Sorting Out Hybrid Brake Issue: Safety Issue or a Different Feel?

Coming at the heels of Toyota’s problems with sticking accelerator pedals, news of potential braking problems on the 2010 Toyota Prius and Lexus HS250h hybrid has raised legitimate concerns among hybrid owners. Yet, media coverage of Toyota’s safety issues may be blurring the lines between a potentially fatal problem with the accelerator pedals—resulting in a massive recall of 4.5 million Toyota vehicles—and the hybrid braking issues that may largely be based on perception.

First, consider that the National Highway Traffic Safety Administration has received nearly 200 consumer complaints about the 2010 Toyota Prius’s braking performance—while approximately 103,000 units of the 2010 Prius are on US roads. (Each of these case must be investigated before any conclusions can be drawn.) It’s also interesting to note that in Japan, where the 2010 Prius has been the No. 1 selling car for six months and 200,000 units have been sold, the Prius braking issue “hasn’t registered on the national radar,” according to National Public Radio reporter Lucy Craft. She characterized the coverage in the US as a “hysterical reaction,” compared to the response in Japan.

NPR added that Toyota doesn’t believe there are any “defects” and any problems related to the driving experience can be “fixed fairly easily by adjusting some software.” That’s exactly the position taken by Ford to some customer complaints about braking in the 2010 Ford Fusion Hybrid and 2010 Mercury Milan Hybrid. “While the vehicles maintain full braking capability, customers may initially perceive the condition as loss of brakes,” said Ford. “There have been no injuries related to this condition.” Toyota informed HybridCars.com that “there is no loss of braking control.”

In an interview with local ABC News, Wayne Mitchell, co-founder of a local Prius chat group in Chicago, said, “The sensation you have is like your accelerating, but in actuality you’re just coasting.” He explained that the brake pedal doesn’t feel engaged going over an uneven surface, even though it is. “If you were just to push a little further into your brake pedal, the brakes—the regular brakes—are there. They’ll come on and they’ll stop the car,” said Mitchell.

Ford attributed the sensation to “a different brake feel when the hybrid’s unique regenerative brakes switch to conventional hydraulic braking.” Ford is planning to ask Fusion Hybrid and Milan Hybrid owners them to bring in their cars to be reprogrammed at dealers at no charge.

Mitchell’s coworker Felipe Torres, who also drives a Prius, said, “You always have braking power, you have the ability to stop the car, but it might make people more comfortable not having that sensation on occasion,” said Mitchell.

Aaron Bragman, an automotive analyst at HIS Global Insight, told the Wall Street Journal that some drivers are unfamiliar with the idea that hybrids drive slightly differently. “The brakes are different and the regenerative system is different. It’s a learning curve when you’re driving a hybrid.”

Regenerative braking is a key function of hybrid cars—as well as the plug-in hybrids and electric cars expected in the coming years. These systems have been put to use in hybrids since 1997 in Japan, and 2000 in the US. There are nearly 2 million hybrids currently in use in the United States.


  • TD

    the coverage in the US as a “hysterical reaction,”

    Isn’t that the US media’s reaction to every story? The US media also likes to pick on leaders and let them know who’s boss, at least in their minds. Perhaps GM can be thankful that Toyota is taking over the role as lead automaker punching bag.

    In my hybrid it took me a little while to get used to the difference between the brake generators kicking in and the actual brakes kicking in. I hardly notice it anymore tough.

  • Toyota Driver

    When I first drove the prius, my first reaction was “wow, the brake is much more sensitive than any other cars I’ve driven”. (and yes i’ve driven many other cars)

    I don’t there is anything wrong with the brakes, but maybe the software logic do need to be adjusted as what ford is doing to the fusion hybrid.

    also, some drivers will never be satisfied. They will expect the car to stop even when their car hit a pot hole and the tire is briefly airborne.

