This is not a software problem. How long is your commute? The electric motor is assist. Just because you are going 10mph does not assure only motor operation. It is dependent on how much you are pressing down on the go pedal. First few miles are murder on ANY car.
Saw a Prius rear ended last night. Well, I mean I saw the result still there on roadside. A** end was accordioned up pretty good, front end undamaged. Obviously was hit in the rear pretty hard. Happened on hwy 17 in Los Gatos, Ca. Twisty, turny, hilly road. 2 lanes of fast moving traffic with no or almost no breakdown lane. Looked like it happened on a blind curve.
Now, I wonder why? Could this Prius have stalled and the driver was unable to keep going fast enuf to get out of the way? Or perhaps has the bad brakelight switch?
I know, I'm a troll here, but these are serious questions. I can tell you, if your engine dies on this road, you could be in deep doodoo.
Could've happened for any number of reasons, bad driving skills included.
And yes, we know the Prius software problem is real, but there are other vehicles that can suddenly stop. I had a 300M do the same thing - computer shut down, car died. It's dangerous no matter which vehicle it happens in.
MODERATOR /ADMINISTRATOR Find me at kirstie_h@edmunds.com - or send a private message by clicking on my name. 2015 Kia Soul, 2021 Subaru Forester (kirstie_h), 2024 GMC Sierra 1500 (mr. kirstie_h) Review your vehicle
Agreed software shutdown problems are dangerous in any car and most car manufacturers rarely have them. I think the few that Prius have had may have been over emphasized because of : (1) hybrid spotlight and (2) Toyota's high reliability standards.
“I was driving on October 31 along the highway when the engine shut down and would not restart,” writes Gerard. “The car had been at the dealership for two days in New Jersey and they didn't know what was wrong.”
After his brand new Prius shut down on the highway, Gerard’s research brought him to ConsumerAffairs.Com. “I found information on this Web site regarding 13 previous cases of the engine shutting down,” he told us.
The most confounding aspect of Gerard's Prius stalling is the age of the vehicle. “Being that this car was just shipped I would have assumed that the software issue referred to would have been resolved,” he wrote.
“Apparently that is not the case. I had to be towed off of the Interstate at night and this vehicle is only 3 weeks old.”
If it is the same problem why does it exist in a Prius sold less than a month ago? I question if they fixed or found the real problem. It seems to be elusive.
How can just one car have the problem? Wish I knew the VIN#. There is a site that Toyota set up to check if your car needed the update. Some people I know have NOT had it done until the techs are proficient in the execution.
If it is the same problem why does it exist in a Prius sold less than a month ago? I question if they fixed or found the real problem. It seems to be elusive.
--Your answer is found in the same article you quoted from... "The Prius was probably in production when the automaker discovered the software glitch..."
question: why wouldn't the dealership perform a mod / patch / update before letting the new owner drive off?
--Who knows? Ask the dealer. Maybe they assumed the same thing that the customer did --that the car was so new that the problem surely was already fixed. Maybe they simply forgot. No one is perfect.
Has anyone else had problems with the brakes on their Prius suddenly failing? My wife rear-ended a car last week in slow moving traffic (20mph) after applying the brakes, having them "pulse" several times, then the brake pedal went to the floor with no braking action. When she called the dealership, the guy said "Oh, there was a guy in here last week that said he stepped on the brake and it went to the floor and he couldn't stop".
Wondering if there is another software problem, or if the ABS system has a malfunction. Toyota is still investigating, I'll post results as they come in.
for my 2004 Prius to do the following: Engine ECM reflash; HV ECM reflash; install connector grease (on the transaxle to prevent water intrusion). Repair time approx 2 hours. Have 16,000+ miles on it and have never had a problem but better safe than sorry so I'll call Cherry Hill (NJ) Toyota, make an appointment to have the ECM System reprogrammed and will report on the results.........
Steve - The same thing happened to me yesterday. I had the same warning lights except I also had a "red" image of some sort in the screen. I had the luck to have this happen at an intersection and while I had turned on the blinking lights, cars still came up to my rear. I called Toyota on cell phone and while I had previously not been able to turn off the car or change to 'drive', 'reverse' or anything else, after a few minutes it allowed me to shift into 'D' so I could move it out of the intersection.
