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Hill Start Assist Activating at every stop

Discussion in 'Prius c Care, Maintenance and Troubleshooting' started by sfruski, Nov 10, 2014.

  1. sfruski

    sfruski New Member

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    I just purchased a 2014 Prius C and am having a problem with the Hill Start Assist/Control. At every single stop, no matter how lightly I press the brake, when I release the brake the car stays in place for two seconds (no gas), and then starts moving.

    I am assuming this is the HSC and not a normal function on the car.

    If I depress the brake all the way no lights come on, no buzzer sounds, but the above described behavior still happens. I've tried the light stops on up hills, down hills, and flat ground, it all is the same.

    I'm in the process of taking it into the dealer, but does anyone have any ideas?
     
  2. sfruski

    sfruski New Member

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    I drove the car a bit more around tonight and the traction control light cam on and is staying on. I'll get that appointment at the dealership...

    On the plus side, with the traction control light on, hill assist isn't turning on every time I bring the car to a stop.
     
  3. Easy Rider 2

    Easy Rider 2 Senior Member

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    I think mine does something similar but not sure.
    Even if it DOES, why is that a problem ?
     
  4. sfruski

    sfruski New Member

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    It makes driving the car in slow precise situation very difficult, for example parallel parking. Also it does not appear to be how the feature is suppose to be working, possibly pointing to a larger issue.
     
  5. bisco

    bisco cookie crumbler

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    mine never does it, unless it's common to the c, i would get it fixed. not sure if it's mechanical or computer.
     
  6. Easy Rider 2

    Easy Rider 2 Senior Member

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    One big potential problem I see here is you assuming that this behavior is because of the "hill hold feature" when it might not be.

    The "electric creep" is artificially added to make it "feel" more like a conventional car with automatic transmission.
    The basic design means that at a stop on flat ground the ICE would be off and the electric motors would be inactive and the vehicle would not move.
    The extra creep is added on purpose.

    If you do take it in to have it checked out, tell them the SYMPTOMS only; try to resist also offering them an analysis of why it is happening. :)
     
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  7. bisco

    bisco cookie crumbler

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    how are you relating the creep feature to the car not moving for 2 seconds after releasing the brake?
     
  8. Easy Rider 2

    Easy Rider 2 Senior Member

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    That **IS** the creep feature.

    Whenever your foot is off the brake, the car moves slightly......or tries to.

    In my C, I'm pretty sure there is no noticeable delay but I'm not sure I would notice it if there was.

    If there is a noticeable delay, it could be several things but the most obvious, I think, would be a brake dragging slightly.
     
  9. bisco

    bisco cookie crumbler

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    ya, no delay in any of my pri, so it's probably not normal. i will say, the creep is so aggressive, it can make moving short distances like parallel parking very jerky.
     
  10. Tideland Prius

    Tideland Prius Moderator of the North
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    I take it you never activated the Hill Start Assist on your PiP? (Depress all the way down until you hear a beep and a flashing VSC light)
     
  11. bisco

    bisco cookie crumbler

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    yes, i have. i'm just not understanding the relationship. HSA, keeps the car from rolling backwards on a steep hill when you transfer your foot from the brake to the gas. the creep feature moves the car on flat ground when you take your foot off the brake. how are they related?
     
  12. Easy Rider 2

    Easy Rider 2 Senior Member

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    They are NOT......normally.

    I think he might be blaming the "hill hold feature" when it is NOT the culprit and the problem instead is with the "electric creep" feature......if indeed there is a problem at all.

    Get it now ??
     
  13. bisco

    bisco cookie crumbler

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    i get what you're saying. i don't get how they could be confused, they are completely opposite.
     
  14. The Electric Me

    The Electric Me Go Speed Go!

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    Sometimes I approach the diagnosis of mechanical problems, similarly to medical problems.

    Long story short, I have family members that are doctors, and for various reasons I would say I have collected more "medical" knowledge than most people on the street. Although I am not a doctor.

    Therefore I would agree with the advice concerning giving ONLY the symptoms and withholding any conclusive diagnosis when presenting the vehicle for service. I have to do this myself with both doctors and mechanics.

    The risk or danger in not witholding doing so, that I have found is often a mechanic or doctor...is far too ready to accept your diagnosis of the problem. If you're not a mechanic or not a doctor? This can be dangerous. In other words, I always assume I might be wrong, despite any extra knowledge or insight I think I might have to the problem. I let them come to me, and tell me what they think the problem is...

    If I disagree with their conclusions? I'll debate it with them at that point.

    In this case my pure internet speculation is that the OP obviously has a problem with the "Stop and Start" behavior of his vehicle. This is manifesting with the Traction Control Light being activated, which just could mean a LOT of things. Is it a problem with specifically Hill Start? Is it a problem with the whole system?

    I don't know...but I'd want them looking at EVERYTHING it could be...therefore I would not volunteer any opinion that it might only be a problem with Hill Start Assist, although I would offer what it was doing and is doing now, as symptoms of the problem.
     
  15. bisco

    bisco cookie crumbler

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    is the HSA a switch on the brake pedal like the brake lights?
     
  16. robertmaria

    robertmaria Member

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    the brakes are very grabby on my Prius c at low speed. my HillStartAssist doesnt BEEP and rarely lights the light, but it does engage because when i release the brake it holds the car if i pushed the brakes down hard enough. i think the ECU has different programming on certain c models. it certainly is different from what the manual says.
     
    #16 robertmaria, Nov 11, 2014
    Last edited: Nov 12, 2014
  17. bisco

    bisco cookie crumbler

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    sounds exactly like my pip, and all my pri have had grabby brakes.
     
    #17 bisco, Nov 12, 2014
    Last edited: Nov 12, 2014
  18. ztanos

    ztanos All-around Geek!

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    The brakes are grabby on mine, but the hill assist doesn't engage unless I mash the pedal to the floor for a couple of seconds.
     
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  19. bisco

    bisco cookie crumbler

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    same here.:)
     
  20. dig4dirt

    dig4dirt MoonGlow

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    I have the same going on with my 2014 prius C

    I had a 2012 C that I traded in for the 2014 C

    It is very noticeable when I stop on slight inclines. I was used to the 2012 rolling back just slightly,
    but the 2014 will not. And I am not activating the hill assist.
    It is not causing any problems by my, but it is kinda annoying, as I am not used to yet.

    I only parallel parked once, but I didnt notice.
    Only time i notice is when stopping on a hill.