  • PriusNorm

    Why is a sticking accelerator pedal “potentially fatal”? There was a guy in a Lexus who crashed at 120mph having had time to call 911.

    Is there something that prevents the vehicle being put into neutral? Meanwhile the brakes will curb any acceleration.

    What this does raise though is the spectre of having potentially fatal software between the driver and the essential controls.

    My 2008 Prius will NOT allow the engine to be stopped until the car has stopped. The gear shift is software controlled as is the switchover from regen to hydraulic braking. If the car s/w went totally beserk (and it hasn’t) then the driver is helpless. Aircraft have multiple parallel systems to protect against this – cars don’t.

    Perhaps we need a big red handle under the steering wheel …”Pull to stop”.

  • AP

    PriusNorm,

    I read that the driver in the Lexus tried to shut the car off by pushing the “ignition button,” but didn’t know it has to be pressed for 3 seconds to shut off when moving. I don’t know about putting it in neutral, but some people freak out when they hear the engine race, and put it back in gear!

    As an automotive engineer (at GM), I have seen cars become more and more reliable over the last 25 years, while requiring less and less maintenance.

    While this is generally a good thing, it does require less and less knowledge about how cars work, and when you don’t know how they work, it is amazingly easy for people not to know what to do in an emergency. I have known people who

    1) think that traction control means you can accelerate just as fast on snow as on dry pavement, ABS means you can stop just as fast, and complained when it didn’t,
    2) didn’t know you could use 4-wheel-drive in mud,
    3) thought that revving the engine “accelerated” the car, and
    4) never used the front brake on a motorcycle, for fear of locking it up and losing steering (as opposed to the rear brake locking up and having the bike spin out completely).

    As a nation, we have become “mechanically declined.” We can’t think things through by ourselves. Then, when we do have problems, we blame others.

    When you learn to fly a plane, the instructor often shuts the throttle off and has you find the best place to land, line up for an emergency landing, and only opens the throttle up when you’re about 100 ft up. If our driver training was 1/4 as thorough, we’d know what to do when the time comes.

  • alancamp

    I believe it was a Toyota official that stated the ‘lurching’ of the 2010 Prius would cause a car traveling at 60 mph, to travel an additional 60 ft before stopping due to the brake ‘lurch’. So there is a serious safety problem for those driving the 2010 Prius and those around them.

    However, a ‘Hysterical Reaction’ is ALL that American media does. They are like a pit bull with a bone. It does not matter the damage they cause in their effort to be ‘first’ and ‘break’ the story, or to try and find the most damaging information about their target, and anyone in their wake.

    BTW….the blogs don’t help much either, since all content is ‘published’ equally, and anyone with a pc can be a ‘journalist’ on the web. So the line between any ‘implied’ facts relating to whatever the issue was, becomes whatever the general public ‘thinks’ from their perspective. To make a buck. Which only sets the stage for conflict. With no regard for the facts whatsoever.

    True journalism is ‘without’ advertising, but add advertising and it all becomes an ‘advertisement’.

  • Allannde

    As the Internet makes bloggers and people like us are able to get our voice out almost instantly, a company like Toyota is a huge bureaucracy which must have MANY levels of approval before it can respond. As a result, its “PR” stinks.

    On top of that, Toyota, in Japan, is really revered as the savior of a troubled economy. The Japanese don’t have even as much separation between the state and big companies as we do so it is a patriotism thing over there. It boils down to a cultural issue as well.

    The quality built in to Japanese cars has made ALL cars better.

    The reason that this will blow over is that the Toyotas are basically good cars. After all, it will not look like the “problem” was as bad as it seemed. But the noise is not over, yet.

    Actually, this might be a smart time to pick up some Toyota stock and make some money.

  • Anonymous

    As the Internet makes bloggers and people like us are able to get our voice out almost instantly, a company like Toyota is a huge bureaucracy which must have MANY levels of approval before it can respond. As a result, its “PR” stinks.