At Toyota, I had oil changed and the 50P recall work done.They said they had just re-programed the car. Mine is a 2004.
related to the previous "stalling" recall, because like I already declared as truth:
Car companies do NOT do recalls without knowing how to fix the problem.
PS The driver said it's a 2004 model year car, so he could have had it for two years already - not a NEW car, a TWO YEAR OLD car. And "newness" of cars has nothing to do with a car having problems. Go into any dealer service dept and look for only "old cars" and see what you find.
Oh, so now this board is NOT titled "Software Problems" rather it's titled "ONLY if your stalling issue has been diagnosed as a software problem can u post here'? Or what?
And it was a ONE year old car up until last week. No matter. ANY car whose brake pedal goes to the floor (and we have TWO reports of that just on this board alone) is a potential killer. With the complexity of the computers and software in the Prius and the fact that the brakes, as has been expounded herein, are not only fantastic but they aren't really brakes at all but rather they are hooked into the charging system and the engine management and who knows what else ... it should be obvious to someone like you who knows so much about the vehicle that the chances this is a software issue are huge - probably better that 50%.
And this is something potential buyers NEED to know about, not something that should be censored off one list.
quote heylumpofcoal-"When are you folks gonna stop drinking the Toyota Kool-Aid?"-end quote
When they stop making one of the cleanest cars on the planet, or stop making fantastically reliable and innovative cars, or stop being the world's most profitable car company, or no longer are the maker of my all time favorite car of all time, the Toyota Cressida.
And none of that will happen, so Give me KoolAid FRom Tokyo City any day !!! :shades:
If cars were eliminated from consideration because of a random brake failure here and there in the history of the car, then NO CARS WOULD be a candidate for them.
Yeah, right. I challenge you to find someone whose brake pedal has gone to the floor and caused an accident. In a car less than 2 years old. It's practically unheard of for a major malfunction like that anymore. WHY DO U THINK CARS HAVE 2 BRAKE FLUID RESERVOIRS??? It's called redundancy. I guess Toyota either skipped that step, OR PERHAPS THE SOFTWARE CONTROLS THE BRAKING SYSTEM AS ONE SYSTEM NOT TWO. DO YA THINK?
And if it's true that the S/W controls all 4 brakes as one system, well Toyota is probably violating federal safety standards. Perhaps NTSB needs to hear of this issue?
"With the complexity of the computers and software in the Prius and the fact that the brakes "
Actually all new cars are very complex and use a significant number of computers. The Lexus LS has more than 27 microprocessors.
The Prius software seems to be unfairly blown out of proportion. About the only thing different on the Prius is the HSD management between ICE and MG1 and MG2 power. And surely whoever programmed it designed some failsafes into the software
The majority, if not all of the problems have been addressed with software updates. And many of the failures are pretty low probablity because they depend on a large number of simutaneous conditions to occur.
Heyjewel said " the chances of this software issue are huge - probably better than 50%" That sounds like pure FUD to me, unless you have some cold hard facts to back it up. I would be willing to be the farm that is is much less than 1/1000 of that number, in other word more like 0.00050 probablity. Provide some facts and I will eat my humble pie.
Seriously, the Prius, as has been stated by it's zealous advocates here on these boards, is probably THE most computer and software intensive automobile ever sold to the general public. In addition, again as described herein, it has brakes that 'aren't really brakes' but rather function to help convert heat and kinetic energy into potential energy, requiring the brakes to be controlled in conjuction with the engine management and other systems.
Sure other cars have computers, but their functions are far more limited and autonomous than on the Prius. Unless a cotter pin falls out of the brake pedal linkage, what is going to cause a redundant brake system to fail completely? No, I don't have any proof for my estimate of >50%, all I have is conjecture, which is all you have. My conjecture is based on the complexity of the S/W in the Prius, how things are interconnected and interrelated ... and on the fact that I've been a software engineer for two decades, so I understand that software bugs are notorious for cropping up under untested and unusual circumstances. And the Prius has already demonstrated a proclivity for this type of software problem. That's all.
