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Engine runs when <25° even when in EV mode. Normal?

Discussion in 'Prime Main Forum (2017-2022)' started by dmigel, Jan 17, 2018.

  1. dmigel

    dmigel Junior Member

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    Mar 13, 2010
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    2010 Prius
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    II
    This is likely not an issue but just looking for confirmation that it’s normal for the gasoline engine to sporadically kick in when it’s really cold outside (<25° F) even when its in EV mode. I haven’t figured out exactly what buttons are pressed as far as heated seats, defrost, heat etc to determine correlation. But I’m just looking for someone to tell me it’s normal for this in certaiN Circumstances.

    I was led to believe that in EV mode it would only use battery power no matter what until depleted.
     
    #1 dmigel, Jan 17, 2018
  2. wb9tyj

    wb9tyj 2017 Prius Prime Advanced

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    normal...the colder it gets the more probable the gasoline engine will run, even though you are solely in EV...Additionally, when turning on the defrosters the engine will turn on...so your observation is normal...
     
    #2 wb9tyj, Jan 17, 2018
    dmigel likes this.
  3. dmigel

    dmigel Junior Member

    Joined:
    Mar 13, 2010
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    St. Louis
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    2010 Prius
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    II
    Thanks. Just wanted to make sure I didn’t need to get to the dealer.

    Found this forum to be super valuable.
     
    #3 dmigel, Jan 17, 2018
  4. DavidA

    DavidA Prius owner since July 2009

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    Jul 14, 2009
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    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    With no accessories on (cruise control, heated seats, heated steering wheel, either of the window defrosters, or cabin heat) the car is supposed to start in EV mode above 14 degrees. Here's the kicker though...

    Let's say that the air temp on the MID says it is 25 degrees outside, but overnight it was much colder; 5 degrees? It will take many many hours for the battery temp sensor to warm up to match the daytime temperatures. I've had my Prime gas engine ("ICE") start right away in the upper 20's under similar conditions. I've also had the car start in EV mode at only 15 degrees, and stay in EV. The car does what it thinks it needs to do.
     
    #4 DavidA, Jan 17, 2018
    Trollbait likes this.
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