[Quietcars] Toyota admits Prius had brake design
michael townsend
mrtownsend at optonline.net
Wed Feb 10 16:43:05 UTC 2010
Thanks, Bob. I've saved this note as well. I appreciated the update.
Toyota will rebound and they're a concerned, caring and consumer oriented
company.
Mike
-----Original Message-----
From: quietcars-bounces at nfbnet.org [mailto:quietcars-bounces at nfbnet.org] On
Behalf Of Robert Wilson
Sent: Wednesday, February 10, 2010 9:40 AM
To: quietcars at nfbnet.org
Subject: Re: [Quietcars] Toyota admits Prius had brake design
Hi Mike,
I wanted to update the status of what we are calling the brake pause. Toyota
has released a fix called SSC-A0B and two early adopters report that it
works. First a quick recap of the 2010 Prius brake pause problem.
It appears to happen with three conditions: speeds under 19 mph; and the
brakes are lightly applied; and a slippery surface that activates the
Anti-lock Brake System. It takes all three conditions, which explains why
only half of the 2010 owners in January could report having experiencing it.
I didn't experience until Friday, February 5, as a brief "sliding sensation"
when crossing a speed bump during a drizzle. Fortunately, I had a recording
accelerometer running and captured the event.
At the entrance to the speed bump, the car was moving at just under 18 mph
and I was braking softly as I approached the guard station about 40 paces in
front. As the car went over the bump, the braking forces showed the pulsing
associated with antilock brake action. Just as the car cleared the speed
bump, all braking force paused for 700-800 milliseconds keeping the car
speed at 17 mph covering a distance of 6 to 7 paces. There was a brief
feeling of sliding, not unusual on Huntsville, rain slick streets. Others
have reported that rapid application of the brakes stops the car
immediately. But holding the brake pedal constant and the braking force
returned about 800 milliseconds later and the car continued to slow down.
Early Monday morning, February 8, we got a world wide recall notices for all
2010 Prius to have the skid controller software updated. Three early
adopters report it takes less than an hour, closer to 30 minutes, to get the
upgrade. Two of them reported that past places no longer show the braking
pause.
It will probably take a month to get all of the 2010 Prius back to the
dealers and get the fix. Yesterday, I left a message with my dealer to find
out if they are ready to fix our car and I'll probably have them change the
oil at the same time. The brake pause can be completely handled by pressing
harder on the brake pedals causing the car to stop almost instantly.
There are reports that the earlier 2004-09 Prius have a similar braking
pattern. However, the 2010 Prius braking system was redesigned and uses
different software. Speculation on my part, I suspect the earlier Prius will
eventually be recalled and fixed.
One slightly related news item is Toyota has announced a recommitment to a
more sensitive quality control system with these elements:
1) Improve Quality Inspection Process
2) Enhance Customer Research
3) Establish Automotive Center of Quality Excellence
4) Support from Outside Experts
5) Increased Communication
6) Improve regional autonomy
A press release is one thing and the practice can be something else. So I
remain skeptically, optimistic. If Toyota pulls this off, they will set a
new bar for excellence. This braking pause problem and the run-away
accelerators have been a 'wake up' call and hopefully will renew Toyota's
commitment to quality.
Bob Wilson
ps. For those with a technical interest, here are some photos of locations
that exhibited the brake pause and the Friday incident captured by an
accelerometer:
http://hiwaay.net/~bzwilson/prius/Prius_bump_010.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_020.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_030.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_040.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_050.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_060.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_070.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_080.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_090.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_100.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_110.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_120.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_130.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_140.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_150.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_160.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_170.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_180.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_190.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_200.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_210.jpg
http://hiwaay.net/~bzwilson/prius/Prius_bump_220.jpg
The following shows graphs of the Friday incident:
http://hiwaay.net/~bzwilson/prius/Prius_brake_030.jpg
http://hiwaay.net/~bzwilson/prius/Prius_brake_040.jpg
http://hiwaay.net/~bzwilson/prius/Prius_brake_050.jpg
http://hiwaay.net/~bzwilson/prius/Prius_brake_060.jpg
It is a difficult problem to reproduce because of the combination of
factors. Drop any one of them and the braking pause does not occur as this
normal speed bump passage shows:
http://hiwaay.net/~bzwilson/prius/Prius_brake_010.jpg
http://hiwaay.net/~bzwilson/prius/Prius_brake_020.jpg
> Date: Thu, 4 Feb 2010 15:22:39 -0500
> From: mrtownsend at optonline.net
> To: quietcars at nfbnet.org
> Subject: Re: [Quietcars] Toyota admits Prius had brake design
>
> Thanks for this, Bob. It's welcoming news when someone as yourself
> takes it upon themselves to replicate conditions and to verify what is
> bounced off of us in the media. Years back, during the heyday of
> Chrysler and Ford's recalls, the media was less zealous than they are
> now, and internet look ups weren't widely available, nor were quickly
found data bases.
> I appreciate your efforts.
