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Toyota Prius Brake Problems



  • Certainly the rear brakes have changed, but I don't know that this requires a software change, and it is the software that I believe is the problem. One change they did make to the software (it is noted in the owners manual somewhere) is to record (black box style) information which would help diagnose what happened just prior to a crash. While having this information is a very good idea, it makes me suspicious that they cannot figure out what the problem is, or how to duplicate it, and are looking for data.

    When I took my car into the dealership in Michigan, I came in with the many page printout of customer complaints posted at . I appreciate that they took me seriously.
  • I have a 3 month old 2010 Prius II and applied the brakes on snow/ice this morning and the brakes completely locked up. I felt no ABS at all. I had let off the brake and pump it myself. I don't have much experience with ABS except our 2003 Honda Odyssey has them and when they pulse you feel them. Anyway, I'm near 5k miles and am going to take it to the dealer to change the oil, disable the incredibly stupid beeping while in reverse, and now report the ABS isn't working. I'm sure I'll get a bunch of bull-crap from them about the ABS. I'll repost once I see what they say.
  • whitey9whitey9 Posts: 138
    ABS has no effect on snow, ice, sand, or loose gravel. If the road surface is loose or unstable ABS does not respond as it does on a wet, or dry road. The more advanced anti-skid ( ASR ) systems help prevent skidding and even spinning around, but NOT plain-old ABS.
  • That's interesting... I was driving my 2010 Prius on snow/ice near South Bend Sunday AM, and the ABS kicked in quite nicely when I did a panic brake maneuver. I have had the ABS work nicely under snowy conditions in my 1998 Saturn. And I learned the effectiveness of ABS under simulated icy conditions during a training program at the GM proving grounds in 1996. Granted, in these cases it was quite slippery, more like icy conditions rather than loose snow or gravel. One of the paradoxes of our technologies is that we tend to depend on them and therefore don't learn how to respond when they can't cope with the situation at hand, and we take bigger risks assuming they will cope.
  • I've had my 2007 Prius for almost a year now. Back in Feb I experienced the total brake failure problem. The parking break light was on (but the peddle was up), the ABS light came on, and the excamation point light was on. I aimed for some grass on the side of the road and coasted to a stop, and had the car towed to the dealership. They poked at it, and said there was a code (didn't tell me what) and that they had cleared it to fix the problem. Good as new.

    4 days ago it happened again. same exact scenario. I managed to limp it home and take my wife's car to work that day. We took the car in again Sat driving about 25 mph the whole way. Wouldn't you know it, by the time I got to the dealership, the error lights went out, and the brakes were magically working again.

    I told them to take the time actually figure it out this time. I didn't even get back home before they called me up to tell me they were ready for me to pick it up again. (Really? Full in depth investigation into a critical system failure in less than 20 minutes). I went back to pick it up and was told that the error this time was the error from 14000 miles ago that for no good reason the computer "pulled back up from cache". They said they did a hard-reboot on the computer and that it is now totally fixed.

    This sounds like BS to me, and my wife won't let me drive my car anymore. Has no one figured this out yet? I love my car, but if I can't drive it, I might as well trade it in for something else.