In summary - brake pedal to the floor, two cars, = serious issue.
Sure, agreed. But WHO can diagnose an issue like this into a software or not software problem?? C'mon, in the prius it very well could be software. And a loss of all braking issue does not deserve to be censored to another board. That's my point.
The point I'm making is that BRAKES FAIL ON CARS of all kinds. Hybrids, being a car which exists in that group, are not exempted from that possible failure.
The Toyota HSD system does not directly (and probably not even indirectly) manage the car's brake system in ANY way.
It's not a Hybrid which has Hybridized every single vehicle function.
Like the other poster said - modern cars have a LOT of microchips, a lot of computerized functions.
Nothing is special about the Prius HSD system which would lead to brake failure because it's a hybrid. That's just crazy talk.
Here's another - brand new 1994 Dodge Intrepid, 400 miles on it, brakes failed:
But if I'm having a braking problem, I start with the simplest possibilty first. It may very well turn out to be a software issue, although with brakes I think it's more likely to be "hardware" related.
This topic was started about a very specific software issue and really should be about things that are obviously software types of issues.
I'm hoping to get that problems & solutions topic linked over to this board so folks can discuss general Prius problems and fixes here as well
Brake Pedal Goes To The Floor When It Is Depressed: When the brakes are applied the pedal goes almost completely to the floor.
The vehicle may not stop or needs a lot of distance to come to a stop.
Possible causes:
1. Brake fluid is very low: Check the master cylinder fluid level and fill to the marked level. 2. The Master Cylinder is bad: Replace master cylinder. 3. Air in the hydraulic system: Bleed hydraulic system 4. Large leak in brake hydraulic system: Locate and repair leak
The Brakes Hardly Stop The Car Or Won't Hold It At A Stop: When the brakes are applied the car barely stops. When at a stop you need to apply a lot of pressure to keep the car stopped. Possible causes:
1. Brake fluid is very low: Check the master cylinder fluid level and fill to the marked level. 2. The Master Cylinder is bad: Replace master cylinder. 3. Air in the hydraulic system: Bleed hydraulic system 4. Brake pads and/or brake shoes are worn out: Replace the brake pads/shoes as required.
Very cool man! "two decades of software engineer". I have got you beat started programming in assembler and one of my first jobs was to define and devlop a logon Id infrastructure for a 10 cps 2741 mainframe operator console.
But then you are aware that "..as has been stated by it's zealous advocates here on these boards, is probably THE most computer and software intensive automobile ever sold to the general public. " while this might be the perception of Prius owners, it just isn't the truth. The Prius really has the same software complexity as most other current cars.
The Prius does have redundant brakes and meet all NHSTA requirements. Trouble is that apparently the normal hydralic brakes ( the redundant system) and the main software controlled brakes ( primary system) both failed; not tercerary system. The regenerative braking does not convert heat to generated power to battery charge, but is does convert the cars Kinectic energy; heat is a wasted by-product.
Just think what the world would be like without friction. Woops we wouldn't be able to walk. Okay ,just frictionless engines.
Now let';s get to where I fully agree with you " so I understand that software bugs are notorious for cropping up under untested and unusual circumstances. And the Prius has already demonstrated a proclivity for this type of software problem. That's all." I don't believe Toyota Prius used a software failure design simulator and apparently had pretty poor QA in their software debugging. I think some of these people are encountering the "untested and unusual circumstances".
I also believe battery life and longivity and replacement cost is still a crap shoot. Completely unknown.
Prius brakes are 'brake by wire'. No mechanical linkage. But is the electonic 'linkage' redundant?
From a review: "For example, in most cars, pressing the brake pedal activates the brake booster, which engages a hydraulic system that will stop the vehicle. In the Prius, by pressing the brake pedal the driver is actually activating an electric and electronic circuit that will stop the car - which is a faster, and therefore safer, way of stopping."
Faster and safer? - KoolAid drinker?
