1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Limiting engine startup in cold weather

Discussion in 'Prime Main Forum (2017-2022)' started by sylvaing, Oct 30, 2023.

  1. sylvaing

    sylvaing Senior Member

    Joined:
    Jul 15, 2023
    1,185
    495
    0
    Location:
    Canada
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Base
    Temperature is starting to get into the single celcius digit here and yesterday, it was just 4C when I used the car. I started the AC remotely using the fob (Base edition) and confirmed that the engine wasn't running, just the heat pump. I've let it run for about 5 minutes while plugged to my Level 2 charger.

    When I got in and started to go, the engine started and ran for the first 5 minutes of the drive (consumption was about 10L/100km) before it shut down and EV mode engaged.

    What can I do, if any, to have EV mode engaged at the get go in situation like this?

    Thanks.
     
  2. schja01

    schja01 One of very few in Chicagoland

    Joined:
    Apr 22, 2005
    1,765
    1,169
    0
    Location:
    Chicagoland
    Vehicle:
    2018 Prius
    Model:
    Prime Advanced
    Limit use of the defroster is one thing.
     
  3. sylvaing

    sylvaing Senior Member

    Joined:
    Jul 15, 2023
    1,185
    495
    0
    Location:
    Canada
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Base
    Oh, I did have the defroster on because when I got in, all the windows where fogged up from the inside. I don't think having started the AC remotely was a good idea.

    If I put the car in Ready mode while plugged in with climate set to Auto and the steering wheel heat and seat heat on for about 5 minutes before leaving, would that be better? Would it help warming up the battery?
     
  4. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,702
    39,241
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Any chance of garage parking?

    Block heater usage allows me to spoof our hybrid Prius ‘10 into leaving the engine off, at least for short, low-speed garage to driveway maneuvering.
     
  5. sylvaing

    sylvaing Senior Member

    Joined:
    Jul 15, 2023
    1,185
    495
    0
    Location:
    Canada
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Base
    Garage has been used for many years as storage unfortunately. Odd that we keep lots of worthless crap in the garage and an expensive car outside instead lol.

    This morning, at +1C, I turned on the defroster while plugged in in Ready mode with both the seat and steering wheel heaters turned On. The engine stayed Off but after a few minutes in the driveway, the air coming out was more cool than warm. It would take a long time to defrost a windshield that way. I had Eco mode turned On so I turned it Off and will see tomorrow morning if it makes any change. Before going, I disengaged the defroster and left the heaters On (and turned on the rear defroster which I forgot to do earlier) and set Climate to Auto. Air coming out was warmer. The engine stayed Off for the whole 20 minutes ride. I was in EV the whole time.
     
    Mendel Leisk likes this.
  6. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,179
    50,062
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i don't think you can run the front defrost without the engine, as a safety feature. you can try the defrost/footwell setting, but if that isn't enough, you're out of luck
     
  7. sylvaing

    sylvaing Senior Member

    Joined:
    Jul 15, 2023
    1,185
    495
    0
    Location:
    Canada
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Base
    Shouldn't the engine have turned on by itself while in Ready mode when I activated the Defrost while parked? It didn't.
     
  8. Andy2

    Andy2 Member

    Joined:
    May 9, 2022
    72
    51
    0
    Location:
    Edmonton Alberta
    Vehicle:
    2022 Prius Prime
    Model:
    Technology
    Yes, for me, hitting the front defroster button always gets the engine going, although there can be a delay. In fact, I treat it like the ignition button for the engine when I want to use the engine from the start, as on a cold Alberta morning or if I haven't used the engine in a couple weeks.
     
  9. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,179
    50,062
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    agreed, i think it should as well. test it again
     
  10. sylvaing

    sylvaing Senior Member

    Joined:
    Jul 15, 2023
    1,185
    495
    0
    Location:
    Canada
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Base
    So just tried it again (it's +2C) and the engine will start when the defroster is turned on while in Ready mode, but only if the car is unplugged from the wall. When plugged, engine doesn't start and the air coming out is cold.

    With Defrost off and plugged into the wall, if I take it out of Auto and set it to windshield and feet with fan set to Max and Eco Off, it still output cold air. Only when I unplug the car does it output warm air with the engine still off, so using the heatpump (but not as warm as in my Model 3).

    What surprised me is even with some air blowing to the windshield, I could still turn off AC and set it to recirculate. That was my prefered way (although full windshield air flow) to warm up the car without anyone inside in the morning in my cars in the 90s. That's the fastest way to warm up the cabin in my opinion.
     
    bisco likes this.
  11. sylvaing

    sylvaing Senior Member

    Joined:
    Jul 15, 2023
    1,185
    495
    0
    Location:
    Canada
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Base
    Ok, tested it this morning at 1C with the car plugged in and Climate Prep set to 9:30am (which was set at 8:45am with the car already at full charge from yesterday. There was frost on the car and the sun had started to strike the car at a 45 degrees angle from the driver side, so the frost was starting to melt from that side, but not the passenger side.