    The one thing I can add is that in both failures, it was very cold out. I have a tendency to leave the parking brake engaged when not in the car, and the first indication of a problem in both cases was that the brake light did not turn off when I released the parking brake. I don't know if that might help a gear-head figure out what is really wrong, but it might be a suggestion that Prius owners always do the same, and not leave the parking lot if the brake light stays on when they release the brake.
  • Although not directly related to the exact brake issues in the past few posts, please see this article published today about other braking issues with the Prius. rids/#more-17003
  • One thing I think everyone should do is make sure they know the basics of driving.
    What I mean by this is you should know how to drive a good old fashioned car with none of the bells and whistles or any of the electronic "crutches" that newer cars have. All the new "safety features" on newer cars are depended on way to much, resulting in drivers not having the requisite skills to drive the car safely if something fails. Any car that has ABS brakes will revert to good old fashioned standard brakes if something fails in the ABS.
  • whitey9whitey9 Posts: 138
    They will not disablew the "beeping while in reverse gear" system, as this is a safety system, and in doing so, leaves not only you, but them W-I-D-E open to litigation. In other words, if someone one gets hurt or dies, they will change the name on your house deed, and the auto dealership sign to the victims' survivors.
    As stated previously, ABS has NO effect on snow/ice/sand/loose gravel. Also, pumping the brakes is not recommended, just light constant braking way before the situtation becomes dire. Drive safely.
  • I agree in most cases with the author of Take Responsibility For Your Own Driving, krasht. However, in the case of the Prius brake system failures occuring all across the country it is not something that falls under the "improve your driving and predict your next moves" category of accidents (or near accidents). I have been driving valet in busy downtown areas for years and never had more than a rim rub on the curb. After having my '09 Prius for 6 months I found my self in a situation that I have maneuvered my way out of tens of times before. But, with the braking being completely trumped by the recharge system for a few seconds there is nothing anyone can do to stop besides running into an object. A few seconds is a life time in such a situation. And in that lifetime of seconds we all hope to God that that object is not a pedestrian.
  • kdhspyderkdhspyder Posts: 7,160
    As noted just above by whitey the ABS has nothing to do with stopping you in a shorter distance. It's Brake Assist that does that. Brake Assist is activated by the manner in which the brake pedal is hit.
    BLAM>>> hit it hard and hold it down, then BA activates and you come to a screeching stop. I've done it many many times.
    PRESS it normally and then jam it down to stop and BA doesn't activate.
    It's the same in all vehicles.

    ABS will not help you to stop shorter in a panic situation. That's a common misconception that needs to be clarified. ABS only keeps the brakes from locking up the wheels so that the operator can steer out of danger. It has no other function. When it's activated you feel the vehicle and the pedal pulsating.

    Wet and slippery roads will make stopping longer, there's no way around that.

    The issue being monitored by the NHTSA is being discussed and analyzed by very knowledable engineers and techs over on the major Prius sites. Apparently from what those who've encountered it can explain it seems/feels like a surge as the braking switches from regen to hydraulic/friction braking. It only occurs at moderate to slow speeds and only when the tires hit good-sized bumps or defects like potholes. The sensation lasts about a half a second, but from what the various testers are discovering there is no increase in braking distance. It's a sensation to the operators but the vehicles stop as they should.
  • kdhspyderkdhspyder Posts: 7,160
    There are NO brake system failures all over the country. That's a gross exageration. The system is different and it feels different to new operators but they stop as they should. If the feel is not to your liking then the vehicle might not be for you but for your single experience there are literally hundreds of thousands of others who a) have felt it but know how to handle the feeling or b) have never felt it.

    In my 140,000 miles or so if I ever felt it the sensation was so minimal that I adjusted immediately and continued without any reaction.

    If the sensation is too severe for you to handle then you should unload the vehicle rather than be unhappy. I on the other hand plan to put another 140,000 miles on mine.
  • hal_cathal_cat Posts: 11
    OK, I have probably only driven 800,000 miles, and I only took advanced driver training on the GM Proving Grounds once so that I would be qualified to drive on the test tracks there, including skid control with anti-lock brakes, so it could be that I didn't know what I was feeling when I stepped on the brakes in my 2007 Prius, at a fairly low speed, and the car kept rolling right into the rear bumper of an Imperial that was stopped in the road. Having driven that Prius for 2 years did give my some feel for knowing when the brakes were applied, but perhaps I should drive one some more to fully understand the difference between brakes applied and brakes doing absolutely nothing. I do know that I had my food on the brake pedal and not the accelerator since the engine did not rev up. I also know that the floor pads were not the problem, since the next time I tried to use the brakes they worked just fine. I will have to admit that I don't know how a brake failure feels on other cars, but the brake failure on my Prius was definitely not to my liking.

    When someone posts a message that they had a problem with their brakes on a Prius, I am very tempted to believe them since I've been there and know quite well how it feels. And having talked to the people at the NHTSA I know that they are taking it seriously too.
  • kdhspyderkdhspyder Posts: 7,160
    No one ever said anything about floor mats. At this point the main discussion seems to be revolving around the transition from regen braking to hydraulic braking and the feel of that transition.

    Loss of braking entirely? If there are instances like yours then they appear to be very very isolated in a population here of Prius drivers totalling several hundred thousand. Why your case resulted in an accident once but not every time you braked is certainly curious. Now that they work again, curious again.