"Regenerative braking links the brakes to a generator, helping use the car's kinetic energy to recharge the battery whenever the brakes are applied."
"Department of Human Services (DHS) social worker Dawn George was driving a city-owned 1999 Dodge Caravan on North Broad Street when its brakes completely failed, according to her complaint. After careening through traffic for four blocks, George ultimately crashed at the intersection of Cecil B. Moore Avenue, critically injuring another driver and totaling both vehicles."
Hey lars, did you notice the paragraph continued after that sentence?:
"Yeah, right. I challenge you to find someone whose brake pedal has gone to the floor and caused an accident. In a car less than 2 years old. It's practically unheard of for a major malfunction like that anymore."
Enough of this already. You failed. (Though you did learn me a lesson on the weight of the Jeep Cherokee a week or so ago.)
This could be as simple as Toyota not reconnecting a brake fluid line after the service. Maybe the car had no brake fluid at the time. We may never know.
What we DO KNOW, HOWEVER, is that ANY CAR is capable of having a brake failure. Mine, Yours, Your Mom's, anyone's.
Hybridization has nothing to do with brake failure.
Sounds like a lawyer filed this complaint with the ODI. It was due to a Prius brake failure that caused an injury accident. Is it a Software Problem? I have no idea. It is a Prius problem that several owners have encountered.
DT: THE CONTACT OWNS A 2004 TOYOTA PRIUS. THE CONTACT COMPLAINED ABOUT BRAKE PROBLEMS. THE CONTACT STATED THE PEDAL HIT A STOP BEFORE LOCKING THE WHEELS TO BRAKE. THE CONTACT COMPLAINED ABOUT THE VEHICLE TO THE SERVICE DEALERSHIP AND THEY DID CHECK BRAKES ON THIS VEHICLE AS WELL AS OTHER VEHICLES OF THIS MAKE AND MODEL, BUT S IT WAS A NORMAL BRAKING PROCEDURE WITH THIS VEHICLE. THE DEALERSHIP REPLACED THE BRAKE PADS. THE CONTACT STATED WHEN HE PRESSED THE BRAKES,THERE WAS A MINIMUM BRAKING CAPABILITY IN STOP AND GO TRAFFIC. THE CONSUMER HIT A VEHICLE THAT WAS IN FRONT OF HIS VEHICLE BECAUSE HE COULD NOT STOP IT. THE CONTACT DID NOT HAVE MECHANICAL KNOWLEDGE, AND DID FEEL THIS WAS A PROBLEM, EVEN THOUGH THE DEALERSHIP STATED THERE WAS NO PROBLEM.*AK
I might add that in all my years of driving I have not had a hydraulic brake failure without plenty of warning. Usually a leaky wheel or master cylinder. I am not thrilled with brake by wire on any new car including my VW Passat.
Let's put this issue aside until someone comes up with a good explanation of how the Prius brake system works.
Some people seem to think it might work as a part of the "hybrid software system" which I think is totally ridiculous, but until someone puts something substantial on the board that proves or disproves it, why don't we stop trying to kill each other about it, Alrighty Then?
Actually if there was a brake failure I'd sue the heck out of any manufacturer. Out of the millions and millions of cars sold every year, thank goodness we can rely on our brakes. Perhaps they should have something as a safety gap like on the Flintstones. Make sure you were sneakers with lots of tread!!
"Let's put this issue aside until someone comes up with a good explanation of how the Prius brake system works. "
We know that the Prius uses regenerative braking (and we don't know if the subject vehicles were in "B" mode when the incidents occurred), and we know that the Prius has electronic - not mechanical - braking systems.
Does anyone know if the brakes report their status to the computer, that is, do they throw a software error code when they fail? That would indicate that they are tied to the main computer program.
This forum started on the hypothesis that the Prius (due to it's computer controlled multi-mode drive system) is more complex than an ordinary car. It is not a matter of the number of individual processors on a vehicle, it is the degree to which they are tied together to make the vehicle go - or not stop, in the case of brakes. I suspect that only Toyota engineers could answer the question fully, but good luck getting an answer from that source...
