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When system determines the gas engine is needed

Discussion in 'Prime Fuel Economy & EV Range' started by CraigM, Jan 4, 2018.

  1. CraigM

    CraigM Active Member

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    Vehicle:
    2017 Prius Prime
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    Prime Advanced
    page 87 of the manual:

    Gasoline engine operation in EV/EV auto mode
    Even if there is a sufficient amount of electricity remaining in the hybrid bat- tery (traction battery) and EV driving range (→P. 199, 215, 222, 239) is being displayed on the multi-information display etc., EV driving (driving using only the electric motor) may be canceled and both gasoline engine and electric motor are used depending on the situation (EV driving will be returned to automatically after EV driving becomes possible again).
    EV driving may be canceled automatically in the following circumstances:
    ●When vehicle speed is more than approximately 84 mph (135 km/h).
    ●When power is needed temporarily, for example when the accelerator pedal is depressed firmly or when accelerating suddenly.*
    ●When the temperature of the hybrid system is high.
    The vehicle has been left in the sun, driven on a hill, driven at high speeds, etc.
    ●When the temperature of the hybrid system is low.
    ●When the heater is switched on when the outside temperature is below
    about 14°F (-10°C).
    ●When the windshield defogger switch is pressed. (→P. 491, 501)
    ●When the system determines that the gasoline engine needs to be started.
    The gasoline engine may also operate in circumstances other than those listed above, depending on conditions.
    *: When traveling in the EV auto mode only

    ———————————————————————————————————————————-
    I’m wondering about the last bullet “may operate in circumstances other than those listed above”. I came home from a trip and noted Entune reports my fuel consumption as 498.7mpg instead of the expected 999.9mpg. The temperature was in the mid/high 40s. No heater / defogger used. Speed was under 50mph, easy driving. Arrived home with 3.2 Electric miles remaining.

    It HAS been approximately 30 days since I’ve knowingly used the ICE in HV Mode. Could the “system” demand some ICE usage every month?
     
  2. bisco

    bisco cookie crumbler

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    i'm not sure if this has been determined yet, but one owner got a message on her screen, something like 'oil reconditioning in progress'. whatever that means.
     
  3. CraigM

    CraigM Active Member

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    Thanks. I now recall that thread. Didn’t see any message on the screen, but if it just showed for a few seconds I might have missed it.
     
  4. CraigM

    CraigM Active Member

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  5. priuscatprimeguy

    priuscatprimeguy Senior Member

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    @CraigM have you seen the thread ICE comes on anyway? Long story short ICE kicks in when outside temperature is below 50 F and car is charged overnight outside not in a garage and cruise control is initiated.
     
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  6. JamesBurke

    JamesBurke Senior Member

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    on off on hack seem to be working? to cold for update to other thread?
     
  7. priuscatprimeguy

    priuscatprimeguy Senior Member

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    #7 priuscatprimeguy, Jan 5, 2018
    Last edited: Jan 5, 2018
  8. bisco

    bisco cookie crumbler

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    the pip runs the engine every 124 miles if it hasn't run to keep things fresh. iirc, nothing in the prime manual stating a definitive exercise time.
    it was a surprise to many former pip owners.
    however, some prime owners who thought their engine was never running, came to find out it had been when attention was called to their mpg's. they just didn't hear it.
     
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  9. DavidA

    DavidA Prius owner since July 2009

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    My Prime ICE is as loud as my Gen3 was. No problem hearing it. Those that don't probably have some hearing problems, are driving in a noisy city or traffic, or have the music too loud.

    27 degrees today and the ICE came on immediately. No heat or defroster, lights or heated seats or steering wheel - not even the radio. Strange. But that's what that last sentence says in the manual can happen "When the system determines that the gasoline engine needs to be started."

    It switched to EV just 5 feet from my parking space as I pulled in at work.
     
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  10. Son of Gloin

    Son of Gloin Active Member

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    Don't'cha just HATE IT when that happens?

    At the OPPOSITE end of that issue: While returning home from about a 70 mile trip (each way) out of town toward the end of November, I said to the wife: "Well, I think we MIGHT make it home from here in EV mode." So I switched it to EV. That was about 12 miles from home with 11 miles showing on EV range. When we pulled into our garage, available EV range displayed was 0.1........
     
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  11. zigzag

    zigzag New Member

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    Excel
    This happened to me this morning. I had the window defogger on. Temperature today is a lot colder than normal for the south of England -4C and I saw that the engine was on even though there was 50% battery still left. My journey to work is usually 2 miles longer than the battery lasts but today I arrived with 10 miles remaining and having seen the engine come on two or three times on the engine monitor.