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EV mode questions. Why can't I get into EV mode?

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by wstt, Jul 22, 2013.

  1. wstt

    wstt Member

    Joined:
    Jul 11, 2013
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    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    At times I want to get into EV mode and when I press the button, it just beeps and won't let me go into EV mode. I make sure the a/c is off, and the fan is just blowing air at a slow rate. I'm moving, but barely giving it any gas if any at all. I am driving at speeds below 42mph and the battery has more than 50% charge. Anyone know why?

    What is the fastest you can drive in the EV mode with the EV button pressed?
    What is the fastest you can drive in Econ Mode (button pressed) where the car is in EV mode (EV is lit up on the left side of dash)? (It appears about 42mph)
    When driving on the highway on a slight downhill, I come off the throttle at about 60mph, so no bars (or maybe 1 bar) are on the left side of the power / charge meter. When I look at the center touch screen display showing the wheels and power flow, sometimes I see power still flowing back to the battery even though the power meter shows no bars charging or delivering power. Is this correct?
    Also sometimes, with 1 bar of power being delivered on the power / charge meter, and at 60mph, the touch screen display in car mode shows electric only power going to the wheels. Is this correct? I thought someone had said the electric mode didn't work at speeds that high.

    Finally when driving 40 with the ICE on, is there a trick to getting into EV mode? I usually do it by coming fully off the throttle, but does just coming partially off the throttle work?
    Thanks in advance for any insight and guidance into this.
     
  2. Jzerocsk

    Jzerocsk Member

    Joined:
    Nov 28, 2012
    108
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    Vehicle:
    2012 Prius v wagon
    Model:
    Two
    The EV button will never work over 25MPH. Otherwise whether it works or not is based on how the computer is feeling...there are a lot of reasons it will deny an EV-only request, but it's difficult to know why.

    25 MPH
    I think it's officially 46MPH.
    From what I have read, in Gen 3 (and Prius-v) it is very difficult to make the Energy display show no power flow for any length of time. Owners with scanguages have reported that as long as you have 0, 1 or maybe 2 pips above the regen zone on the HSI there is minimal power flow going on.
    The ICE has to turn in order to protect the electric motors from over-revving, but the wheels/momentum/gravity are doing most of the work turning the engine. At these speeds the electric motors still help turn the wheels to give you improved fuel economy, especially when the battery is fully charged.

    Pulling partially off works sometimes, but not always. Pulling off completely just about always works.
     
  3. drysider

    drysider Active Member

    Joined:
    Apr 14, 2008
    823
    332
    1
    Location:
    Liberty Lake WA
    Vehicle:
    2012 Prius
    Model:
    Four
    You will need an OBD device to accurately monitor the energy flows. There is a "scan gauge for dummies" tutorial that you can search for. ECO mode does not have a speed limitation. Driving in EV mode (button pushed) is not an especially efficient use of the battery. When you get into EV (no button) on the system indicator, using the battery to extend your glide will allow the battery energy to be more efficiently utilized.