OK I think I found something that indicates the "hybrid software" cannot fail and thus kill the brake system:
"Hermance says that the brake system is cooperative. When you step on the brake pedal, you generate hydraulic pressure," Hermance says, "but it's not metered to the wheel cylinders until the computer decides that it needs hydraulic help." The system is designed to utilize the regenerative system as much as possible and cover the shortfall with the hydraulic brakes. In an emergency, the system will pass the hydraulic pressure on immediately.
The '04 Prius uses a new version of regenerative braking called electrically controlled braking. The system combines the benefits of ABS, electric brake distribution and brake sensors, increasing the regenerative capability of the system."
So when they say "In an emergency, the system will pass the hydraulic pressure on immediately." it sounds like to me that the computer control is bypassed in an emergency. I guess we need to know what "in an emergency" really means to completely understand what they are talking about. Do they mean "if the brakes pedal is SLAMMED down" or do they mean if the driver uses the emergency brake or it is something else?
"In the Prius, regenerative cooperative control with the hydraulic brakes includes the Electronically Controlled Brake System (ECB) that was previously adopted in the Estima hybrid. ECB has a high degree of controllability and less brake drag, thereby enabling an increase in regeneration efficiency and making a significant contribution to improving fuel efficiency."
The Prius brake system is used in the Estima hybrid in Japan. So it was not new.
So my guess from that information is that by now, as a system, it's more than likely problem-free, or they would not have used in in a second vehicle.
Comments
Now, I wonder why? Could this Prius have stalled and the driver was unable to keep going fast enuf to get out of the way? Or perhaps has the bad brakelight switch?
I know, I'm a troll here, but these are serious questions. I can tell you, if your engine dies on this road, you could be in deep doodoo.
And yes, we know the Prius software problem is real, but there are other vehicles that can suddenly stop. I had a 300M do the same thing - computer shut down, car died. It's dangerous no matter which vehicle it happens in.
kirstie_h
Roving Host
Host, Future Vehicles & Smart Shopper discussions
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Find me at kirstie_h@edmunds.com - or send a private message by clicking on my name.
2015 Kia Soul, 2021 Subaru Forester (kirstie_h), 2024 GMC Sierra 1500 (mr. kirstie_h)
Review your vehicle
Cheers,
MidCow
P.S.- Ban Prius software viruses
After his brand new Prius shut down on the highway, Gerard’s research brought him to ConsumerAffairs.Com. “I found information on this Web site regarding 13 previous cases of the engine shutting down,” he told us.
The most confounding aspect of Gerard's Prius stalling is the age of the vehicle. “Being that this car was just shipped I would have assumed that the software issue referred to would have been resolved,” he wrote.
“Apparently that is not the case. I had to be towed off of the Interstate at night and this vehicle is only 3 weeks old.”
http://www.consumeraffairs.com/news04/2005/prius_stalls4.html
--Your answer is found in the same article you quoted from...
"The Prius was probably in production when the automaker discovered the software glitch..."
--Who knows? Ask the dealer. Maybe they assumed the same thing that the customer did --that the car was so new that the problem surely was already fixed. Maybe they simply forgot. No one is perfect.
Wondering if there is another software problem, or if the ABS system has a malfunction. Toyota is still investigating, I'll post results as they come in.
At Toyota, I had oil changed and the 50P recall work done.They said they had just re-programed the car. Mine is a 2004.
This very well could be another software problem and I think you know that.
In any case, this is one heck of a problem for a brand new car, eh? Especially one which has such great brakes as have been bragged about around here.
Oh, wait, I see - the Problems and Solutions Board doesn't show up under the Hybrids->Toyota->Prius path, so that helps to hide the issue.
When are you folks gonna stop drinking the Toyota Kool-Aid?
Car companies do NOT do recalls without knowing how to fix the problem.
PS
The driver said it's a 2004 model year car, so he could have had it for two years already - not a NEW car, a TWO YEAR OLD car. And "newness" of cars has nothing to do with a car having problems. Go into any dealer service dept and look for only "old cars" and see what you find.
