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Braking problem

Discussion in 'Gen 3 Prius Main Forum' started by eglmainz, Jun 22, 2009.

  1. Paradox

    Paradox Prius Enthusiast / Moderator
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    Re: Acceleration Surge Going Over Bump

    Is the surge while braking over a bump? That has been noted and talked about on here many times over. It's not a surge of power if it happens while braking, but a short coasting sensation while the system transfers over from regen braking to friction braking.

    If the surge of power comes while your foot is simply on the gas, you're probably pressing down more while hitting the bumps and not realizing it. I find it near impossible (and have never heard of this) for the car to accelerate on its own while just driving.
     
  2. spiderman

    spiderman wretched

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    Re: Acceleration Surge Going Over Bump

    If you are coasting (no gas pedal applied), you might be experiencing loss of regenerative braking when the computer "feels" the bump and disengages. Just a guess.
     
  3. qbee42

    qbee42 My other car is a boat

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    Re: Acceleration Surge Going Over Bump

    Yes, really. There are many threads dealing with "acceleration" over bumps while braking, but the OP makes no mention of braking.

    In this situation, it's most likely inertial effects causing the driver's foot to momentarily press harder.

    Tom
     
  4. hockeydad

    hockeydad New Member

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    Re: Acceleration Surge Going Over Bump


    Tom,

    I was being sarcastic about his question of - "has anybody experienced this before"?

    As in - Is this "really" a question? You "really" did bother to look before posting? Evidently not.

    If you've seen some of my prior posts on this subject, I'm actively following the hysteria...personally, not convinced it's anything more than a (unique) sensation found in cars with regenerative braking. But unlike some of the hysterical people on here, I'm willing to try and gather more information before passing judgement as to whether this is a serious problem, or not.
     
  5. hockeydad

    hockeydad New Member

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    Re: Acceleration Surge Going Over Bump

    What's a bit suspicious to me is - the vast majority of posters who start a new thread on this subject (even though there are already quite a few), are usually posters with only 1 post. Newbies with a legitimate concern, or trollers? :confused: Take a look at the detroit free press, or in regions of the country where GM and Ford are king, and the frenzy you will see is analogous to Fox News after the republicans captured Kenedy's Senate seat a few weeks ago. Utter frenzie.
     
  6. Chaz

    Chaz Junior Member

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    Has happened to me many times, got my 2010 in Sept. Dealer said they don't know about it so I didn't waste my time going there.

     
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  7. hockeydad

    hockeydad New Member

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    Ah, yet another 1st time poster with his experience to share. Why am I not surprised. :rain:
    A clear pattern is beginning to emerge, and I smell a skunk.. :rolleyes:

    If it has happened "many times", as you describe, then one would think you could reproduce this phenomena in a test driver for the service rep? Unless you can reproduce, why would you expect the service dept to fix a problem they can't make happen? Are they suppose to be magicians? What was your complaint, again?

    I have over 7K miles on my G3 and have had this "sensation" exactly once, for about the length of a blink of an eye. It did catch me off guard, so now i apply more pressure to the brakes when going over bumpy surfaces. So far, have not had this sensation again. Is there a genuine flaw in the braking system, or is this simply a unique feeling to cars like the G3 with regenerative braking? Don't lnow. But I do know that pleanty of G2 owners have said they've felt this phenomena, so we know it's been around for quite a while. Any investigations on this issue? Not that I am aware of...so do the complaints subside once new owners of these types of cars get use to the feel of this type of braking. Since no investigation (so far), I suspect that they do.
     
  8. Chaz

    Chaz Junior Member

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    done;
     
  9. Chaz

    Chaz Junior Member

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    Why so negative? Yes I can reproduce and I have the spots in the local area where it occurs. I called them to see if any one else was reporting yet. I won't make a seperate trip, but next oil change they can check it out. Geez:D
     
  10. hockeydad

    hockeydad New Member

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    Geez....Let's see:

    - It "happens all the time".

    - Apparently is enough of a safety issue (to YOU) that you filed a formal complaint with
    the NHTSA, ie "done".

    - Now you say (essentially), no rush, I'll have them look at it when i take it in for "the next
    oil change". Sure sounds like an after-thought to me?


    I suspect that most people, if they could reproduce this on a regular basis, would be in the next available day to have it checked out. So which is it - Not really enough of a concern/worry of your's, or you really can't reproduce it?

    Be sure to tell us what they said. :rolleyes: LOL. I'll save you the trouble - "they can't reproduce it", or, "it's normal". $20 says that's the response.
     
