NHTSA Tracking Braking Loss on Prius Hybrids

Discussion in 'Gen 3 Prius Main Forum' started by RobertMBecker, Dec 24, 2009.

  1. bestmapman

    bestmapman 04, 07 ,08, 09, 10 and 16 Pri

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    I have never experienced anything at all close to this. I do not believe that a LOUD AUDIBLE BANG that would make my passenger believe that we were hit, is a normal occurance.

    This is a major problem and you should not drive the car and have it towed to the dealer for service.

    [added:] Any noise that is so loud that you would think that you have been hit is call for immediate service. I think that this is now a safety and liability issue for you. Now that you have identified there is a major problem with your vehicle. Please do not drive it. You will be endangering yourself and others.
     
  2. rrolff

    rrolff Prius Surgeon

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    This is something I directly remember from one of my experiences.

    It was on a dry surface at around 10-15MPH, I was turning into a parking lot, there was a gutter (slight - no real bump).

    Weird thing is when the 'event' happened, I distinctly remember hearing an audible 'pop' - not a bang, but more the sound of like a rock in the wheel well/hitting the side of the car (on the other side of the car). This happened at the instant the brakes faded. The street was clear, and there were no rocks or anything else around.
     
  3. bwilson4web

    bwilson4web i3 and Prime

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    Thanks! This makes a lot more sense. I went 'North' but only a mile or so looking for the next light. I noticed the road was looking more and more ratty (kind of a seedy looking area but many light industrial areas come across that way.)

    I'll go back and 'drive' a couple of miles North and see what I find. Please don't worry about absolute precision ... we can adjust:

    There were plenty of street repair patch jobs and it is not uncommon that between the Google Street View survey and your recent experience, something changed. Please be patient with us.

    The noise is something interesting but sounds as if it is recent. If it is reproducible, we may have something.

    Bob Wilson
     
  4. rachaelseven

    rachaelseven New Member

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    I believe it was your first one there. Here it is with a slight tweak... tar patch across the width of the lane, about a foot wide, not a pavement joint as I first reported:

    Route 7, - Google Maps

    I was in the left lane (straight on, not right turn) and to the best of my knowledge I did not cross the manhole cover, although I wouldn't swear to the avoidance of the manhole.

    Regarding the other comments, the bang sound is not at all reproducible - it is quite rare in fact - and although it sounds like great cause for concern, it is really just the rear brake grabbing or ungrabbing suddenly and is no more problematic than than the change in braking. Concern is of course appreciated and I will note it with the dealer, but it is not sufficient to render the car unsafe or require towing. It is just another artifact of whatever this calibration quirk is.

    P.S. - Yes, it is definitely a lower income area with poor road maintenance. 'Seedy' is certainly an apt description, although I will qualify that by saying that I use the word without passing judgment on the inhabitants.
     
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  5. rachaelseven

    rachaelseven New Member

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    I would not suggest it is a normal occurrence - that is why we are discussing it in the context of a problem. But perhaps I did not communicate it well enough... the noise combined with change in brake force left the impression of getting 'tapped' from behind, like if the offender was going 5mph, not a 'bang' like someone just wiped the whole front end off their car on my back bumper. I should have used clearer adjectives - my apologies if I caused alarm. As I said above, the noise is rare, and although startling, is no more sign of a serious problem than the behavior of the brakes themselves. It is an issue and it does need to be fixed, but it is really not the 'pull the car over and have it towed' type of thing. Really it isn't, the brakes work fine - there is just this quirk under certain conditions of slip when the ABS activates (probably prematurely, imo). And unless/until I find a place where it can be easily, consistently, and safely reproduced, there is just no point in taking it in since the dealer won't find a problem anyway. For now, I'm content to continue researching the precise nature of the problem so that I can present the dealer with a clear enough case that they might be able to do something about it.
     
  6. Kenc

    Kenc New Member

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    I just made my complaint to NHTSA through its website at [email protected][email protected]. I recently bought a 2010 Toyota Prius and it has a cutting brake/sudden acceleration type problem when I drive over rough pavement. This may be a serious safety issue. I recommend everyone file a complaint with NHTSA. You owe it to yourself and others!! I think NHTSA will open an investigation if enough people file complaints. This is not a floor mat or sticking pedal type problem in my opinion - there is some sort of electronic glitch causing this problem.
     
  7. Kenc

    Kenc New Member

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    Mistake in previous message - make the NHTSA complaint through the following:

    [email protected]v

    VERY IMPORTANT TO MAKE THE COMPLAINT IMMEDIATELY SO NHTSA OPENS UP AN INVESTIGATION!!!

    THIS COULD BE A VERY SERIOUS SAFETY ISSUE - YOU OWE IT TO YOURSELF AND OTHERS!!!
     
