Toyota Says Prius Brakes Had Design Problems

[Omaha Steve]

Source: NYT

By MARTIN FACKLER, HIROKO TABUCHI, and MICHELINE MAYNARD

TOKYO — Toyota said Thursday that its hybrid Prius had problems with its anti-lock braking system and left open the possibility of a recall, the latest blow to the beleaguered company and one that affects the symbol of the automaker’s engineering prowess.

The Prius has been drawn into the mounting crisis for Toyota as Japanese officials have ordered the company to investigate complaints that the brakes on its 2010 Prius model sometimes failed to work immediately on bumpy or slippery roads. U.S. safety officials also said they had received dozens of similar reports.

Toyota’s manager in charge of quality, Hiroyuki Yokoyama, said the company had identified the problem and corrected the glitch for Priuses sold since late January. He said the company was still considering what actions to take for cars already on the road and had not ruled out a recall.

Mr. Yokoyama told reporters that the new Priuses experienced “a slight unresponsiveness” of the brakes that he said was easy to resolve by pressing harder on the brake pedal. The problem occurred, he said, because the technologically advanced Prius has two braking systems, and a glitch sometimes prevented the car from transitioning smoothly between the two.


Jim Wilson/The New York Times

A new Toyota dealership in Oakland, Calif., is dealing with customers' concerns about recalls.



Read more: http://www.nytimes.com/2010/02/05/business/global/05toyota.html?partner=EXCITE&ei=5043

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FULL story at link.

[dipsydoodle]

1. Its still a bit of a mystery this.

and Toyota's bulk recall across Europe is mainly for safety reasons due to what's happened in the USA.

There are definately no recorded instances of brake issues in the UK : not on Prius's or any of the other Toyota models.

[DainBramaged]

2. Toyota, yes, we have a problem, but we're selling you the car anyway, good luck

What a scummy company.........

[dipsydoodle]

3. Aside from which

it actually confirms the buyer to be a mug for buying one especially if it follows the recall which had been widely broadcast.

Perhaps moves should be made to shut down all USA Toyota production permanently. :sarcasm:

[FarCenter]

4. They changed the regenerative + friction braking system in 2010s

The regenerative braking system turns the electric motors into generators, provides revers torque on the wheels, and dumps the kinetic energy of the vehicle back into stored energy in the batteries.

This is augmented by conventional disk braking, where the energy of the vehicle is converted to heat by the pads pressed against the disk -- an inherently less efficient braking mechanism.

There is apparently some issue with the electronic controls which prefer regenerative braking unless more deceleration is demanded by the driver pressing harder on the brake pedal.

As usual, the MSM is not very clear about these things.

[madokie]

5. I see it more as a problem with toyotas arrogance and denial

You couldn't give me one mind you and its sounding like toyota is going to loose a big market share

[Raschel]

7. Will conservatives blame this on the "lazy workers" like they blame union workers?

[FarCenter]

8. Hybrids are really too complicated for my taste

You have the engine driving the wheels through the transmission at the same time as the wheels are being driven by the electric motors. At the same time, the engine is also driving the generator to charge the battery.

Then, if you shift your foot from hard on the accelerator to hard on the brake, the engines power has to be cut to both the generator and transmission, the electrical motor has to be reversed into a generator with the power flowing backwards to charge the battery, and the anti-lock braking system friction pads applied to slow the vehicle.

Seems to me that the type of system going into the Chevy Volt is much simpler. The engine runs intermittently at constant speed to generate charge that goes to the battery. The battery discharges to power the electric motor driving the wheels.

When braking is required, the drive motors change to generators and the brake pads are applied if needed.

It seems like this would be easier to manage, taking into account the software needed for traction control, automatic stability control, and anti-lock braking.

[madokie]

10. I like the volts setup better too

In fact i see it as the way we'll be getting our autos here in a few years. It makes so much sense to do it the way GM is doing the volt.
When you have a set rpm the engine runs at like the volts is then that engine can be designed to run at that speed and the efficiently increases quite a bit. Do it like the trains have been doing it for years now. I don't ever remembering them building a locomotive that the engine was directly connected to the drive wheels since they've been using diesel engines as they've always been diesel engine connected to generator running electric motors turning the wheels.