    On top of that, Toyota, in Japan, is really revered as the savior of a troubled economy. The Japanese don’t have even as much separation between the state and big companies as we do so it is a patriotism thing over there. It boils down to a cultural issue as well.

    The quality built in to Japanese cars has made ALL cars better.

    The reason that this will blow over is that the Toyotas are basically good cars. After all, it will not look like the “problem” was as bad as it seemed. But the noise is not over, yet.

    Actually, this might be a smart time to pick up some Toyota stock and make some money.

  • Casey Verdant

    This is bad news for Toyota. Recalling the 2010 Prius for brake glitches will tarnish the reputation of the maker and the model. Hybrids and electric cars are the greenest technology in the mainstream and it would be a shame to see their production and popularity stalled over safety issues.

    Researching how to make your company, product, or next project more Green? Go to http://www.greencollareconomy.com for sustainability white papers and the largest b2b green directory on the web.

  • PriusNorm

    Thanks AP,

    I agree entirely with what you write. As for the Lexus driver, a motor bouncing off the rev limiter (you would think) would freak him out less than a 120mph crash and 4 deaths. But then people don’t act rationally in such situations I suppose. If they surviive, they blame others, as you say.

  • Anonymous

    I have experienced something akin to what is being discussed in my 2010 Prius. However, my experience happens when I am travelling about 25 mph and quickly depress the break (usually in traffic situations). The car lurches forward a bit when I step on the brake. To me, the “lurch” seems like the electric motor does not disengage and still tries to drive the car forward and before it cuts out a half-second after stepping on the brake. Since it has happened many times, and not while hitting any bump, I am not sure if what I experienced is related.

    As for the media overblowing this… I feel I can compensate for this “glitch” (not that I expect it) but heaven help me if it happens to my wife with the kids in the car and someone gets hurt. So nothing can be overblown with saftely involved.

  • Skeptic

    I don’t own a hybrid and now I am skeptical of them. I don’t want software between me and the master cylinder. If I say stop, I want the car to stop. Period. I don’t want some piece of software written by a group whose manager said “just get it out the door, we can patch it later” to decide that “No, I think regen is called for here, hold off on hydraulic”.

    That’s BS.

    If I lose a bit on efficiency, I don’t much care. Besides, there’s nothing to stop regen from engaging *after* the real brakes kick in.

  • ex-EV1 driver

    Skeptic,
    Every car with ABS (nearly every car built since 2000) has software and electrons between the master cylinder and the brake pads so I’m not sure why you’re getting so excited about having them between you and the master cylinder too.
    Of course, I like Tesla and AC Propulsion’s approach to regenerative braking better than the big car companies’. Regen on the Tesla is accomplished simply by letting up on the accelerator (‘gas’) pedal, just like engine-braking with a manual transmission. The friction brakes are just ordinary power-assist ABS disk brakes, used really only when strong braking is needed or to hold the car at a stop. This provides very safe, convenient control of the car in normal driving. Mountain driving is pure pleasure.

  • cld

    I’ve experienced this same “problem” in my 2005 Prius on a few occasions, accompanied by the VSC light coming on briefly. I interpreted the phenomenon as the VSC blipping the throttle to prevent brake lock-up, similar to the way it’s applied on a Formula One car. It may be unsettling if you’re not used to it, but the alternative would be for the brakes to lock up and cause the car to spin. I believe Toyota is fully aware of the issue because that is how they intended the car to operate. The media coverage (muck-raking?) so close to the accelerator issue has forced their hand to take action on what is essentially a non-issue.

  • PaulRivers

    Let’s see, for years Toyota ignores reports of accelerator problems. They say “it’s not a big deal, don’t worry about it”.

    Finally, someone manages to call 911 while they’re in motion in a vehicle that won’t stop. They crash and burn in a fiery blaze, killing everyone in the vehicle.

    Toyota says “Oh, it was just a stuck floor mat. We’ll replace them, or take out your floor mats – it’s not a big deal, don’t worry about it.”

