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Anyone Know Why Prius Has No Auto Off Feature?

Discussion in 'Gen 3 Prius Main Forum' started by Matt Hirn, Jun 22, 2013.

  1. saul

    saul Junior Member

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  2. saul

    saul Junior Member

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    if you try locking the prius you are not able if the engine is not shut off
     
  3. stevemcelroy

    stevemcelroy Active Member

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    For 100+ years cars have had to be turned off by the driver. In the Prius Toyota created a car that is pretty different than those that proceeded it. They went out of their way to keep it working like all of the other cars out there when they did not have to. One example is the slow creep that the car has in drive - the Prius transmission does not need to do this, but they made it do this so it was not different than all other cars. To me this is a good move.

    There is no clean way to do this in a way that makes 100% of owners happy, but I'd bet that the lions share want their car to work the way that all others do - in this case if the driver wants the car off, then turn it off.
     
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  4. bisco

    bisco cookie crumbler

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    it's a good idea, discussed many times here at p/c. it's just a question of how it can be accomplished. apparently, toyota hasn't been able to figure anything out in 10 years. the tesla seat switch sounds good and cheap, not sure why toyota doesn't employ it.
     
  5. stevemcelroy

    stevemcelroy Active Member

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    It adds a level of complexity that might not be cost effective in a car that starts in the 20s compared to a car in the 60s. The more important difference though is with the power train. If that switch fails in an EV you just loose range until the car runs out of juice. A failure of a similar switch in a hybrid keeps the gas engine running and opens up a whole world of liability issues with carbon monoxide poisoning.
     
  6. bisco

    bisco cookie crumbler

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    the switch would only work if the fob was in range. if it failed, the car would not start. as for complexity, i have one on my lawn tractor. but admittedly, i could be missing something here.
     
  7. cwerdna

    cwerdna Senior Member

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    The Model S starts at ~$70K.

    Their use of a "butt sensor" has caused other issues too. Shifts to Park when Butt Lifted from Seat? was a thread I remember seeing.
     
  8. bisco

    bisco cookie crumbler

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    ya, my lawn tractor seat is spring loaded. more difficult with a car seat.:cool:
     
  9. stevemcelroy

    stevemcelroy Active Member

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    I did not realize that lawn tractors have key fobs and push button starting. Just kidding, but the issue is a bit more complicated than just wiring a switch into the seat - and that is really what it is on a tractor - it would need to be far more complex to interface with the Prius or any modern car. Also, a lawn tractor has very different regulation, testing and liability issues than a car.
     
  10. bisco

    bisco cookie crumbler

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    checked out the tesla link, seems like a non issue.
     
  11. cwerdna

    cwerdna Senior Member

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    Non-issue? It seems like they had to do a bunch of tweaks like per Shifts to Park when Butt Lifted from Seat? - Page 9.

    Shifts to Park when Butt Lifted from Seat? - Page 10 is an example of someone who was able to repro.

    I haven't followed the chronology of this issue closely as I don't care that much. I'm sure this has been discussed in other threads there. Try Googling for site:teslamotorsclub.com butt sensor lifting.
     
  12. Matt Hirn

    Matt Hirn Junior Member

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    Thanks Saul! Yeah, that was discussed. I will definitely develop the habit of locking up with the fob. Discussing this characteristic was very helpful to me to make me be more cognizant of what I am doing when I get behind the wheel. In no time at all it will all be second nature. I am already loving the fact that the Prius is such a technologically advanced car.
     
  13. Matt Hirn

    Matt Hirn Junior Member

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    I would suppose that the liability of adding a back-up power down option to act as an added measure of protection is similar to the liability of the existing configuration. If someone leaves the Prius on unintentionally and something bad happens they may sue Toyota for not making it as safe as typical cars due to the silence of the car at rest. It seems similar to me in some ways to the addition of the first air bags on cars. You could choose not to use the seat belt or forget to use it and the air bag was still going to deploy in a head on collision as a secondary safety system. The air bags were probably much better than nothing at all. The fact that they could fail did not keep them from being added to supplement seat belts. Today it is nearly impossible not to buckle your seat belt. A warning chime rings incessantly and a warning light flashes until you fix the safety problem. My Dodge Grand Caravan turns on the flashers every time a sliding door is opened. Drivers may not notice an open sliding door and minivans frequently have impulsive children in them who hop out without looking. It is your responsibility to exit the vehicle safely, but it sure is nice to see that Dodge thought to add this touch along with a red reflective strip on the rear inner frame of the sliding door.

    Toyota could easily just use the on-board programming to register a driver seat pressure switch at power up and look for an open switch after the vehicle is in park. They could actually use the existing driver door switch in this same manner. It wouldn't even have to be an auto off feature. It could continuously sound the door lock beep sound over and over, flash the emergency lights for maybe five seconds and post a message on the dash display indicating that the vehicle was left in ready mode with no driver present and to press the power switch to turn the vehicle off. Although this would be annoying to delivery drivers who are in and out a lot, it would not shut the vehicle off on them while still adding a margin of safety.
     
  14. cwerdna

    cwerdna Senior Member

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    ^^^
    The above would be very annoying to those wanting to use their Prius as an emergency generator that was pointed out early on.

    You already should have audible and visual warnings if you exit and close the door (w/key on you) while in READY mode. My Gen 2 does and IIRC, the Gen 3 does too. And, it should refuse to lock the door from the outside while in READY w/audible warnings.
     
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  15. Matt Hirn

    Matt Hirn Junior Member

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    Thanks. You are correct. I just noticed that three beeps are provided when exiting with the car in ready mode. I was under the impression that the three beeps only happened when using the fob to lock it. I did not notice the visual cue that you mentioned. Being an assistive technology specialist, I would love to see the beep ramped up to a more noticeable six beeps going in cadence with the flashers for six flashes to aid those who are hearing impaired. Just a thought.

    Thanks again for the added insight. Obviously, design engineers can't please everyone.
     
  16. cwerdna

    cwerdna Senior Member

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    ^^^
    I believe you might either see a light or a message on the dash (beside the instruments being all on).

    Also, when you try to lock it by pushing on the ridges, IIRC, it should refuse to lock and emit a long beep.

    As an aside, my mom's Altima Hybrid w/Intelligent Key (Nissan parlance for Smart Key System) does not have very loud equivalent warnings. They're softer than on my Gen 2 Prius. It also lets you lock the car by pushing on the lock button on the door handle even when the car is in READY mode. I tried that.
     
  17. bathala

    bathala Member

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    Auto off sounds like a nice feature to have. Has anyone sent a letter to Toyota recommending this feature? Curious to know how they would respond. Good day everyone!
     
  18. cwerdna

    cwerdna Senior Member

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    Maybe you and/or the OP should? But please consider all the scenarios outlined here and the problems adding the behavior would create besides extra points of failure. If they were to implement it, think about the precedent that it would set as well as behaving differently than all previous models.

    This isn't the first time this topic has come up.
     
  19. bathala

    bathala Member

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    I read and understood the concerns and the complexities for having this feature. No, I do not agree that I should aend the letter since first I did not say it's easy for the manufacturer to build and second I do not know how to make it work. I just want to know if someone had thought about bringing this idea to Toyota. :)
     
  20. szgabor

    szgabor Active Member

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    So let say just by accident you or your wife gets out of the car with the key in the pocket, you drive away and 10 minutes later the car just cuts off power on the freeway ... would you be happy ???

    Did not think so .. but if you the driver stops (safely) turn off the car .. NOW without the key you can not start... seem pretty safe to me ...

    Just sayin.....

    welcome to prius !!!