cyclocommuter writes "Some Toyota owners are up in arms as they suspect that accidents have been caused by some kind of glitch in the electronic computer system used in Toyotas that controls the throttle. Refusing to accept the explanation of Toyota and the federal government (it involves the driver's-side floor mat), hundreds of Toyota owners are in rebellion after a series of accidents caused by what they call 'runaway cars.' Four people have died." The article notes: "The National Highway Traffic Safety Administration has done six separate investigations of such acceleration surges in Toyotas since 2003 and found no defect in Toyota's electronics."
I'd think not.
It's called "drive by wire" technology.
I bought an '09 Civic and the thing has a sensor attached to the gas pedal instead of the traditional wire directly to a butterfly valve.
I read somewhere that if the PCM didn't think things were right, there's a failsafe "limp home" mode that trips the throttle plate to some slightly higher than idle position and disconnects the pedal and any other controls.
One of the sales guys who I met in the process of buying this car insisted that the computer controlled throttle makes it more responsive and safer. Throttle by wire IMO, is fucking with the KISS rule.
I have a friend with a car that has a drive by wire throttle, to facilitate the traction control. That car is now having a problem when accelerating. It's only at particular throttle positions, but it acts funny. My car with a good ol' fashion cable between the pedal and throttle body is very very reliable. If the cable goes, I can replace it fairly cheap. It's much more expensive to replace the more exotic parts.
If the cable goes, I can replace it fairly cheap. It's much more expensive to replace the more exotic parts.
Also, if the cable gets wet, you have a wet cable. If the leads to the potentiometer have cracked insulation and get shorted out by dirty water or contact with metal, you have a hard open throttle. I know which I'd rather have.
This is why drive-by-wire stuff is scary. Power assist is fine, but if your hydraulic power steering loses pressure you can still steer the car (even if the steering is much heavier). Vacuum-assisted braking has enough storage to last 2-3 brake pedal pushes, and after that the brakes still function even if they too are much heavier. Antilock braking is scary enough even though it's comparatively failsafe. Handing over complete control of any further automotive function to a computer is goddamn terrifying.
Throttle by wire has been proven to be extremely responsive. More importantly, it is part of a closed-loop operation, whereby the ECU can properly evaluate requested levels versus actual in pretty much everything. If the fuel line is pinched, for example, flooring it would cause devastating detonation, EXCEPT in "by wire". Once the fuel present was mismatched to the air, the ECU would force the throttle to close somewhat, regardless of pedal position. The exception is in many cases of a wide open throttle request, when some output levels like fuel overrich are ignored, and the ECU uses an internal map of what "should be going in and out, given the max power request.
It is exceedingly easy to test the Throttle Positioning Sensor in modern vehicles. In fact, your ECU probably tests idle throttle position every time you turn the key on for a while without staring the engine. The ECU will also log 'implausible signal' for TPS that get an out of range reading, or inconsistent reading throughout the range.
Note: This information was gathered while researching diagnosing my personal car, a B5 Audi S4. It is a summary, not the automotive gospel.
This sounds like people getting paid for being stupid. I do not approve, but who am I, eh?
It is exceedingly easy to test the Throttle Positioning Sensor in modern vehicles. In fact, your ECU probably tests idle throttle position every time you turn the key on for a while without staring the engine. The ECU will also log 'implausible signal' for TPS that get an out of range reading, or inconsistent reading throughout the range.
You are basically correct. I have first hand hacking experience with the drive by wire throttle because my Grand Challenge team automated a Toyota Prius for the last Grand Challenge. There are 2 completely independent signals that go from 2 independent sensors on the pedal to the computer throttle component. The signals have to move in lock step with each other or the computer will detect a fault. If a fault is detected the throttle goes completely off and the car has to be turned off and turned back on to recover.
So for the throttle to stick down both pedal sensors have to fail in the same way at the same time, which seems highly unlikely to me. Or there could be a bug in the computer control section, bus as a software engineer I can assure you that that would be impossible.;-)
"Mechanical and hydraulic systems are much better understood."