    Months later, and only because of a lot of prodding from the US government, Toyota comes out and admit there’s a serious defect with the accelerator pedal.

    Now there’s a problem with the Prius braking. A problem which Toyota found out about and fixed (I guess that’s a step up because they actually looked into it, right?). But hey, guess what Toyota says – “It’s not a big deal, don’t worry about it”.

    At this point, I think only an idiot would take what Toyota says at face value, not that I completely trust anything a corporation claims at any point.

    Heck, the problem isn’t even that this happened. The problem is the “oh, gee, I’m sure it’s not our fault” philosophy. We’re talking about the goddamn *braking system* here. This isn’t a question of whether the window can roll down or the stereo controls work. This system should just work – period.

  • AP

    cld, you might “blip the throttle” on some race cars when down-shifting, with either a manual transmission or a sequential shift racing trans. That’s either to to keep the brakes from locking up, or to get the transmission to engage the lower gear. But ABS isn’t allowed in most racing series, so you have to drive differently.

    There is no reason to delay braking like that on a car with ABS. A properly operating ABS system will back off on the brakes if and when necessary, to keep the braking steady.

    Further, if any tires locked up on your Prius during “engine-braking” or re-gen, it would be the front ones (since it’s front drive). This would not make your car spin out; locking up the rear tires (the driven tires on a real race car) does. Locking up the fronts makes the car slide nearly in a straight line; not as desirable as keeping the tires turning and braking more effectively, but not nearly so bad as a spin-out.

    I just wanted to make sure no one got the wrong impression, and thought that an unnecessary braking delay like that was normal.

  • alancamp

    The only Toyota I ever owned was the 1979 Celica I bought at 17 years old. The fun went out of my sails when at 3 years old the master cylinder failed, and I flew through a stop sign, luckily no one else was in front of me and no cross traffic. Sadly the repair was not under warranty and I had to pay $300 for the failed brake part.

    I didn’t trust the car after that, and bought a Honda Prelude. It’s been 5 Hondas since then. Everything works….no brake problems.

    Most anything else on a car that fails is just annoying, but when brakes fail, or are in question…it’s scary.

  • NCG

    I have owned a 2008 Prius for two years, and I have experienced the same braking problem. If breaking moderately hard, and then I hit a road surface that is a bit bumpy, the brakes let off about 50%. Sure I press harder and the brakes are right there, but I’ve lost about 15 feet from the braking gap. That 15 feet almost resulted in an accident once. But I will say this…When the Prius brakes are engaged, they are fantastic! I have owned over 20 cars, and this car has the best gripping brakes I have ever had. The seatbelts actually hurt if I panic break. Now thats some good brakes. There is an answer to this and Toyota must fix it. It’s not an acceptable quirk.

  • Craig Parmerlee

    I have been driving a 2010 for about 6 weeks. I am with a car rental company and we have about 50 of them in our fleet.

    I definitely noticed weirdness in the brakes within the first few days of driving. At that time, there wasn’t any snow on the ground, so the problem only cropped up on loose pavement, gravel and such. Whenever it happened, I thought, “That was really weird” — like the tires were not even in contact with the group. There was absolutely NOT BRAKING at all for an instant — and it is more than a few milliseconds — nearly a second.

    Now that we have a lot of sno, this is happening a lot. It is a big problem. We won’t rent these things to our customers until we get tem fixed. You can’t have vehicles that routinely shut down the brakes for nearly a second/

    It is definitely not a hysterical reaction. If anything, I’d say the media has been far too willing to give Toyota a pass on this because the media buys into that narrative that the Japanese cars are better quality.

    It is truly outrageous that Toyota knew about the problem, developed a fix, deployed that fix on their new production vehicles delivered in January, and was still trying to bluff their way out of fixing the vehicles they had already shipped. That is terrible.

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    Nice blog..sorting & inspection is essential in manufacturing company.

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