[FarCenter]

12. The Hybrid is Toyota's way of engineering around the Chevron-Texaco patents

Toyota uses NiMH batteries. It can't make a serial engine-generator-battery-motor vehicle because of the GM patents that were sold to Texaco, which merged with Chevron.

http://en.wikipedia.org/wiki/Patent_encumbrance_of_large_automotive_NiMH_batteries

Lots of good technology is shelved for 20 years until the patent has expired or until the patent can be engineered around.

Ever wonder why Fords had the Flathead V-8 from '32 on, while Chevy introduced the V-8 in '53?

[tridim]

6. WTF? Is Toyota comitting suicide?

This is all so strange to me since I used to consider Toyota a quality car maker as recently as 10 years ago.

[joeglow3]

11. This is older than just recently

As stated in another thread, the gap in quality with Toyota and American brands was closed years ago. However, the uninformed consumer is too lazy to do any research and were more than willing to continue paying a huge premiums for the car. I think Toyota got arrogant and lazy.

[tridim]

13. I should clarify, I've never bought a Toyota..

Just driven two of my parent's Toyotas. A mid-80's Corolla (that lasted forever) and a late 90's mini-van type thing. Both were great cars.

As for research, I probably study for about 80 hours before buying any car, new or used. My Dad taught me how to be an informed consumer. It's an annoying habit, but usually results in getting the best car I can afford. I even did this at the library before the Internet existed. :)

[joeglow3]

15. Very smart

I learned the lesson the hard way when I bought my first car. I think I had trouble sitting for a month.

[fujiyama]

19. It's been narrowed for some five years now - according to most surveys

and Toyota has been charging customers more based on a legacy of quality, rather than really offering anything innovative.

Toyota decided to go for market share and volume, rather than focusing on quality at the share they had. The big question for the last three years or so was "Can Toyota do both?" (increase market share, pump out a lot more cars and keep the quality high as they were known for).

I think we got our answer.

[Endangered Specie]

20. Seppuku, actually.

[miyazaki]

9. Ah Give Me A Brake! n/t

[LeFleur1]

14. What Happened?

We've driven Toyotas for a long time and never had one problem. Not one. Now they have a recall. They've ceased selling cars until it's fixed. Should recalls happen? No, but they do. All auto companies seem to be in a hurry to get their cars on the market before they have been vetted (so to speak). Toyota is no worse than other companies, and in a lot of ways it is better.

[MidwestRick]

16. The big question is this...

Who is the braking supplier who designed the brakes. The auto companies don't, that is left up to the tier one suppliers. There are very few brake companies any more and since it's Toyota, I would hazard a guess that the company that designed these improperly is Akebono. With that said, how many other vehicles use similar designs in their anti-lock braking systems?

This story has legs.

-MR

[FarCenter]

17. The supplier is CTS Corp of Elkhart, Indiana

http://www.ctscorp.com/

While Toyota presumably has complete design and testing responsibility, CTS Corp appears to have at least one patent on the pedal. Who's engineers screwed up on the friction lever design will probably never be known.

The pedals used on no-recall modela and in Japan are from Denso.

Peugeot/Citroen, Ford, and Renault have recalled a small number of cars that use CTS Corp pedals. In the Peugeot and Renault cases, these appear to be models that are made for them in Toyota factories. Ford appears to have independently selected the CTS Corp pedal for a model made in China.

[blue_onyx]

18. Not all companies having problems

"CTS also supplies throttle assemblies to Honda, Nissan and Mitsubishi. Those companies say their designs are different and pose no risk of sticking open."

http://www.usatoday.com/money/autos/2010-01-25-toyotalong_st_N.htm?loc=interstitialskip

[Endangered Specie]

21. Oh man, stuck accelator and broken brake...

I'd be afraid to turn one on!