Computer aren't exactly a new-fangled technology, and most cars built after the 70's or so have had some form of by-wire throttle control (I'm speaking, of course, of electronically controlled anti-lock brake systems which, while not fully by-wire, include a by-wire system alongside the mechanical one). I always find it amazing how people can talk about computer controlled systems are not being 'not well understood' in this day and age. Not well programmed, perhaps (though the analog there would be poorly fabricated parts, a problem that was dealt with much as poorly coded systems are being dealt with now-a-days), but not well understood? Really?
This isn't a new technology, it's been around for a while in one form or another. Sure it's less mature than conventional hydraulic, but hydraulic are much less mature than banging two sticks together, doesn't make the sticks better than hydraulic. I think my signature sums it up quite nicely, just because drive-by-wire is something relatively new (50yrs of use) and hydraulic something relatively old doesn't make one better or worse than the other, that depends on how they function. If you want to compare the two systems that way be my guest, but just stating that drive-by-wire is worse because it's newer is hogwash.
Throttle by wire IMO, is fucking with the KISS rule.
To propose that somehow mechanical cables are safer because they are simpler is severely flawed.
Have you every seen how easy it is to get a mechanical throttle to get stuck? Also in a wreck the cable the throttle can become pinched, stuck at full throttle not fun. Look at the back of street/strip drag car they have emergency kill switch on the back bumper for this reason, along with wanting to kill the fuel pump.
A mechanical throttle lacks any safety controls. A simple cable is in fact simple, but it is a stupid cable.
Twice I have seen a mechanical fail.
90s Camaro SS , guy had dropped about 10k in the motor only to have the throttle get stuck, redline, broken valves.
My Saturn has become stuck more than once when it is cold, never caused an accident.
Just because you drive car,bought a car, doesn't give you divine insight on how a car works, and somehow your experience brings insight to the conversation.Spend a little time working on/ modifying a car and you will quickly discover; mechanical cables suck ass to put in and are more prone to failure!
I have to say that the decline in manual transmission driving has really diminished people's driving abilities. It's one thing that the there's an acceleration issue. It's another thing to not consider putting the car in neutral when something like this is encountered.
because everyone is always so clear headed when their vehicle suddenly accelerates for no clear reason,and\or has the time to calm down before they collide with something.
Those that drive manuals would be more clear headed because driving is an active activity where one is engaged with the machine. I don't mean to be a dick but people who drive manuals inherently understand how the fuck a car works because it is required to get the thing moving and stopped. The new generations of people who drive only automatics truly don't understand what is going on with their cars even if they had time to think clearly and then you have the people who may know but have never had to react in that way.
When you drive a manual transmission daily you will probably encounter several situations a year where "both pedals in" is required to keep you safe. Essentially anyone who has driven manual has practiced the solution to this problem. Anyone in a automatic has not. In a automatic cars you can just hit the breaks and forget about what that meant the car had to do.
So I believe the parent is correct in his assumption that manual transmissions create drivers that are better equipped to handle situations on the road than the average automatic only driver. I am not saying that every person who drives a manual is a great driver, just that they are better equipped to handle situations on the road assuming all other variables are equal.
You and the parent can believe all you want, that does not make it true.
Let us take that case that got the Toyota floormat recall started, the Lexus that was going 120MPH on a San Diego freeway before it crashed. The car was driven by an off-duty CHP patrol officer and vehicle safety inspector. He was highly trained in offensive and defensive driving tactics.
And yet he was unable to reach forward with his right hand and pull the floor mat off the pedal? And this highly trained officer did not consider turning off the ignition, or pulling the car out of gear? I call shenanigans.
In the officer's defense, the car he was driving had a push button starter instead of an old fashioned key switch. To turn the car off, you have to hold the button down for 3 seconds. The car was a loaner, so he was not familiar with it. (I wouldn't have been either)
In my eye's, Toyota's engineers built a death trap. Why didn't the ECU cut throttle when it detected the brake switch engaged? In a VW/Audi, the ECU will cut throttle if you hold down both the brake and the gas for several seconds (why on earth would any DBW system NOT do this?).
The only thing I don't understand, is why didn't he shift into neutral...
