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Car changing drive modes itself while driving

Discussion in 'Prius v Main Forum' started by Sarmac, Feb 24, 2022.

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  1. Sarmac

    Sarmac New Member

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    Hi all,
    2012 prius v with 106k here. Owned it about 1.5 yrs, since 88k. This has been happening for at least the past 4 months but may have missed it before.
    I typically drive in Eco mode. Originally I felt the car kind of hiccup / slight hesitation and glanced down to see it was in EV mode and it then immediately switched back to just Eco / engine kicked on. Thought I might have hit the button on accident, but once this happened several times, I knew better.
    I was worried because I didn't know if the engine was hesitating to turn on when in demand or....?
    Then yesterday this happened so I was paying special attention to the dash, and the car switched to PWR mode on its own. So I'm thinking there must be a short somewhere in the controls and that the hesitation I had felt previously was the engine kicking on as normal once EV mode was inadequate to power the car after having switched to EV on its own. Anyone else ever have this problem? Wondering if previous owners spilled their drink on the controls (poor placement, imo). Any likely fixes?
    Currently driving in regular mode to see if this still happens when not in ECO.
     
    #1 Sarmac, Feb 24, 2022
  2. rjparker

    rjparker Tu Humilde Sirviente

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    The car will switch out of Eco or Power to EV and back routinely. EV largely means the engine if off at lights, going downhill or after letting up on the gas a little. It is integral to a hybrid's operation to save gas.

    Switching to Power should not happen automatically but is easy to do inadvertently since the button is on the console next to your arm. It is possible a drink spilled into the button which "might" cause Power mode. I would look for it to happen again before spending money to replace it.

    The real advantage of Eco mode is not the amount of gas your engine needs to keep you at a given speed, instead it reduces ac and electric heat draws on occasion to save hv battery energy, which then requires engine operation to recharge in most cases.
     
    #2 rjparker, Feb 24, 2022
  3. bisco

    bisco cookie crumbler

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    check the 12v battery and connections. it should not switch out of whatever mode you have set, even as it switches back and forth from hv to ev. the ev light should simply come on when in ev.

    and consider cleaning the egr circuit if you haven't.
     
    #3 bisco, Feb 24, 2022
  4. rjparker

    rjparker Tu Humilde Sirviente

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    A v wagon switches in and out of EV following the motor running state. I would imagine a hatchback does the same.
     
    #4 rjparker, Feb 24, 2022
  5. Sarmac

    Sarmac New Member

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    There are 2 EV lights on the dash. One is on the left near the speedometer and goes know and off with nornal operation (yes I understand how hybrids work) and says simply "EV". The other, on the far right, is of course what I'm referring to ...it is the light that only comes on when you manually hit the EV mode button (or in my case, occasionally randomly) and it says "EV mode".
    If I hit the button and am going too fast / engine is running, it just blinks, beeps, and turns off. If I hit it when just the electric motor is running and I'm going slowly, it'll stay. It does kick out of this mode automatically if I accelerate, which is normal.
    My problem is that it's going into this mode on its own, and yes it's happened several times already. Sometimes a few times in a row...
     
    #5 Sarmac, Feb 24, 2022
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  6. Sarmac

    Sarmac New Member

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    Thank you! I will try that.
     
    #6 Sarmac, Feb 24, 2022
  7. bisco

    bisco cookie crumbler

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    yes, but not eco/normal/power modes. they only change with the button
     
    #7 bisco, Feb 24, 2022
  8. rampante550

    rampante550 Member

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    Have you spilled soda or something else on the switch? My buttons were sticking in the down position, so I replaced the switch itself. Maybe some liquid worked its way unto the circuit board; just something to consider
     
    #8 rampante550, Feb 28, 2022
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  9. bisco

    bisco cookie crumbler

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    excellent idea!^^^
     
    #9 bisco, Mar 1, 2022
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  10. Air_Boss

    Air_Boss Senior Member

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    Pepsi Syndrome...
     
    #10 Air_Boss, Mar 1, 2022
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  11. rampante550

    rampante550 Member

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    Here's excerpt from a short writeup I did with the parts number:
    1. For the console switch (84970-47020), I reference this video:

    • This guy does a great job on how to clean the switches, but I knew for me, I wanted to replace them (in the interest of time and not potentially causing harm)
    • If you too prefer to replace, you can skip the parts where he separates the silver piece from the black piece - it's possible and easy to remove the switch without removing any of the screws simply by spreading the cradle on both sides of one end and leveraging that end up, then repeating on the other to remove
    • To summarize - pop out the cupholder section, disconnect the wire, remove the console switch by applying leverage to release from the tabs, place in the new part, plug it in, pop the cupholder section back in (and you're done)
     
    #11 rampante550, Mar 1, 2022
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