Toyota's Next PR Nightmare: Prius Brakes

Discussion in 'Prius, Hybrid, EV and Alt-Fuel News' started by Danny, Feb 3, 2010.

  1. Danny

    Danny Admin/Founder
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    Things seem to be piling up on Toyota lately, and a day can't seem to go by without new allegations of safety concerns in Toyota's vehicles. Last week Toyota found themselves in "Recall Hell" and yesterday they were sucked into a media vortex over Steve Wozniak's questionable issues with the Prius' cruise control. The next problem on the horizon? Prius braking issues. The AP and just about every other news publication in the world are reporting that Toyota has been hit by over 100 complaints in the US and Japan about brake problems with the Prius hybrid. 14 of those complaints are from Japan. PriusChat member ken1784 posted that Toyota already modified the computer program of Prius brake ECU to improve the brake system since January production. Most of the problems appear to result from the Vehicle Stability Control feature on the Prius. When the Prius hits a patch of uneven pavement or is taking a sharp turn while lightly braking, the Prius' brake ECU interprets that as a situation where the computer needs to step in and keep the wheels from locking up. Most of the time this leads to a very scared feeling and perhaps even a need to change your underwear, but if you stay on the brake it autocorrects and things end up OK. The problem has been VERY widely reported in the PriusChat forums for years with the 2nd generation, and over 6 months with the 3rd Generation Prius. Here's a selection of some of the very large threads: NHTSA Tracking Braking Loss on Prius Hybrid Braking problem Whether it's a problem with the way the ECU is programmed or just a problem with customer education, this is another example of Steve Wozniak's core argument: It's hard to get a company like Toyota's attention unless something drastic happens, or in this case, if every news cycle can't go by without a new Toyota "problem story".
     
  2. paprius4030

    paprius4030 My first Prius

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    :violin:My Gen.2 does the same damn thing. Big deal get used to it. The government rammed this anti-lock brakes bull down our throats. I know how to drive and don't want anti-lock brakes and VSC anyway. People should learn how to drive and not relie on all this expensive BS. That's my 2 cents LOL
     
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  3. usbseawolf2000

    usbseawolf2000 HSD PhD

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  4. Taran

    Taran New Member

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    Wow. So, you'd rather the vehicles be less safe and to not work properly? Regardless of how you feel about others driving ability, malfunctioning breaks or VSC is hardly user error or something to scoff at.

    I'm almost speechless at the sentiment expressed here.
     
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  5. paprius4030

    paprius4030 My first Prius

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    My point is these devices ARE working properly but they cause unintended consquences. Like the brakes letting up when your going across a rough surface ect.
     
  6. SyCo

    SyCo Member

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    Malfunctioning :confused: It's designed that way !!

    My Gen 2 does that occasionnaly when that particular situation arise (uneven or slippery road + regen to mechanical break switch + ABS ) and I slimply apply a little more pressure to my brake pedal.

    The only reason it comes out into the media it's because new buyers of the 2010 Prius are also new to the hybrid world. They don't know that an hybrid add the "regen braking" into the equation.

    my 2 cents
    :)
     
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  7. David Beale

    David Beale Senior Member

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    From what I've read it's no different than the GII. I suspect this is just "piling on". "While we have Toyota on the ropes, what about -this-?"

    If you really believe the brakes will work when the wheel is in the air, then you have a point complaining.

    If the 1/2 second brake release might cause you to hit something, YOUR LEAVING YOUR BRAKING TOO LATE!

    Now in defense of the complainers, I keep wondering if it's the shock of the bump -on the chassis- that is triggering something. I wonder this because sometimes it doesn't seem the wheel would be hopping. But without measurements I can't tell and wouldn't be yelling at -whoever- about safety.
     
  8. efusco

    efusco Moderator Emeritus
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    And you'd rather be reactionary and live in fear based upon a handful of reports from new drivers who are unfamiliar with how the regenerative braking works and had a few unsettling sensations. The brakes are triple redundant and the loss of sensation is momentary and can be easily overcome with increased brake pressure and only occurs at slow to moderate speeds. There's no safety issue.

    Don't let the hysteria of the press influence your research of the facts.