There's more to the story than what you see in the slashdot summary - don't make any uninformed assumptions.
The guy apparently did try pulling the car out of gear and into neutral, but it didn't do anything (many auto transmissions are electronically controlled and have failsafe mechanisms to prevent desctruction). He also tried shutting off the ignition - but this vehicle like many other fancy new vehicles doesn't have a key ignition. It's a button, and when pressed while driving it won't turn the engine off. Buried in the owners manual is a single sentence that essentially says that in order to turn the engine off while driving, you have to hold the button down for three seconds.
Now I've never gone 120MPH on a congested roadway, but I could only guess that when you're trying to avoid hitting anything, it's not a simple task to 'reach down and pull the floor mat off the pedal'
Although recently I had the accelerator pedal stick to the floor on a 2009 F-350 diesel. It happened as I was accelerating from a complete stop. I immediately pressed the brake to the floor which prevented me from shortening the wheelbase of the Civic in front of me, but with 650 lb-ft of torque it was still accelerating. I was able to lift the accelerator with my foot and bring it back up.
Even if you don't consciously "understand" it, you do habitually clutch when braking to a stop. If you didn't, the engine would go out at every red-light.
It's not a stretch to imagine that if the engine got stuck at full throttle, you'd also brake-and-clutch, which happens to be the right thing to do anyway, whether you understand it or not.
because everyone is always so clear headed when their vehicle suddenly accelerates for no clear reason,and\or has the time to calm down before they collide with something.
Way to prove the grandparent's point!
Seriously, if my car were to accelerate without warning, the first thing I would do would be to push down the clutch. The second would be to apply the brake. And if that didn't work, I would pull the emergency brake. Meanwhile, aim for something soft without people in it.
If you can't mentally run through that four step list in a throttle malfunction, you shouldn't be driving. I mean, come on...The first two actions should be instinctual, panic or not.
As an owner of a 2009 Toyota Camry LE, I can confirm that my car will occasionally (maybe once every 30 minutes on average) start accelerating (not fast, maybe 1 mile per hour per second) for about 2.5 seconds, even when my foot is steady on the gas pedal, and even when I'm driving on a completely flat surface, with the cruise control off, and with no external forces like wind outside or gravity pulling the car up/down a hill. This absolutely has nothing to do with the floor mat because it happens when my feet are not shifting at all. I'm a test engineer and have a good sense of cause and effect, how changes on the inputs to a system affect the outputs. The next thing I'm going to do is remove the floor mat and see if it still happens.
Anytime your car starts to accelerate when you don't want it to, you can always just put the car in neutral. You have to train your brain to do this automatically and quickly, because if you start accelerating rapidly, you will also need to focus on the road and not cause an accident. My wife almost got in an accident several years ago because our old 1993 Ford Explorer had a sticky gas pedal. We've since gotten rid of that clunker (thank goodness), but when it was happened I told her it was important for her to train her "muscle memory" to put the car in neutral. Many people who don't know how to drive a manual transmission also don't ever use the neutral on their automatic transmission vehicles.
Are you asking us questions or what? I want to take those as statements of fact but it's like you're teasing us with some inappropriate punctuation or something.
So Toyota says it's floor mat. But here's something I don't understand after reading TFA... all people who had that problem (and lived to tell the tale) insist that they were braking hard as the car was accelerating. If it were really just gas pedal stuck in a floor mat, then surely applying brake would force the car to decelerate regardless?
I have owned many Prius's. I currently drive a 2010 one. Let's say that I'm in some place where the speed 85 mph is legal. I can nudge my cruise control speed lever and my speed barely goes up, say from 80 to 81.I nudge at again and again, up to 83. Then I nudge it again and the car takes off, no speed limit. Nudging the cruise speed control lever down has no effect until I've done it about 10 times or more. By then my Prius is doing 97. It's scary because it's so wrong and so out of your normal control. I tested this over and over the night I observed it.
It's scary because you don't think of things like putting the car in neutral when this happens. I am sure you can't turn the car off with the keyless power button, the only option on this model.