    At 9:20am, the climate started (but not the engine). At 9:30am, there was no noticeable change in the frost on the car. I unplugged the car, got in, turned it to Ready and activated the Defroster. Engine started right away and the air coming out was already somewhat warm so it looks like the Climate Prep did start to heat up the car, but with the sun striking on it, it was hard to tell if the warmth I felt inside was because of the sun heating up the cabin or the climate. I'll need to try it again at sundown to get a better picture of it. If there was warm air coming out of 10 minutes in Climate Prep, it doesn't look like it hit the windshield though since they remained frosted.
     
  12. Doug McC

    Doug McC Senior Member

    Joined:
    Feb 15, 2022
    1,014
    382
    0
    Location:
    Midwest
    Vehicle:
    2022 Prius
    Model:
    XLE
    The ECU is going to start the ICE when the engine is cold and run until it reaches operating temperature to protect the engine from damage. Even IF you could bypass that it would be foolish to do so.
     
  13. sylvaing

    sylvaing Senior Member

    Joined:
    Jul 15, 2023
    1,185
    495
    0
    Location:
    Canada
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Base
    Ok, so next step this morning. At 9:10am, I've set Climate Prep for 9:30am, set the climate for windshield and feet, AC Off and Recirculate On. Temperature outside was -1C and a light snow covered the car. The car was plugged in at 240V/16A (40A breaker) but already fully charged from the evening before. I added silk paper strips at all the vents to see which ones would blow air.

    At 9:20am, climate started and the windshield and feet silk paper strips were blowing, so it looks like the car kept the climate setting I entered. I'll try again tomorrow morning but with the climate set to Auto. Engine stayed Off the whole ten minutes.

    At 9:30, climate stop so better be ready by the time you've set the departure. I wish it would allow some leeway by letting the climate on for a few more minutes past the departure time. Only a very small portion at the bottom of the windshield had snow melted. Doing the same with my Model 3 would have had the whole windshield cleared up by that 10 minutes.

    Although the car was plugged in, the 240V/16A wasn't sufficient or never even used because when I got in at 9:31am, the car needed to charge for 30 minutes to get back to a full charge. That was disappointing.
     
    bisco likes this.
  14. sylvaing

    sylvaing Senior Member

    Joined:
    Jul 15, 2023
    1,185
    495
    0
    Location:
    Canada
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Base
    Sucks, turning Recirculate On do not stay after powering down the car. When not in the car (as in Climate Prep), recirculating the air is the fastest way to warm up the cabin. An analogy is it's faster to boil water in a kettle than a running stream of water.
     
  15. Trollbait

    Trollbait It's a D&D thing

    Joined:
    Feb 7, 2006
    22,454
    11,766
    0
    Location:
    eastern Pennsylvania
    Vehicle:
    Other Non-Hybrid
    It can also be a good way to fog up the windows, which is likely why the Climate Prep defaults to it off.
     
  16. sylvaing

    sylvaing Senior Member

    Joined:
    Jul 15, 2023
    1,185
    495
    0
    Location:
    Canada
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Base
    Hard to fog up when there is no one in the car (our breath fogs up the car fast when set to Recirculate) and that's when climate prep is used.
     
  17. Trollbait

    Trollbait It's a D&D thing

    Joined:
    Feb 7, 2006
    22,454
    11,766
    0
    Location:
    eastern Pennsylvania
    Vehicle:
    Other Non-Hybrid
    Little bit of snow or water left on the floor mats will quickly get into the air with warm air blowing on it.
     
  18. sylvaing

    sylvaing Senior Member

    Joined:
    Jul 15, 2023
    1,185
    495
    0
    Location:
    Canada
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Base
    Never gave me an issue with my previous cars using this method and there have been more than just a little bit or snow on the mats in the middle of winter.
     
  19. vvillovv

    vvillovv Senior Member

    Joined:
    Mar 19, 2013
    3,907
    1,338
    1
    Location:
    NY
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Plus
    It's possible to run preconditioning more than once.
    There are also times when preconditioning is disabled and no matter how many times the fob button is pushed the computer will not start the heat pump,
    I've also been able to run preconditioning without being plugged in, though not enough times to know what the parameters are for that to work.
    The colder the ambient temps the less efficient the Prime heat pump gets.
    Comparing Tesla behavior to Prime behavior is like apples and oranges. Programming has different goals, especially in colder weather and how efficiently heat is produced from the available energy sources.
     
    #19 vvillovv, Nov 3, 2023
    Last edited: Nov 3, 2023
  20. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,179
    50,062
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    too many phev owners want them to behave just like a bev
     
    vvillovv and Trollbait like this.