    BTW, you might wanna review This Thread. The OP of that thread is the key source of the now rising hysteria. He got a friend who has a private little news page to post his story, then they managed to get a couple of MSM sources to pick that up, and now, in light of the acceleration issue it's now coming to congress as part of the piling on process. But if anyone had actually talked to experienced hybrid owners we could demonstrate what's occuring, explain it, and clear up the whole issue in about 10 minutes.
     
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  9. bestmapman

    bestmapman 04, 07 ,08, 09, 10, 16, 21 Prime

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    I do not know how you get "So, you'd rather the vehicles be less safe and to not work properly" out of this. a lot of people think there own driving ability is better then the VSC is to control the car.

    It is nice to see your wealth of experience and knowledge on here. It shows.
     
  10. DeadPhish

    DeadPhish Senior Member

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    After 142,000 miles on my 2005 I don't see anything as malfunctioning. I agree with the prior poster. The vehicle is different. It's just different. But it stops a lot better than any other vehicle I've ever driven so in that regard it's the best and there is no problem.


    A good friend has put...
    • 38,000 miles on his Gen 1
    • 246,500 miles on his Gen 2
    • 17,000 miles thus far on his Gen 3
    ...with no 'braking issues' at all - ever. Combined with my own personal experiences that's nearly half a million miles, 3 generations and 6 solid years of driving the Prius and neither of us has ever experienced anything like what the complaints allege. Some drivers might be having these experiences but AFAIK there is no malfunction or error. I do know one thing, no one is changing anything in my Prius. It works perfectly and I understand everything about it.
     
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  11. jburns

    jburns Senior Senior Member

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    I think its safe to say the truth lies somewhere between these two statements.
     
  12. jburns

    jburns Senior Senior Member

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    If that is the case Toyota, as an experienced hybrid builder, should have been able to clear it up in the same 10 minutes.
     
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  13. tpfun

    tpfun New Member

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    Your conclusion only holds water assuming any auto vehicle is safe at slow to moderate speeds.

    I would think a pedestrian involved with a low speed auto collision would disagree.
     
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  14. cshbell

    cshbell New Member

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    I understand the indignant reactions of experienced Prius drivers to this. I even agree to an extent, and believe me, I love my Prius as much as the rest of you. However, as a G2 owner, I've always felt that the power surge braking sensation was a bad design from the perspective of user experience. Some drivers react to this sensation incorrectly and maybe dangerously.

    You can certainly make the case that the car is behaving better than the driver; nonetheless, the driver is ultimately in control, and I feel the car's feedback should always be towards increasing the sense of control; ergo, further scrutiny of this may be warranted.
     
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  15. Tideland Prius

    Tideland Prius Moderator of the North
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    Just to pad paprius' response, there was a fellow here who claimed that VSC caused him to crash. Ultimately, we found that even though he was experienced in winter driving, he was not familiar with the VSC program and thus when he tried to apply his skill when the situation occurred, he ended up making things worse because the computer reacted faster than he did and in the end, he managed to go off the road.


    People need to learn the features of their cars. It doesn't matter if it's how to turn on the high beam or how the traction control works. Every car manufacturer is slightly different. It applies esp. to those who have been driving a particular brand for a long time (and thus accustomed to their design) and then switches brand.
     
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  16. austingreen

    austingreen Senior Member

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    Some statements are factual, and others are blatant lies. Often these lies start as opinions, that are reinforced and parroted, until those stating the opinions of others think they are facts. As evidence piles up, belief in these parroted opinions become more important than the facts. Half way between a lie, and the truth, is not the truth. Often people don't understand that defects in 0.01% of parts can still cause accidents but only in those vehicles with the defects.

    Have you driven a gen III prius when the brakes cut out? Do you have experience in designing motor or braking systems? Do you understand how sensors work, and how they fail?

    I leave you with this quote from fight club

    Narrator: "A new car built by my company
    leaves somewhere traveling at 60 mph. The
    rear differential locks up. The car crashes
    and burns with everyone trapped inside. Now:
    should we initiate a recall? Take the number
    of vehicles in the field, A, multiply by the
    probable rate of failure, B, multiply by the
    average out-of-court settlement, C. A times
    B times C equals X. If X is less than the cost
    of a recall, we don't do one."
    Business woman on plane: "Are there a lot of
    these kinds of accidents?"
    Narrator: "You wouldn't believe."
    Business woman on plane: "Which car company do
    you work for?"
    Narrator: "A major one."