Braking does disable this scary cruise control effect. It is a natural response, so the problem is mitigated a great deal.
I have not seen this happen before so I think it's new to the 2010. I have the package which includes parallel parking assist and cruise control distance limiter.
Look who you're replying to. He's probably fixed it himself by now. In fact, he's probably re-wired and re-programed the whole thing to get at least 25% better mileage and acceleration by now.
So Toyota says it's floor mat. But here's something I don't understand after reading TFA... all people who had that problem (and lived to tell the tale) insist that they were braking hard as the car was accelerating. If it were really just gas pedal stuck in a floor mat, then surely applying brake would force the car to decelerate regardless?
Funny thing about the brake. It's operated in the same way as the accelerator, and located in a place where most people don't normally look while they're operating it.
This was famously the case with Audis in the early '90s. Audi, designing for the heel-to-toe autobahn driver, put the brake and accelerator pedals closer to each other than on most US-market cars. Cue a number of reports in the US from drivers screaming, "I was mashing the pedal as hard as I could, and the car just wouldn't stop! In fact, it kept going faster and faster!"
No defect was ever found (though that didn't stop the media from demonstrating it) and the problem was only reported in the US, although the same cars were sold worldwide.
The ES 350 and most other modern vehicles are equipped with power-assisted brakes, which operate by drawing vacuum power from the engine. But when an engine opens to full throttle, the vacuum drops, and after one or two pumps of the brake pedal the power assist feature disappears.
As a result, a driver would have to apply enormous pressure to the brake pedal to stop the car, and if the throttle was wide open might not be able to stop it at all, safety experts say.
"I don't think you can stop a car going 120 mph and an engine at full throttle without power assist," said Ditlow, the safety center director.
"There's a standard where you have to be able to stop the car without power-assisted brakes, but obviously I don't think it includes situations where the throttle is wide open," he added.
Drivers in other crashes also found it difficult to rein in a runaway Toyota. Guadalupe Gomez of Redwood City said he was held hostage for 20 miles on a Bay Area freeway by a 2007 Camry traveling more than 100 mph.
Gomez was unable to turn off the engine or shift into neutral and then burned out his brakes before slamming into another car and killing that driver, said attorney Louis Franecke, who represented that victim's family.
I used to have one of those "sudden acceleration" Audi 5000's (1979). It happened to me once and I figured out exactly what happened within five minutes. It wasn't the computer or the floor mat or anything. The accelerator pedal linkage was a solid rod which ran up a few inches from the tip of the pedal, then turned left to pass behind and above the brake pedal. If you put the arch of your foot on the brake pedal, your toes could contact the accelerator rod and depress it. Even light braking action was enough to impart enormous acceleration. The harder you stomped on the brake, the more the engine overcame the braking action. The fix was to put a metal guard plate over the rod behind the brake pedal.
Hell if 8000lb UPS trucks can manage without it [power steering], a little passenger car sure can.
It depends on the design of the vehicle, specifically the caster angle.
If your angle is 0 it's pretty easy to turn the wheel. But if it's not, then turning the wheel means also lifting the vehicle higher, and that's not easy.
They use non-zero angles so that the weight of the vehicle will auto put the wheels back to straight. It makes it much easier to drive long distances if the wheel "likes" to be straight.
And again, nothing was ever found to be wrong with the cars. Seems most of the drivers were used to American cars, and the Audi had both brake and accelerator a little to the right of the more typical position. They were pressing the accelerator instead of the brake.
Fact is, in almost all commonly available cars, if you stand on the brake and on the accelerator simultaneously, the car will go nowhere. For events to have happened as described, you'd need the simultaneous failure of two unrelated systems, which both healed themselves miraculously after the event.
Additionally, same as last time, there are a few unfortunate cases followed by a deluge of similar claims. I wonder why...
I have a 2009 Highlander Hybrid. It happened to me last week. No floormats to get in the way. Accelerator pedal returned to "home: position. The event went like this: full acceleration by me to merge into traffic and complete release of accelerator. The acceleration continued at 100% for another full second. Over 150KW of power. Now I wonder what kind of computer fault would have happened if I had pressed on the brake to compensate for the uncontrolled acceleration.....