>
>
> Mike T
>
>
>
> -----Original Message-----
> From: quietcars-bounces at nfbnet.org
> [mailto:quietcars-bounces at nfbnet.org] On Behalf Of Robert Wilson
> Sent: Thursday, February 04, 2010 10:45 AM
> To: quietcars at nfbnet.org
> Subject: Re: [Quietcars] Toyota admits Prius had brake design
>
>
> Hi Michael,
>
> This latest news from Japan of a technical fix is certainly welcome
> news to 2010 Prius owners. I wanted to share some of what we've found
> in the Prius community.
>
> In a 30 day poll, about 50% have reported experiencing the brake problem.
> I'm one who hasn't experienced anything beyond what happens when only
> two of dozens potholes have been hit lasting only at these two pothole
> ... not beyond. Of the 50% who reported experiencing the problem,
> about 20% believe it is severe. These are the owners I've been working
> with to identify and quantify the problem.
>
> I've collected a series of Google Street View and digital photos of
> specific locations where this happens. For those who have limited
> vision, you can find them at:
> http://hiwaay.net/~bzwilson/prius/Prius_bump_010.jpg
> http://hiwaay.net/~bzwilson/prius/Prius_bump_020.jpg
>
> Just increase the digits in the image URLs by 010 up to
"Prius_bump_200.jpg"
>
> So far, I've tried to recreate the problem with our 2010 Prius and
> have had no luck. This includes different braking experiments on snow
> and ice covered back roads as well as trying to hit just about every
> pothole, railroad crossing and manhole cover I can find. For example,
> braking with different forces on an icy road with one wheel on snow
> and ice and the other on pavement. Nothing abnormal happened as
> traction control came in and I had full steering and ABS let me come
> to a stop. The car stopped fully under control. Understand I am trying
> to recreate this problem and I'm not having any luck with our 2010 Prius.
>
> I'm a conservative engineer, which means I'm not ready to try can call
> a diagnosis. It is still under investigation. However, this is what
> those who I've been working with have reported:
>
> 1) specific road defects - it has been in one case cleared by repaving
> the road
> 2) inconsistent - it doesn't always happen but variable, seemingly
> random times, the first time being a mixture of surprise and alarm
> 3) harder pedal pressure - the car stops abruptly, by mashing the
> pedal right away, the car comes to almost an instant stop to extent of
> surprising passengers
> 4) slow speeds - 50% report it under 20 mph
>
> The Prius braking system is a fairly complex system including a
> dedicated computer, multiple hydraulic valves, yaw and accelerometer,
> brake pedal position sensor, and an active interaction with the
> transmission. The maintenance manual discusses a fairly involved
> calibration process to make sure all elements are working together.
>
> There are two other risks, sticking accelerators and even a Steve Woz
> report about the cruise control. The accelerator problem has two
> causes, the CTC part that is being modified with a shim in one recall
> and the earlier problem of floor mats catching accelerators. In both
> cases, the driver pushes the accelerator to the floor, maximum
> acceleration, and it doesn't come back. The workaround is to shift
> into "N" and then use the mechanical parking brake or remaining brake
> capacity to come to a safe stop. I've practiced both methods and know
> they work. Furthermore, our 2010 Prius cuts power when the brakes are
applied.
>
> As for the Woz report on cruise control, he eventually admitted it was
> more operator error than anything else. He 'stacks' accelerate
> commands to the cruise control computer and then the car 'takes off' and
he backs them off.
> He was also trying to make a valid point about difficulty reaching a
> help desk or complaint center including the NHTSA.
>
> There are a lot of folks willing to spread Fear Uncertainty and Doubt
> and I'm not here to minimize what appears to be a valid, intermittent,
> braking problem. The braking problem does exist even if I can't
> replicate it and it is being addressed. We just don't have a final
> resolution, yet. I can confirm others have reported credible,
> symptoms, and I'm working with them to identify where it happens and try
and replicate their results.
>
> If you have additional questions, I'll answer with what little I've
learned.
>
> Bob Wilson
>
> > Date: Thu, 4 Feb 2010 07:55:27 -0500
> > From: mrtownsend at optonline.net
> > To: tse-chat at uyahoogroups.com
> > Subject: [Quietcars] Toyota admits Prius had brake design
> >
> > One more for Toyota. They have been under the microscope lately,
> > but, I think that all auto manufacturers have had their bad streaks
> > of luck. And, because of global input of each manufacturer, for
> > example the CTS accelerator pedal assemblies that are universally
> > utilized by each man7ufacturer, Toyota may be one of many who will
> > experience the issue of unintended acceleration. This brake
> > software recall message is also one which Prius owners should check
> > out thoroughly and act if their VIN number is one of those which is
being looked into.
> >
> >
> > There have been recalls or technical service bulletins issued on
> > vehicles for as long as I can remember, and this recall situation is
> > not unique to Toyota. Ford and GM, as well as Chrysler have made
> > cars for years that been inferior in design and overall quality, and
> > they have issued recalls for engines that self-destructed due to
> > lack of lubrication or cooling. There have been transmission
> > recalls for all manufacturers. Ford had a large issue with cars
> > that were not fitted with a piece of shielding that would have
> > prevent cars from exploding if they were rear ended, and the famous
> > Ford Explorer/Mercury Mountaineer
> recall of tires and suspension is one for
> > the books as well.