  8. hockeydad

    hockeydad New Member

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    Ken,

    I noticed that you have 7 posts on this web site, and they basically all read the same. OK, we got that you are concerned, but isn't that a bit excessive? Further, why do you "recommend everyone file a complaint with NHTSA"? Many on here, in fact, probably most have not experienced what you describe. So why should we file a complaint? Wouldn't that fall under the heading of lying/perjury?:cool: I hope that's not what you are asking people to do - ie, file a false (or exaggerated) complaint? I'm sure that's not what you intended, but thought you might want to set the record straight. To be clear - I'm NOT suggesting that people not file their concerns/complaints. But I do believe the complaints will have more merit and validity if substantiated with facts, and frequency of occurance.


    I've been following this situation very closely, and here is my assessment -

    I have over 7K miles on my G3, and have had no problems with acceleration. However, a few (on this site - including once by your's truely) have reported that under very specific conditions during regenerative braking, a feeling of temporary (sub-1 second) loss of braking can occur. Some have described this as a "sudden surge, or lurching", but more likely what they are feeling is a change in momentum. Last time I checked, there have been about 30 complaints (out of about 130,00 Prius sold last year) to the NHTSA. But now, with all the hysteria being whipped up by the Detroit press (and others), I have no doubt there are more complaints - real, imagined or falsified. To my knowledge, no accidents have been reported. This phenomena does seem to be asociated with the regenertive braking on the Prius, and owners of older versions of the Prius have (also) reported a similar phenomena. But with all this said, and given that this problem has been around well before the G3 got here, no determination has ever been made on whether there really is a problem, or whether this feeling, is just that - a unique and unfamiliar feeling that is associated with regenertive braking. In fact, I don't believe there's ever been an investigation by the NHTSA regarding this issue - yet G2 owners have reported this? As for my own experience, it was once, and the sensation lasted less than a second...and it felt like the braking force had been reduced. Those that have reported this sensation (more than once) have noted that when they press down harder on the brakes, and transition into the conventional frictional braking, the sensation goes away.

    So the question I ask - If this sensation has existed for many years (ie going back to the intro of the G2), why has there never been a formal investigation? Has the problem gotten more severe with the G3, or, have drivers that first experienced this sensation now become familiar with the sensation and don't think it's a problem - they just push down a bit harder on the brake pedal? Are the majority of reports of this phenomena, made by newbie/virgin Prius owners...or by seasoned vetrans of driving a car with regenerative braking? I don't have the answers, but I do find it odd that G2 owners have mentioned this and it's never gone anywhere? A Toyota cover-up, or drivers just becoming more comfortable with a new sensation? I'm sure those in detroit, and their affiliates would love for Americans to believe this is one big cover-up by the "Nips" (as one jingoistic Detroit poster put it). Finally, are people in Japan, Europe and other nations where the Prius is being sold also reporting (with similar frequencies) the same issue....or is it just in the US that this phenomena is happening? Don't know? But I do know a lot can be learned ny looking at all these corellations before jumping to any conclsuions.

    Right now, there is sooooo much hype and hysteria going on, it's very hard to pull out truth, from hysteria, and to what degree any of these problems are - ie if the brakes are in fact failing, does temporary brake failure happen in 1 out of every 100,000 cars or is the frequency of occurance much less/more? If the frequency of occurance is significant, then that's when I get worried, but if the chances are small, then I don't worry. After all, we can assign a probablity to every life event, e.g., 1 out of every 10,000 people will develop some form of cancer, etc...probability that your tire will blow out going at highway speeds is 1 in a million. But everything has a likelihood. It's all about probabilities, and no car is perfect.

    This driver is not prepared to file any compaint, as I'm not convinced that there is a real problem, but rather, it's a different sensation because of the transition from regenerative to frictional braking. After I've driven the car, and this happens multiple times and pushing down on the brakes harder does not do anythng...then I file a complaint.
     
  9. bestmapman

    bestmapman 04, 07 ,08, 09, 10 and 16 Pri

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    Here we go again, a low post count person with outlandish claims. I am one of those who can't seem to get it to do it. This poster obviously has an agenda.
     
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  10. PriusSport

    PriusSport senior member

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    I went over a couple of rough spots on the road the other night in construction areas (which never seems to end), and the vehicle stability light (under the "ready" light) flashed just briefly, and then went away. First time I had seen that. The book says not to be concerned. Really a sign things are working OK when a wheel gets jiggled.

    I have never had a problem with the brakes, which seem fine.
     
  11. Airbalancer

    Airbalancer Active Member

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    I drive 3 different vehicules in our house
    2000- 323 BMW CIC, 2003 GMC 4x4 extended cab and a 2010 Prius
    Each braking system has a different feel, you have learn each car
    No big deal
    Maybe the really problem is it could be to easy to get a drivers license
     
  12. bestmapman

    bestmapman 04, 07 ,08, 09, 10 and 16 Pri

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    If you think the car is so dangerous, then why are you still driving it.