God damn it, this again? All these "sudden acceleration" accidents are caused by morons "suddenly" putting their foot on the gas pedal. Afterwards, they say that the car accelerated by itself - and it's impossible to prove them wrong.
What's happened, in each case, is that the dealer or driver put winter floor mats, either OEM or aftermarket, on top of the regular carpeted mats. What this means is that, unlike the normal mats, they're not pinned down in any way and will slide forward. In the case of the CHP officer in the rental Lexus, the dealer slapped truck mats down on top of the "normal" Lexus mats
What happens next is easy: the mat jams the accelerator pedal. What happens after that is that people panic, do the wrong things, and plow into people in front of them.
And what happens after that is lawyers.
There's no car you can buy today where you cannot overpower the engine with full braking force. Try it: stand on the accelerator with your left foot for a while, then stand on the brake. Push both down as hard as you can; your car will slow down and stop. It won't be happy about it, but it will. The drivers in this case didn't do that: they panicked and didn't press the brakes hard enough.
Nor did the slap the car into neutral or stop the car. And yes, the car could have a gated shifter or a Prius-style stick. You can also turn the car off: even with an engine-stop button, all you need to do is holdit down. Again, in both cases it requires the driver to not panic.
There's no real way around the human factor in this. I've seen drivers who two-foot drive. I've seen drivers who, when they're presented with a scary situation, take their hands off the wheel and cover their eyes. I've been in the car when a driver's panic reaction was to flail madly at the pedals with her feet and see-saw the wheel---in that case, the car rolled. While the floor mats can create a problem, and while Toyota could fix it by mounting them a little bit higher, you'll never truly idiot-proof a car until the car drives itself.
The solution to the likes of this are systems like stability control, ABS, Volvo or Nissan's Lane Departure Control and Mercedes' and Lexus' Pre-Safe crash mitigation systems: keep the car on-course and stable, allow the driver to maintain control and, if a crash is imminent, apply full braking force, tighten the seatbelts and pre-charge the airbags. Oh, and call 911.
Try it: stand on the accelerator with your left foot for a while, then stand on the brake.
Trying to drum up business for your brake company, eh? This recession is tough all over.
I've seen drivers who, when they're presented with a scary situation, take their hands off the wheel and cover their eyes.
That's why I wear Peril Sensitive Sunglasses while driving. That way, I don't have to take my hands off the wheel to avoid seeing things that might alarm me.
My Geo Metro had the EXACT same problem. It would suddenly jump from 1mph to 1.1mph very quickly. They wouldn't admit the problem either. We figured it was due to having an odd number of cylinders.
I guarantee you this is another example of driver error in the same vein as the unintended acceleration that afflicted Audi 5000's years ago. If I'm not mistaken I think the problem in the Audi was that the position of the pedals was slightly off from what people were accustomed to causing them to think they were pressing down on the brake when they actually had the accelerator down to the floor. There have been a few other cars with similar issues.
I'm quite certain the problem with these Toyota's is similar. How in the hell could a car possible start accelerating on its own? And even if the accelerator is drive-by-wire the brakes are not and will likely never be. This means that if the owner got on the brakes hard they'd be able to slow the car. Even if the ECU didn't cut power when braking as some cars do, the engine won't be able to overpower the brakes. About the only possible culprit I see is cruise control, but again, that should be fairly easy to defeat.
The fact is that when some people panic they freeze up and are unable to do anything else. As with the Audi, they press the gas accidentally, the car lunges forward and they panic, pressing down harder on the pedal. It reminds me of what happened to my father years ago. He was teaching my sister's friend to drive. For whatever reason she got on the gas, started barreling towards a car and hit it. She freaked out and froze, her foot firmly planted on the gas. My father actually had to take her leg and lift it off the gas because she was completely unresponsive.
And the problem is that sometimes the issue isn't actually unintended acceleration but some other problem that gives that impression. I know of some cases, for example, where a transmission doesn't engage properly for whatever reason. The driver tries to accelerate but the car doesn't move, so they give it more gas. The transmission eventually does engage and the car lunges forward more aggressively than anticipated. The car may have a real problem, but the driver didn't respond to the issue appropriately.