    These sporadic anomolies that cannot be repeated are the worst kind to try to resolve. If there doesn't seem to be a problem when the vehicle is brought in, what is it that the techs or the engineers should attempt to fix?
  • I had a similar experience with my 2009 Prius and have been driving it for months. The braking system is different than my previous Corolla- but I have adapted to it and there was nothing I could have done in my accident in Dec. 2009 where my brakes failed to work at a low speed. When I applied my brakes there was no response, no acceloration no slow down. I tried everything I could to avoid the accident but ended up rear-ending the car in front of me. Even my coworker who was in the car was suprised that the brakes just stopped working and the car was able to drive fine after the accident. Toyota came back with nothing and this really upsets me that there is nothing that they can do about it. And it scares me that other people have posted similar incidents and it is so difficult to replicate.
  • I am a high mileage driver and have been through many cars through the years. I have had my 2010 Prius for 5 months and love it but I have experience a problem twice now. Both times I had gone from park to drive so was a dead stop. What happens is that I engage the break, put the car in drive, and as I release the brake it accelerates forward - it is like in the old days when an engine would rev up but being in electric mode it is silent - at the same time the brake pedal locks at a very high level and the slightest release of pressure causes the car to lurch forward. The most recent time I was in the maintaince gargage after just getting my 5000 servicing. The guys inside started laughing because they thought I was afraid to approach the automatic doors as I lurched forward and stopped a few times before I just stopped and waved them over. When I put it in park I could feel the brake pressure release to a normal level and it was all over. I don't think the guys believed me and said they did nothing to cause it. I explained it was the 2nd time it happened. This is not something I'm willing to give up my car over just something that I am now aware of since it has happened twice. I was wondering if anyone else has experience similar problems.
  • I've had both of these events occur. I have tried to bring it to the attention of Toyota with no avail. I've was a valet for 4 years w/o a fender bender - then, after 6 months in my '09 Prius I had a low speed break failure and hit the car in front of me. This deserves a recall with an actual fix.
  • I have a new 2010 Prius, one month old and have experienced the surge problem mentioned above at least three times. It happened at slow to moderate speeds, and at least twice downhill over moderate bumps. This surge or acceleration increase is unacceptable and may be a warning of a complete break failure in the future. Toyota should take this one seriously.
  • I have the 2010 Prius, within a month of having the car I was in the dealer having the brakes checked- I have been a total of three times, all with issues relating to feeling of brake failure while slowing down on a bumpy road..they sent a "specialist" on the third visit, and we could not duplicate the issue. I was told to remove my floor mat which which we did- bottom line you can stop the car, you do not actually loose the brakes, there is a delay, if you slam on the brakes you will stop hard and potentially have the car behind you slam into your rear..there is a braking issue, the latest complaints are going to be good for us Prius Owners- perhaps now they will acknowledge the issue and address it...still I love my car...
  • 2010 Prius. First Prius, about my 5th Toyota, 20th car. First the lurch when going over a pot hole. I live in the mountains and have experienced this twice, and I am sure I can repeat it whenever I'd like, which I wouldn't. It was disturbing, but I was non-plused noting immediately that it did not effect my braking distance, but it is a "spooky" feeling - like hitting ice without the attendant slide into the embankment. I let my wife know about the "quirk" so she wouldn't freak if it happened to her. In the mean time, we avoid holes in the road.

    The "surge" has happened twice too, and I expect it will happen again. It has only occurred to me after the car has gone through the car wash and is on the down hill grade driveway at this particular car wash. The other car wash I use is flat and I have not experienced it there. It's alot like when a very stiff clutch is let out too fast and then you push it in, let it out, etc. Hoppity hoppity. The first time it happened I wasn't too worried as the first time my G35 Coupe came out of the wash I had NO brakes for a second or so. Now that was scary (the car's a rocket)! But knowing the Prius may buck and jump, I now just be sure to use "light" pressure and not try to inch my way across the sidewalk. I just make sure the road is clear and drive away. Ditto informing the Mrs.

    I have no worry Toyota will issue a recall if it's needed. As a student of the TPS and a 6 Sigma black belt, I have high confidence in Toyota to resolve the issue, if it is more than just a quirk of the series. It is interesting to note that the people below reporting low speed brake loss all seem to be in 2009 models. Is that a common trait (I haven't read all the thread, just a dozen or so).
  • Karen_CMKaren_CM Posts: 5,020
    We are receiving requests from reporters/journalists seeking to interview Prius owners with this issue. If you're willing to be interviewed, please send an email including a phone number and the best time(s) you can be reached to


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