     
  17. geognerd

    geognerd New Member

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    I've experienced the sensation of decreasing braking power a few times. It's happened while braking on very bumpy surfaces at speeds greater than 35mph or so. Maybe there's some wheel hop or the system notices a wheel is slowing too quickly because it lost contact with the road for a split second. The same has happened to me while braking in wet conditions and a wheel slips on a smooth manhole cover. It feels like the car is speeding up, but in reality I bet it simply isn't slowing as quickly as it was before you hit the bumpy or slick spot. Thus the sensation the car is speeding up. The key is to have the proper reaction to this sensation. When I feel this, I press the brake harder and the car will slow down. Only a fool would panic and let off the brake when they perceive a loss of braking.

    The Prius is the first car I have ever driven with the bevy of traction-related systems like VSC, ABS, and traction control. This phenomenon wasn't something I was expecting, but I didn't freak out when it happened. I just pressed the brake harder and everything came out fine.

    And no, I do not brake too late/too hard. I am the guy who ticks off everyone behind me because I will coast a long way to a stoplight. I have found driving like you don't have brakes is key to achieving good fuel economy. No sense in wasting momentum.
     
  18. JamesWyatt

    JamesWyatt Señior Member

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    The only Prius braking issue I've ever experienced is with the traction control. I was familiar with this type of behavior having owned a few 2003-2004 Land Rover Discos. The Discovery had the exact same issue with their traction control system – if you were applying the brakes when the front tires hit a good pothole or lane marker, the brakes let up and the ABS kicks in as the system thinks there is a loss of traction and therefore control. The problem is this happens in normal circumstances, such as coming up to a red light or changing lanes before a toll booth. In the Discovery, I "ABSed" myself about 8 feet into an intersection once – foot firmly on the brake pressing as hard as possible. When we traded the Discovery for the LR3, it had a completely new traction control hardware/software design, and I NEVER ONCE experienced this type of braking problem. I tried to replicate the issue on the LR3 and never could... it just always stopped dead solid (as have every other ABS equipped vehicle I've owned save the Disco and Prius).

    So in my 2007 Prius from time-to-time I noticed this same bad traction-control behavior... but it's way easier for the Prius to recover than a top-heavy SUV with a winch and off road bumper :) I still think it's a potentially dangerous characteristic of some traction control systems that needs to be "dealt with" by driving habits. Any time I'm coming to a stop in the Prius, and I know I'm about to hit a bump – I momentarily let off the brake until I go over the bump.
     
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  19. LaughingMan

    LaughingMan Active Member

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    Your sentiment that ABS and VSC are useless may be you just tooting your own horn about how you are a good driver, but that doesn't change the fact that there are millions of other drivers on the road today that are of substantially lower driver skill than you who don't know how to properly pulse a conventional brake or how to handle fishtailing.

    In that regard, technology like ABS and VSC have saved lives. Period.

    They've made less skilled drivers less likely to be in an accident, and therefore, they've made you less likely to be in an accident since you drive on the same roads as these other drivers, even if you never use the feature. The risk of unintended side effect is far outweighed by the lives saved for the intended use of these features.

    I think we have to be careful with longing for the "good old times." Nostalgia for the non-technology laden past where a brake was a brake, and learning to drive meant a standard shift, and where cars weren't built out of plastic and aluminum but of steel... Nostalgia is quickly becoming one of my least favorite sentiments.

    Every era has its problems, and we lose perspective as to the dangers and the challenges of the past as it fades into memory... just a reminder to those who think a 50 year old car is more safe because it has "more solid construction" : IIHS 50th anniversary
     
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  20. ronhowell

    ronhowell Active Member

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    Another way of looking at it is that they have tainted the driver pool to an extent that unskilled drivers who would formerly have been written off are now in charge of advanced tech vehicles which they haven't a clue how to operate!
    Perhaps driving tests should be revised to incorporate instruction and education on these advanced systems, so that people have some idea what to expect when driving in less-than-ideal conditions.
     
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