People nowadays are far too ignorant about they drive. Some people barely know what they're driving, let alone how anything works. As part of driver training basic instruction on the mechanical operation of a car should be mandatory. This would allow drivers to better respond to problems and make them better informed when they deal with mechanics so that they don't get taken advantage of so easily. It's like Toyota's recall over the floor mats. Are drivers so oblivious that they don't notice their floor mats riding up under the pedals. It's not like those things slip under there that easily. Too many people seem to take driving as seriously as they do sitting on the sofa watching television. But they sure do manage to have quite an ego about what they drive.
Toyota has a serious problem. Have for years. It's not the floor mats.
I was driving a '98 Toyota Camry. Foot on the brake. B-R-A-K-E. Yes, I know the difference. Car in drive. Waiting for a right turn. The car revved up high. I did manage to throw it into neutral, and the engine continued to surge. Luckily I didn't hit anything. And it was pure luck.
The car did not have All-weather floor mats.
I have racing experience, and a background in Mechanical Engineering.
The reason the problem hasn't been found is that it's probably a subtle fault (like the AT&T crash back in the early '90s, or the stress concentrations in the DeHavilland Comet) and they're (by they I mean the NHTSA) probably not looking very thoroughly, due to lack of manpower. They don't do investigations of car crashes the way they do for other serious engineering failures, like plane crashes or bridge collapses.
by Anonymous Coward
on Wednesday November 04, @12:26AM (#29974012)
I had this same problem with a 1989 Jeep Cherokee in 2000. People died because of similar problems. On the internet and in court, Jeep claimed it was user error. The problem is people don't know enough about their cars to diagnose it, but it turned out to be the Throttle Position Sensor. Which would randomly rev the engine to 4000 RPM's instead of the idle of ~900 when you put it into gear. Yes, absolutely unpredictably. It was not easily duplicated for a mechanic, because when the TPS first started to go bad, it was very infrequent.
The problem is your normal routine is start the car and put it into gear almost immediately. The engine takes more time to rev noticeably past idle speed, at which time you're already moving and lost control of the car. Jeep claimed this was an unreasonable explanation, because they had an engineer sit in the car, depress the brake, put the car into gear, and then rev the engine and be unable to overpower the brakes. I found this only to be true if I were standing on the brakes, something I wasn't in practice to do, from a stop. It also overlooked the problem that once you let the car start moving, getting it stopped again was extremely difficult.
So everyone always assumes there are enough idiots out there for it to be driver error, but it happened to me, so I never trust any of the car manufacturers when this problem creeps up which it does fairly often. Also, it seems like extremely poor engineering on the manufacturer's part to fail to acknowledge this possible avenue of failure. Seems more like they are just covering their asses to avoid culpability.
I was in college at the time, and this is probably one of the more valuable lessons I've ever learned in engineering and something I think would be valuable in software engineering also. Never, ever dismiss complaining customers as morons just because its the simplest explanation especially regarding a safety issue. People actually put up with a lot. More often than not, when people complain and it is difficult to do so, there is merit to the complaint. A proper investigation is required, and a open mind, and wide imagination help determine the failure states.
Hundreds of Toyota owners?! Well, then: if a percentage of the population of Toyota owners of North Dakota are upset, by all means, everyone who has ever owned a Toyota should raise their torch and/or pitchfork!
The government & Toyota are probably right about the floor mat. But that's what recalls are for.
This is exactly what happened to me and I was heading to a cliff - 3rd gear - floored and I had the presence of mind to turn off the ignition. Seriously - I was terrified.
Picture this, you turn a corner, accelerate, change gears, and suddenly you are going around 80 Km/h with about 1 block to the edge of cliff and a 90 degree turn on a residential street with a cliff in front of you.
I had the time to turn off the ignition and jerk to a stop... BTW taking it out of gear under full acceleration is not simple either. I can hear the vacuum cleaner sound of the engine too - it was crazy. However, when the engine red-lines - it kill the accelerator for a second and then lets it restart... grabbing the ****ing anything with that is un-fun.