I think is is a spyware parasite that come in through bluetooth!
And it was a ONE year old car up until last week. No matter. ANY car whose brake pedal goes to the floor (and we have TWO reports of that just on this board alone) is a potential killer. With the complexity of the computers and software in the Prius and the fact that the brakes, as has been expounded herein, are not only fantastic but they aren't really brakes at all but rather they are hooked into the charging system and the engine management and who knows what else ... it should be obvious to someone like you who knows so much about the vehicle that the chances this is a software issue are huge - probably better that 50%.
And this is something potential buyers NEED to know about, not something that should be censored off one list.
When they stop making one of the cleanest cars on the planet, or stop making fantastically reliable and innovative cars, or stop being the world's most profitable car company, or no longer are the maker of my all time favorite car of all time, the Toyota Cressida.
And none of that will happen, so Give me KoolAid FRom Tokyo City any day !!!
Guess YOU don't need to worry about stalling or no brakes, eh?
And if it's true that the S/W controls all 4 brakes as one system, well Toyota is probably violating federal safety standards. Perhaps NTSB needs to hear of this issue?
Thanks for your participation and cooperation on this.
http://www.telegraph.co.uk/sport/main.jhtml?xml=/sport/2005/10/30/smrall30.xml&sSheet=/spo- rt/2005/10/30/ixmoto.html
http://www.thejournalnews.com/apps/pbcs.dll/article?AID=/20051028/NEWS03/510280392/1023/NE- WS07
http://www.mph-online.com/web/news/0093
http://www.car-accidents.com/pages/2005-accident_story/10-25-05.html
Any more challenges? This took about 4 minutes...
"With the complexity of the computers and software in the Prius and the fact that the brakes "
Actually all new cars are very complex and use a significant number of computers. The Lexus LS has more than 27 microprocessors.
The Prius software seems to be unfairly blown out of proportion. About the only thing different on the Prius is the HSD management between ICE and MG1 and MG2 power. And surely whoever programmed it designed some failsafes into the software
The majority, if not all of the problems have been addressed with software updates. And many of the failures are pretty low probablity because they depend on a large number of simutaneous conditions to occur.
Heyjewel said " the chances of this software issue are huge - probably better than 50%" That sounds like pure FUD to me, unless you have some cold hard facts to back it up. I would be willing to be the farm that is is much less than 1/1000 of that number, in other word more like 0.00050 probablity. Provide some facts and I will eat my humble pie.
2007 Prius GT 6-speed,
MidCow
MidCow"
Nice ride? Bet your brakes haven't failed yet:>)
Seriously, the Prius, as has been stated by it's zealous advocates here on these boards, is probably THE most computer and software intensive automobile ever sold to the general public. In addition, again as described herein, it has brakes that 'aren't really brakes' but rather function to help convert heat and kinetic energy into potential energy, requiring the brakes to be controlled in conjuction with the engine management and other systems.
Sure other cars have computers, but their functions are far more limited and autonomous than on the Prius. Unless a cotter pin falls out of the brake pedal linkage, what is going to cause a redundant brake system to fail completely? No, I don't have any proof for my estimate of >50%, all I have is conjecture, which is all you have. My conjecture is based on the complexity of the S/W in the Prius, how things are interconnected and interrelated ... and on the fact that I've been a software engineer for two decades, so I understand that software bugs are notorious for cropping up under untested and unusual circumstances. And the Prius has already demonstrated a proclivity for this type of software problem. That's all.
In summary - brake pedal to the floor, two cars, = serious issue.
Sure, agreed. But WHO can diagnose an issue like this into a software or not software problem?? C'mon, in the prius it very well could be software. And a loss of all braking issue does not deserve to be censored to another board. That's my point.
The Toyota HSD system does not directly (and probably not even indirectly) manage the car's brake system in ANY way.
It's not a Hybrid which has Hybridized every single vehicle function.
Like the other poster said - modern cars have a LOT of microchips, a lot of computerized functions.
Nothing is special about the Prius HSD system which would lead to brake failure because it's a hybrid. That's just crazy talk.
