day cold soak? If not I can see how you'd have trouble with some functionality....Even with just a 2 day cold soak at 20 degrees last winter my Prius showed marked decrease in performance and it took over 2 hours of highway driving for the battery to warm up to even 40 degrees (I have a CAN-View and monitor this stuff).
     
    #2 efusco, Feb 23, 2007
  3. kliffee

    kliffee Junior Member

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    1) there are actually quite a few prius here in fairbanks. but everyone else i know that has one also has a garage.

    2) the car came with the battery blanket installed. Auto Service Company, here in Fairbanks, did the winterization. so i don't have any details about that. but you could probably ask them about it.

    3) yes. no air at all. i tried all of the following:
    - AC/AUTO
    - no AC or AUTO, just fan speed.
    - front de-ice mode
    none of these options gave me any air. the ICE was running the whole time.
    i did not have the heaters plugged in for the 2 days the car was sitting in the cold.

    i was very impressed, however, with how easily the prius started after sitting in the cold. my 4runner and my RAV both make harsh engine noises when they start at those temps. but the prius just started right up with its typical nearly-silent awesome way.
     
    #3 kliffee, Feb 23, 2007
  4. efusco

    efusco Moderator Emeritus
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    I realized that maybe the battery blanket is for the 12v battery only...can you confirm which one it's for?

    I just wonder if the fan was so cold it just couldn't turn, I'm not aware of any lock-out that would prevent manual override from working.

    And yea, it just takes the tiniest bit of juice from the 12v to get the relays closed and ECUs booted up, once that happens the traction battery takes over...it's a pretty good cold weather car except for decreased performance due to a very cold traction battery.

    BTW, be sure to block your front grills, it makes a big difference in getting and keeping the ICE warm in cold weather.
     
    #4 efusco, Feb 23, 2007
  5. kliffee

    kliffee Junior Member

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    i am pretty sure that the battery blanket is just for the 12V battery.

    and, i had read about covering the grill (which is a common thing to do up here for ALL vehicles), but i can't imagine that covering the grill will help the ICE warm up when the car is sitting still.
     
    #5 kliffee, Feb 23, 2007
  6. member

    member New Member

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    Your car is working normally if you have your heater set to auto/AC. If on auto/AC and no air, then I'm perplexed. Mine does not do this to about -15F.

    When it gets that cold, put on a cloth car cover, or at least a thick blanket across the hood. Makes a world of difference with the block heater. I've had mine in -15F a couple times, once with and once without a cover. Big difference.
     
    #6 member, Feb 23, 2007
  7. JimN

    JimN Let the games begin!

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    <div class='quotetop'>QUOTE(kliff @ Feb 23 2007, 02:11 PM) [snapback]395341[/snapback]</div>
    Blocking the grill doesn't warm the ICE. Blocking the grill helps prevent the loss of heat that is already in the engine compartment. Same reasoning for the hood blanket.

    Even this far south partial grill blocking provides measurable to significant results. At worst, all this stuff is like chicken soup, it can't hurt.
     
    #7 JimN, Feb 24, 2007
  8. SomervillePrius

    SomervillePrius New Member

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    I'm still perplexed that the fan wasn't turning. I mean -15F is cold but not "THAT" cold, people in Canada routinely sees temperatures much lower then that. If it happens again (repeatedly) I would take it to the dealer and have it checked. Might be a bad fan connection?

    then again maybe it was just bad luck?
     
    #8 SomervillePrius, Feb 24, 2007
  9. Rangerdavid

    Rangerdavid Senior Member

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    I too remain perplexed by the fan not running. The Efusco is correct, there is no "lock out" feature that would have prevented it from running. I'm just wondering is perhaps there was some moisture that may have frozen and prevented the fan from running until the car warmed up enough to melt it. Could have only been just a drop of humidity at those temps, but I realize thats a bit contradictory... at those temps, there's generally not much humidity.

    still perplexed.......... :rolleyes:
     
    #9 Rangerdavid, Feb 24, 2007
  10. tomdeimos

    tomdeimos New Member

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    Fan should normally be off till engine warms enough to heat the air. I have to drive about 5 miles before my fan starts in auto mode when car starts out cold just in the 0 to 10 degree F range.

    If you don't block the air through the engine compartment up where you are the engine will never get warm.

    If you press the front defrost button that should force the fan to run. I think going to manual and max temperature will also start the fan going, but you won't feel much heat till the engine is brought up to 130 deg F or higher.
     
    #10 tomdeimos, Feb 24, 2007
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