  11. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Then share the Google addresses of these spots.

    Thanks,
    Bob Wilson
     
  12. The Electric Me

    The Electric Me Go Speed Go!

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    Re: Acceleration Surge Going Over Bump

    You are in danger of being mistrusted and ridiculed for saying you can find no reference to this problem within Prius Chat. Look a little deeper there are many threads, posts describing almost exactly your problem. It does have a history.

    The research, the debate as to the definition, and/or how people should react to it, is wide ranging and hotly debated. In general it is accepted to be the split second transference when the system goes from regenerative to friction braking. But the exact reasons, the exact definition as to problem, solution and driver/owner reaction is still up in the air.
     
  13. Chaz

    Chaz Junior Member

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    Roll your eyes all you want :) I like the car and I'm not asking for them to replace or repair anything, or making demands to the dealer. As I said, just asking if anyone reported it and I will do the same. I guess if they were as *knowledgeable* as you they could have explained the reason why it occurs..LOL. Many times to me in 9000 miles was around 25 times, a few right at an intersection, so that 4-6 inches where the car "takes off" is not good. Yes I'll spread the word on findings on here and FB. ...or maybe your statistical sampling of one time in 7K should be what Toyota uses as their baseline..LOL You admit it occurred, so why is not possible that it may occur more in the snow belt or other areas with crappy roads for example?

     
  14. hockeydad

    hockeydad New Member

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    Nice rant, but you didn't answer the questions. :rolleyes: So which is it - Not really enough of a concern/worry of your's, or you really can't reproduce it? Also, don't forget to give bob your data on locations.


    WHAT (????), you're "not asking for them to replace or repair anything, or making demands to the dealer." :eek: :eek: Ummm, why NOT??? If there's a problem, and apparently it's a safety concern to YOU, and the car is under warrenty, why wouldn't you ask for a repair, or to thoroughly check out your vehicle?? Fact is, your story simply doesn't hold water and is inconsistent...and the aformentioned statement of your's is just further proof of this.

    As far as "just asking if anyone reported it and I will do the same." ...if it's a concern of your's, why do you care if anyone else has reported it? Just report it, which, in a prior post, you alleged to have already reported it...but now say, "I will do".


    Finally, you say: "You admit it occurred, so why is not possible that it may occur more in the snow belt or other areas with crappy roads for example?" Obviously, you've never driven in Baltimore. LOL. Pick your east Coast city, and they have crappy, pot-hole laden roads - big time. But I suspect that it has not occured more than once for me, because ever since it happened, I now apply more pressure when braking...
     
  15. spinkao

    spinkao New Member

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    Re: Acceleration Surge Going Over Bump

    If you re-read his original post, his problem does *not* occur under braking. I was also thinking that he was experiencing the "normal" momentarily loss of braking power, but it does not seem to be the case. He sais "it makes him to hit the brakes", so I assume he was not braking at the moment it happened.

    And yes, I was also thinking about a troll, but I am not going to falsely accuse anybody of trolling without evidence. He might really be a first-time poster with a real problem.
     
  16. Chaz

    Chaz Junior Member

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    Then maybe they will educate the salespeople to let them know about the "normal" behavior. :)
     
  17. mad-dog-one

    mad-dog-one Prius Enthusiast

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    Re: Acceleration Surge Going Over Bump

    Your claim of objectivity (not passing judgement) is inconsistent with your conclusion that others are histrionic (hysteria). Your sarcasm, lack of internal consistency in your statements, and attack of others perturbs objective, evidence-based evaluation of this question. No one cares about your opinion or spin; we care about the evidence. Consider the advice of Sgt. Friday when gathering evidence; "just the facts Ma'am."
     
  18. Chaz

    Chaz Junior Member

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    Bob, sure, I have a few trips planned this week and I will record the exact spots. Thanks!

     
  19. finman

    finman Senior Member

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    Re: Acceleration Surge Going Over Bump

    thanks hockeydad. great post. hysteria seems to be rampant in all facets of our society.
     
  20. hockeydad

    hockeydad New Member

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    LMAO. :D :D This makes zero sense. None. All I can say is, WOW! Great justification. :eek:

    You claim that (1) This happens to you on a regular basis. You apparently are concerned enough about the safety aspects of this that you (2) have, or "wiil do" a formal complaint to the NHTSA, and (3) will not ask the service department for a repair or to replace a defective component even though the car is under warranty!?

    Your interest in reporting it to your dealership is so that (1) the salespeople will be "better informed" and to let other customers know about this issue?

    Now this is too funny. :D But whatever, man. Good luck. ;)