Here's another - brand new 1994 Dodge Intrepid, 400 miles on it, brakes failed:
http://www.cartalk.com/content/columns/Archive/1994/October/07.html
This topic was started about a very specific software issue and really should be about things that are obviously software types of issues.
I'm hoping to get that problems & solutions topic linked over to this board so folks can discuss general Prius problems and fixes here as well
When the brakes are applied the pedal goes almost completely to the floor.
The vehicle may not stop or needs a lot of distance to come to a stop.
Possible causes:
1. Brake fluid is very low: Check the master cylinder fluid level and fill to the marked level.
2. The Master Cylinder is bad: Replace master cylinder.
3. Air in the hydraulic system: Bleed hydraulic system
4. Large leak in brake hydraulic system: Locate and repair leak
The Brakes Hardly Stop The Car Or Won't Hold It At A Stop:
When the brakes are applied the car barely stops. When at a stop you need to apply a lot of pressure to keep the car stopped.
Possible causes:
1. Brake fluid is very low: Check the master cylinder fluid level and fill to the marked level.
2. The Master Cylinder is bad: Replace master cylinder.
3. Air in the hydraulic system: Bleed hydraulic system
4. Brake pads and/or brake shoes are worn out: Replace the brake pads/shoes as required.
Very cool man! "two decades of software engineer". I have got you beat started programming in assembler and one of my first jobs was to define and devlop a logon Id infrastructure for a 10 cps 2741 mainframe operator console.
But then you are aware that "..as has been stated by it's zealous advocates here on these boards, is probably THE most computer and software intensive automobile ever sold to the general public. " while this might be the perception
of Prius owners, it just isn't the truth. The Prius really has the same software complexity as most other current cars.
The Prius does have redundant brakes and meet all NHSTA requirements. Trouble is that apparently the normal hydralic brakes ( the redundant system) and the main software controlled brakes ( primary system) both failed; not tercerary system. The regenerative braking does not convert heat to generated power to battery charge, but is does convert the cars Kinectic energy; heat is a wasted by-product.
Just think what the world would be like without friction. Woops we wouldn't be able to walk. Okay ,just frictionless engines.
Now let';s get to where I fully agree with you " so I understand that software bugs are notorious for cropping up under untested and unusual circumstances. And the Prius has already demonstrated a proclivity for this type of software problem. That's all." I don't believe Toyota Prius used a software failure design simulator and apparently had pretty poor QA in their software debugging. I think some of these people are encountering the "untested and unusual circumstances".
I also believe battery life and longivity and replacement cost is still a crap shoot. Completely unknown.
YMMV,
MidCow
P.s. - Software engineer Outstanding!
From a review:
"For example, in most cars, pressing the brake pedal activates the brake booster, which engages a hydraulic system that will stop the vehicle. In the Prius, by pressing the brake pedal the driver is actually activating an electric and electronic circuit that will stop the car - which is a faster, and therefore safer, way of stopping."
Faster and safer? - KoolAid drinker?
"Regenerative braking links the brakes to a generator, helping use the car's kinetic energy to recharge the battery whenever the brakes are applied."
Any software involved in any of these processes?
Sorry, read my challenge again. This is an incomplete statement of the challenge.
Ans as for your post with the 4-step procedures to figure out why the brake pedal went to the floor - is that from a Toyota Prius repair manual?
I did that....the Buick crashed into a wall because they had no brake pedal pressure - that's an "accident" with airbag deployment.
Here is another one:
http://www.philadelphiaweekly.com/view.php?id=10693
"Department of Human Services (DHS) social worker Dawn George was driving a city-owned 1999 Dodge Caravan on North Broad Street when its brakes completely failed, according to her complaint. After careening through traffic for four blocks, George ultimately crashed at the intersection of Cecil B. Moore Avenue, critically injuring another driver and totaling both vehicles."
"Yeah, right. I challenge you to find someone whose brake pedal has gone to the floor and caused an accident. In a car less than 2 years old. It's practically unheard of for a major malfunction like that anymore."
