Last post on Sep 03, 2013 at 5:22 PM
You are in the Toyota Prius
What is this discussion about?
Toyota Prius, Brakes, Hatchback, Sedan
Go to NHTSA to file a safety complaint.
Or call Monday-Friday (8 am to 8 pm ET) (888) 327-4236 TTY: (800)424-9153
#199 of 370 Re: 2007 Prius brake issues [07prius]
Feb 21, 2010 (4:50 pm)
I have a 2010 and was told by my dealer last week that my car has it--brake override--but it only kicks in at 30 mph and above.
I have not tested.
I cannot find it in my owners manual, on any Toyota official site or any other car site, in any media story, or in conversation w other Prius owners. I doubt it is true.
If anyone is sure any year Prius has brake override, please tell me. I am a bit hesitant to try it because, among other things, I do not want to damage the car.
#200 of 370 Re: 2007 Prius brake issues [roho1]
Feb 22, 2010 (12:02 pm)
Re: Post #198: "Sorry for your accident. At 35mph you are traveling at 51 feet per second. So if you were 40 feet behind him there is no way you could have stopped in time considering driver reaction time and braking distance required.
I think we all underestimate the gap we really need to stop safely."
There are too many subjective elements I think for anyone to say that there is "no way" I could have stopped in time. I have also used the calculator on http://www.csgnetwork.com/stopdistcalc.html which shows that it should have taken me 19.78 feet to stop. Nonetheless, the real issue is that after testing it as I described above I have real safety concerns, and to me it is not as important whether or not I was actually at fault in that accident - I have real concerns that I hope to have addressed, as I have a 93 mi commute and at this point do not feel safe driving my '07 Prius. BTW, I have nothing against hybrids or anything that can help save our planet - that is the whole reason I owned an '82 Mercedes 240D as I could use biodiesel in it (speaking to those who comment that there is some conspiracy against Priuses/hybrids/whatever nonsense).
#201 of 370 Re: 2007 Prius brake issues [07prius]
Feb 22, 2010 (1:54 pm)
I don't think you used that calculator correctly. To get 19.78 feet as a stopping distance you must have plugged 35 into the km/hr field. If you put 35 into the correct mph field you get a stopping distance of 51 feet which seems much more reasonable. AND...it doesn't include driver reaction time.
#202 of 370 Re: 2007 Prius brake issues [steveeast]
Feb 22, 2010 (5:56 pm)
You seem to be correct; it looks like I did use the formula incorrectly. In any case, as I mentioned, that is not the main issue I am addressing.
#203 of 370 Food for Thought
Feb 22, 2010 (6:05 pm)
Interesting message post from http://reviews.cnet.com/coupe-hatchback/2005-toyota-prius/4864-10867_7-31352228-- 2.html?ord=creationDate+desc&tag=rtcol;uo:
""High Rate of Low Speed Brake Failure in 2004-2009 Prius"
by ganderc on April 7, 2009
Pros: Great car except for the brakes.
Cons: Has a rate of low speed brake failures 31 times that of a traditionally-braked car (Corolla). Many result in rear-ending the car ahead with no injury.
Summary: I read that they redesigned the braking systems for the 2010 Prius. That appears to be Toyota's response to the fact that the U.S. Generation 2 Prius (2004-2009) has had low-speed brake failures reported to the National Highway Traffic Safety Administration (NHTSA) at 31 times the rate of such failures reported for the 2004-2009 Corolla, which of course has traditional brakes. Many of the Prius low speed brake failures were in low-speed city traffic, resulting in rear-end collisions without injury. It appears that the several computers that control the complex braking systems were too busy calculating the most efficient way to apply the brakes, and did not get around to actually applying them, until it was too late. Toyota never took responsibility for the problem, but the 2010 redesign indicates they were aware of it. Unfortunately, the NHTSA never initiated an investigation despite the extremely high rate of failures. The detailed failure reports ("complaints") are available to the public on the NHTSA website. The details are these: To April 2009, 2004-2009 Prius has received 44 complaints of low speed brake failure. 2004-2009 Corolla has received 7 complaints of such failures. Given that at least five times more Corollas than Prius were sold during 2004-2009, 44/(7/5) = 31 times the rate of brake failure for the Generation 2 Prius."
#204 of 370 Re: Spoiled Food for Thought [07prius]
Feb 27, 2010 (10:26 pm)
You quoted a message someone had posted in a review thread.
Where is the source data for this obvious nonsense?
The problem is anyone can post a message saying any nonsense they
wish. Don't bet your credibility on "ganderc on April 7, 2009" who appears
to have made something up without citing a credible source.
#205 of 370 Re: Spoiled Food for Thought [bwilson4web]
Feb 28, 2010 (4:37 am)
Here you go....
Answers to Questions About Prius and the Toyota Recalls
Q. What is the problem that led to the Prius investigations?
A. The investigations focus on a new version of the antilock brake systems on the 2010 Prius, which was introduced in Japan and the United States last spring. There have been 124 reports of problems in the United States, and 77 reports in Japan. The problem does not appear to affect earlier versions of the Prius because the brakes were redesigned for the 2010 model.
In a statement, Toyota said, “Some customers have complained of inconsistent brake feel during slow and steady application of brakes on rough or slick road surfaces when the antilock brake system (ABS) is activated in an effort to maintain tire traction. The system, in normal operation, engages and disengages rapidly (many times per second) as the control system senses and reacts to tire slippage.”
Owners are reporting that the brakes fail to work immediately when the car is on a bumpy or slippery surface, or when it drives over potholes. Toyota said Thursday that it had already identified the cause of the problem and corrected it on cars built since January. Toyota officials in Japan said Friday that the company was considering a recall of 103,000 new Priuses in the United States and 176,000 in Japan, but that a decision had not yet been made.
#206 of 370 STILL CONFUSED Re: Spoiled Food for Thought [revit]
Feb 28, 2010 (8:44 am)
BWILSON--I appreciate your effort, but your message confuses me. I was aware of the problem, which you describe, that led to a recall. I had the recall fix at my dealer on February 15 via a software flash upload. Your context seems to be of a recall yet to be announced.
Are you referring to yet another aspect of the brake complaint on 2010 Prii? I bought mine on December 12--and am generally happy with it.
Also, after listening to Mr. Toyoda's and Mr. Inabe's Congressional testimony last week, I presume that we will offered the installation of brake override--without the formalities of a recall.
#207 of 370 Re: STILL CONFUSED Re: Spoiled Food for Thought [masterpanda]
Feb 28, 2010 (10:21 am)
I called my dealer and got an appointment the same day - my computer has now been reflashed. Motivation? After feeling the symptoms just once since I got the car last August, this past Friday I felt it twice. I wish I could feel complete confidence in the upgrade, since I know that most software is not written from scratch but modified from previous versions, and I am convinced that eventually Toyota will need to fix the problem with the previous brake software in the 2005-2009 cars. Will that problem still be in my Prius?
#208 of 370 Re: STILL CONFUSED Re: Spoiled Food for Thought [masterpanda]
Mar 01, 2010 (10:16 am)
Your Prius, any Toyota, or Toyota "like" HSD systems have BTO by default. When you apply the brakes the HSD firmware is designed to enter regen mode. It is not possible to have regen active AND simultaneously DRIVE the wheels. Well, maybe the F/awd RXh or HH with 2 "drive" channels.
While it is possible to specify firmware operation that would give priority to the gas pedal position over regen braking that is NOT very probable. That would not only be a serious flaw in the design but would border on intentional, criminal, action.