> >
> > All manufacturers have done their part to fix wrongs once they were
> > found out by consumers or watchdog organizations. And, I'm glad for
> > the
> fact that
> > manufacturers and consumer groups work together on these issues.
> >
> > The sad part of this whole recall issue is this, or at least, it's
> > my humble opinion of these things. I think that many people don't
> > want to be bothered with bringing their cars in for repair because
> > it takes time away from their regular chores to do so, and most
> > often, they don't either have access to a rental car or another
> > vehicle to drive, or their communities don't have a rental facility
> > available. Please take advantage of the recalls. If it weren't for
> > consumer organizations and watchdog campaigns, this notification
> > process probably
> would have never been off the ground.
> >
> > Mike and Brent
> >
> >
> >
> > Toyota admits Prius had brake design problems Employees at Toyota
> > Motor Corp's Tsutsumi plant work at a Prius hybrid assembly line in
> > Toyota, central Japan. Toyota said its North American and Japanese
> > dealers had received several dozen complaints over what drivers
> > characterised as insufficient braking on the new Prius hybrid when
> > driving over bumpy or frozen roads.
> > REUTERS/Toyota
> > Motor Corp/Handout
> > Comments (3)
> > Yuri Kageyama
> > Tokyo - Associated Press
> > Published on Thursday, Feb. 04, 2010 3:58AM EST Last updated on
> > Thursday, Feb. 04, 2010 4:04AM EST T oyota admitted design problems
> > with the brakes in its prized Prius, adding to the catalogue of woes
> > for the world's No. 1 auto maker still reeling from a massive U.S.
> > recall involving faulty gas pedals.
> > Toyota Motor Corp. spokeswoman Ririko Takeuchi said Thursday that
> > Toyota discovered there were design problems with the antilock brake
> > system and corrected them for Prius models sold since late January,
> > including those being shipped overseas.
> > But the company said it was still investigating how to inform people
> > who had bought the gas-electric hybrid cars. Nothing was decided on
> > that front for Prius cars sold overseas, according to Toyota.
> > Complaints about braking problems in the third-generation Prius have
> > been reported in both the U.S. and Japan, combining to some 180, and
> > come amid a global recall of nearly 4.5 million other top-selling
> > vehicles for faulty gas pedals.
> > "We are investigating whether there are defects in the Prius,"
> > Toyota executive Hiroyuki Yokoyama told reporters at Toyota's Tokyo
headquarters.
> > The company gave few details of the brake flaw. A major Toyota
> > dealership in Tokyo said the auto maker had informed dealers that
> > Prius brakes can sometimes fail to work for less than a second but
> > it had
> not told owners.
> > "It is disappointing because the Prius was receiving such rave reviews,"
> > said Hiroyuki Naito, a manager at the dealership. The latest model
> > Prius hit showrooms last May.
> > The problem with the Prius - the best-selling hybrid in the world
> > and Toyota's flagship model - is a big embarrassment for the auto
> > maker in its home turf Japan and another blow in the U.S., its biggest
market.
> > In recent weeks, the auto maker had answered questions about its
> > overseas recalls for gas pedals with assurances that problems didn't
> > extend to Japanese vehicles, implying that it was doing a better job
> > with quality control in Japan.
> > The transport minister is ordering an investigation and said a
> > recall for the Prius should be considered. U.S. authorities are also
> investigating.
> > Earlier in Washington, U.S. Transportation Secretary Ray LaHood
> > startled the public with a comment, which he later retracted, that
> > Americans should park their recalled Toyotas unless driving to
> > dealers for
> accelerator repairs.
> > The popular gas-electric Prius was not part of the most recent
> > recall over sticking gas pedals in eight top-selling models
> > including the Camry that spanned the U.S., Europe and China.
> > Toyota senior managing director Takahiro Ijichi defended the
> > automaker's quality standards.
> > "We have not sacrificed the quality for the sake of saving costs,"
> > he
> said.
> > "Quality
> > is our lifeline. We want our customers to feel safe and regain their
> > trust as soon as possible."
> > Toyota for the first time gave an estimate of the costs of the U.S.
> > recall at up to $2-billion (U.S.), with $1.1-billion for the costs
> > for the repairs and $770-million to $880-million in lost sales.
> > The Prius, the world's best-selling hybrid, has been extremely
> > popular in Japan because of government incentives that made hybrids
tax-free.
> > More than 170,000 the new remodelled Prius cars were sold in Japan
> > and about 103,000 have been sold in the U.S. since May.
> > Despite snowballing problems with quality, Toyota said Thursday it
> > returned to profit in the October-December quarter because of
> > healthy sales of its green models including the Prius, and raised
> > its forecast for the fiscal year through March.
> > Net profit for October-December was about $1.7-billion. It forecast
> > a $880-million annual profit compared with its previous forecast for
> > a $2.2-billion loss.
> > Toyota also raised its full year sales outlook to 7.18 million units
> > from
> > 7.03 million.
> > The revised forecast remains lower than the 7.57 million vehicles it
> > sold last fiscal year. And it is unclear how well Toyota sales and
> > profits will hold up in coming months.
> >
> >
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