AFTER it stopped I could diagnose the problem being that the driver's side floor mat came off the hook that is supposed to hold it in place and inched up over the gas-pedal... thus couldn't un-press it until the carpet was pulled back.
Since there was a slot in the peg that holds the carpet in place, I took a handy dandy twist tie and wrapped the peg with the carpet in place preventing the carpet from EVER popping off that peg. Since then - no scary shit.
Toyota and Nissan should fix this problem - at their cost - and it should be a recall. - After all - it's a 10 cent fix - a peg that has a simple spring latch on top would fix it with no problems. Picture hanger anchors have used that technique for decades now.
How do you think the speedometer that the odometer is connected to works?
Besides, wheel radius on a car is variable and is constantly changing. This is one of the primary reasons that speedometers read fast - the car maker provides a conservative buffer to ensure that no matter what your tire wear, air pressure and wheel size are, there is a much better chance of you traveling equal to or slower than the displayed speed, as opposed to faster than the displayed speed.
My 1987 Plymouth reports speed 5mph lower than actual. I discovered this after getting two tickets, and the officer told me his radar showed 5mph faster than I was driving. Not the designers' fault, but my own since I inadvertently bought tires that were one size too big than the original stock. (shrug)
Back to Toyota:
Prius owners have been reporting over 5 years now that their cars will suddenly accelerate for no reason. I know at least one guy who said the car started moving while he was filling it with gas, so clearly not driver error. The car has a computer and the computer has a mind of its own. Now it seems that Prius tech is being applied to mainstream cars like Camrys, so what was once just a rare occurrence is becoming commonplace.
Toyota has a bad habit of denying culpability.
When midsize SUV and sedan engines started failing at only 20-30,000 miles Toyota refused to honor the engine warranty, and owners were forced to spend thousands of dollars for new engines. Toyota blamed the owners for failing to change their oil (even though owners had dealer receipts proving oil changes happened). Later-on it was discovered the engine ran hot and basically cooked the oil, hence early engine seizure, but Toyota still refused to honor the warranty. Eventually the US DOJ became involved and forced Toyota to refund customers for engine repairs, or else face a class-action lawsuit.
It appears Toyota is once-again being stubborn, and it may take legal action from the U.S. or EU to force them to do the right thing.
This is a "feature" of German cars due to a law in Germany mandating that the speedometer must NEVER read lower than real speed... even if the car has non-standard wheels and tires fitted.
Porsche and BMW exaggerate speed the most, and the theory is because owners of these cars are quite likely to upsize their rolling stock (and thus make the speedo read lower). It's annoying, but it's simply in response to a legal requirement.
Car and Driver did a test on several vehicles a bit over a year ago. GM vehicles were the most accurate... around +1 mph on average.
It might be true that some people hit the wrong pedal, but I actually owned an Audi 5000 Turbo and experienced sudden-acceleration.
I was driving down an Interstate highway in Texas, when the car suddenly began accelerating. I was on cruse control, and my feet were not touching any pedals. Since I'm comfortable at high speeds (past racer) and the weather and road were good, I was pretty calm. I put my foot behind the accelerator pedal and pulled back. It moved freely. I realized the cruse control had opened the throttle wide open.
I tapped the brakes to shut down the system. The pedal wouldn't move. I pressed hard with both feet, and could feel the arm flex, but it would not move. Realizing I had no brakes, and a wide open throttle, I hit the dash switch to shut off the cruse control. As the car slowed, the brakes slowly became operational. I noticed the turbo boost gage was now reading negative pressure. When the turbo boost was on, you could not apply the brakes.
It turns out that there was a check valve between the intake manifold and the brake booster. If it leaks/leaks, then high pressure air prevents the application of the brakes.
My belief is there was a bug in the cruse control, or it was susceptible to outside interference (trucker with hopped-up CB radio?) Combine that with the check valve issue and you have a car that could very well exhibit the behavior that 60 Minutes indicated. Those people said the car suddenly accelerated and the brakes didn't work. And that matches my experience exactly.