    STOP DRIVING IT and have it towed to the dealer.
     
  13. hockeydad

    hockeydad New Member

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    Hard to tell whether markc has an "agenda", or whether he's just one of those people that gets scared at everything, and takes the mentality that "the sky is falling". I suspect he falls into one of these two categories. Regardless, he certainly has the right to file a complaint if he feels there is a flaw with the car. I have no problem with that. But I draw the line when posters, like marc, try to further whip up the hysteria by encouraging, "everone to file a complaint to the NHTSA". Sounds like he's trying to encourge even those that have not experienced this phenomena to file a false complaint? All these recalls have basically opened the flood-gates to mob hysteria - which will then bring in everything from people with genuine complaints, to those filing false reports that furthers their agenda. After reading many of the posts on the Detroit Free press, and the venom they spewed forth, makes me 100% certain that some percentage of these claims (on Toyota in general, and not Prius specifically), are completely false. Make no mistake, there is a LOT at stake here - both in peoples lives and corportate $$$ (both Toyota's and Detroit's). Detroit, and friends of Detroit, have a lot to gain from Toyota's downfall, or embarassments.


    To newbies like Marc who tell us that "everyone" should report this to the NHTSA, I say (from an earlier post) -

    The question I ask - If this sensation has existed for many years (ie going back to the intro of the G2), why has there never been a formal investigation? Has the problem gotten more severe with the G3, or, have drivers that first experienced this sensation now become familiar with the sensation and don't think it's a problem - they just push down a bit harder on the brake pedal? Are the majority of reports of this phenomena, made by newbie/virgin Prius owners...or by seasoned vetrans of driving a car with regenerative braking? I don't have the answers, but I do find it odd that G2 owners have mentioned this before and it's never gone anywhere? A Toyota cover-up, or drivers just becoming more comfortable with a new sensation? I'm sure those in detroit, and their affiliates would love for Americans to believe this is one big cover-up by the "Nips" (as one jingoistic Detroit poster put it). Finally, are people in Japan, Europe and other nations, where the Prius is also being sold reporting (with similar frequencies) the same issue??....or is it just an American phenomena? Don't know? But I do know a lot can be learned ny looking at all these corellations before jumping to any conclusions.

    There is sooooo much hype and hysteria going on right now, it's very hard to pull out truth, from hysteria, and even the false allegations. To what degree is there a problem? - ie if the brakes are in fact failing, does temporary brake failure happen in 1 out of every 100,000 cars, or is the frequency of occurance much less/more? If the frequency of occurance is significant, then that's when I get worried, but if the chances are small, then I don't worry. After all, we can assign a probablity to every event in life itself, e.g., 1 out of every 10,000 people will develop some form of cancer, probability that your tire will blow out going at highway speeds is 1 in a million, probability you or someone in your family will experience a violent crime is 1 in 50,000, etc, etc. Everything has a likelihood. It's all about probabilities, and no car is perfect...including the Prius.


    This driver/poster is not prepared to file any compaint, as I'm not convinced that there is a real problem, but rather, it's a different sensation because of the transition from regenerative to frictional braking. But even if there is a real problem (not just a sensation), then is there a significant probability that my car could be affected...or is it a 1 in a million chance? After I've driven the car for enough miles that i can make a fair assessment, and should this phenomena happen multiple times... and pushing down on the brakes harder does not do anythng...then that's when I file a complaint. That's when I get concerned. But not before.
     
  14. p626808

    p626808 New Member

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    I went thru most of the 40+ pages in this post, and I will throw my 2 cents in.
    I have 15K on my 2010 V.

    I have had this problem happen on several occations. both high speed and low.
    It is quite scary when it does happen, especially at high speeds. It does feel like you lose control for a split second.
    But.. I have come to recognize it and make appropriate brake pressure adjustments, so I don't get in trouble.

    I had a 2004 before my 2010 that had 190K miles on it.
    Something similar happened with it.. but not as bad as my 2010.

    I think it needs to be looked at by toyota. but, considering there accelation issues they are dealing with now.. this is not a priority.

    Scott
     
  15. Chaz

    Chaz Junior Member

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    Excellent post! After reading a ton of these today it's nice to see someone with some common sense. I have had this happen too around 20+ times and I was flamed in another thread. Besides this issue, I'm very happy with my Prius after 9K+ miles! Thanks!
     
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  16. wvgasguy

    wvgasguy New Member

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  17. wvgasguy

    wvgasguy New Member

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  18. wvgasguy

    wvgasguy New Member

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  19. bac

    bac Active Member

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    Ding ding - we have a winner!

    -Brad
     
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