Enough of this already. You failed. (Though you did learn me a lesson on the weight of the Jeep Cherokee a week or so ago.)
What we DO KNOW, HOWEVER, is that ANY CAR is capable of having a brake failure. Mine, Yours, Your Mom's, anyone's.
Hybridization has nothing to do with brake failure.
I feel like Chicken Little - "The Brakes Are Failing, The Brakes Are Failing!!!!" :shades:
(have I yet shown how silly it is to blame software for brake failures?)
DT: THE CONTACT OWNS A 2004 TOYOTA PRIUS. THE CONTACT COMPLAINED ABOUT BRAKE PROBLEMS. THE CONTACT STATED THE PEDAL HIT A STOP BEFORE LOCKING THE WHEELS TO BRAKE. THE CONTACT COMPLAINED ABOUT THE VEHICLE TO THE SERVICE DEALERSHIP AND THEY DID CHECK BRAKES ON THIS VEHICLE AS WELL AS OTHER VEHICLES OF THIS MAKE AND MODEL, BUT S IT WAS A NORMAL BRAKING PROCEDURE WITH THIS VEHICLE. THE DEALERSHIP REPLACED THE BRAKE PADS. THE CONTACT STATED WHEN HE PRESSED THE BRAKES,THERE WAS A MINIMUM BRAKING CAPABILITY IN STOP AND GO TRAFFIC. THE CONSUMER HIT A VEHICLE THAT WAS IN FRONT OF HIS VEHICLE BECAUSE HE COULD NOT STOP IT. THE CONTACT DID NOT HAVE MECHANICAL KNOWLEDGE, AND DID FEEL THIS WAS A PROBLEM, EVEN THOUGH THE DEALERSHIP STATED THERE WAS NO PROBLEM.*AK
I might add that in all my years of driving I have not had a hydraulic brake failure without plenty of warning. Usually a leaky wheel or master cylinder. I am not thrilled with brake by wire on any new car including my VW Passat.
Some people seem to think it might work as a part of the "hybrid software system" which I think is totally ridiculous, but until someone puts something substantial on the board that proves or disproves it, why don't we stop trying to kill each other about it, Alrighty Then?
Actually it is kind of a catch 22. Without brake by wire, none of the electronic stability control systems would be feasible.
We know that the Prius uses regenerative braking (and we don't know if the subject vehicles were in "B" mode when the incidents occurred), and we know that the Prius has electronic - not mechanical - braking systems.
Does anyone know if the brakes report their status to the computer, that is, do they throw a software error code when they fail? That would indicate that they are tied to the main computer program.
This forum started on the hypothesis that the Prius (due to it's computer controlled multi-mode drive system) is more complex than an ordinary car. It is not a matter of the number of individual processors on a vehicle, it is the degree to which they are tied together to make the vehicle go - or not stop, in the case of brakes.
I suspect that only Toyota engineers could answer the question fully, but good luck getting an answer from that source...
"Hermance says that the brake system is cooperative. When you step on the brake pedal, you generate hydraulic pressure," Hermance says, "but it's not metered to the wheel cylinders until the computer decides that it needs hydraulic help." The system is designed to utilize the regenerative system as much as possible and cover the shortfall with the hydraulic brakes. In an emergency, the system will pass the hydraulic pressure on immediately.
The '04 Prius uses a new version of regenerative braking called electrically controlled braking. The system combines the benefits of ABS, electric brake distribution and brake sensors, increasing the regenerative capability of the system."
So when they say "In an emergency, the system will pass the hydraulic pressure on immediately." it sounds like to me that the computer control is bypassed in an emergency. I guess we need to know what "in an emergency" really means to completely understand what they are talking about. Do they mean "if the brakes pedal is SLAMMED down" or do they mean if the driver uses the emergency brake or it is something else?
from this page:
http://tinyurl.com/c9n2r
I'll keep looking for more !!!
The Prius brake system is used in the Estima hybrid in Japan. So it was not new.
So my guess from that information is that by now, as a system, it's more than likely problem-free, or they would not have used in in a second vehicle.