I contacted Audi USA, but they blew me off. The dealer didn't care either.
I'll let others argue whether this is a 'defect', but I've been cured of ever buying another Audi.
Virtually all (all that I have ever worked on) gasoline cars use the vacuum created in the intake plenum to operate the brake booster. Some cars use an electric vacuum motor to maintain the power breaks in designs where there is not a consistent vacuum or not accessibility to the plenum.
If you have a leak in your plenum or vacuum booster line, your engine should run rough and your breaks will be much harder too push.
The system will never prevent the application of the breaks, but it does mean instead of having power breaks, you are relying on the mechanical advantage of the pedal and your own leg power to stop the car. If you go back to the 60's you'll see "Power Brakes!" as an option you could add to your car.
Another option to shut down the cruise would be to put the car in neutral. If the engine continues to rev uncontrolled, it likely isn't the cruise control that is at fault.
I have experienced 3 sudden acceleration incidents. 1 was in my Fiero when the 15 year old Cruise Control vacuum got stuck (turning off the CC restore normal driving) and the 2 others, in a '87 Dodge Raider and an '06 Golf TDI we both due to floor mats not being properly installed. The velcro backing on the Dodge's mats had worn out, and the dealer threw in rubber mats on top of the stock mats in the Golf. In both cases the mats had crept forward enough to interfere with the gas pedal.
I'm not saying that there isn't a problem with any specific design, but in my personal experiences the faults have tended to center around pedal interference and/or aging mechanical devices.
PEBAAC (Score:5, Funny)
Problem exists between accelerator and chair?
Re:PEBAAC (Score:5, Insightful)
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Re:PEBAAC (Score:5, Insightful)
I have a friend with a car that has a drive by wire throttle, to facilitate the traction control. That car is now having a problem when accelerating. It's only at particular throttle positions, but it acts funny. My car with a good ol' fashion cable between the pedal and throttle body is very very reliable. If the cable goes, I can replace it fairly cheap. It's much more expensive to replace the more exotic parts.
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Re:PEBAAC (Score:5, Insightful)
If the cable goes, I can replace it fairly cheap. It's much more expensive to replace the more exotic parts.
Also, if the cable gets wet, you have a wet cable. If the leads to the potentiometer have cracked insulation and get shorted out by dirty water or contact with metal, you have a hard open throttle. I know which I'd rather have.
This is why drive-by-wire stuff is scary. Power assist is fine, but if your hydraulic power steering loses pressure you can still steer the car (even if the steering is much heavier). Vacuum-assisted braking has enough storage to last 2-3 brake pedal pushes, and after that the brakes still function even if they too are much heavier. Antilock braking is scary enough even though it's comparatively failsafe. Handing over complete control of any further automotive function to a computer is goddamn terrifying.
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Re:PEBAAC (Score:5, Informative)
Throttle by wire has been proven to be extremely responsive. More importantly, it is part of a closed-loop operation, whereby the ECU can properly evaluate requested levels versus actual in pretty much everything. If the fuel line is pinched, for example, flooring it would cause devastating detonation, EXCEPT in "by wire". Once the fuel present was mismatched to the air, the ECU would force the throttle to close somewhat, regardless of pedal position. The exception is in many cases of a wide open throttle request, when some output levels like fuel overrich are ignored, and the ECU uses an internal map of what "should be going in and out, given the max power request.
It is exceedingly easy to test the Throttle Positioning Sensor in modern vehicles. In fact, your ECU probably tests idle throttle position every time you turn the key on for a while without staring the engine. The ECU will also log 'implausible signal' for TPS that get an out of range reading, or inconsistent reading throughout the range.
Note: This information was gathered while researching diagnosing my personal car, a B5 Audi S4. It is a summary, not the automotive gospel.
This sounds like people getting paid for being stupid. I do not approve, but who am I, eh?
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Re:PEBAAC (Score:5, Interesting)
It is exceedingly easy to test the Throttle Positioning Sensor in modern vehicles. In fact, your ECU probably tests idle throttle position every time you turn the key on for a while without staring the engine. The ECU will also log 'implausible signal' for TPS that get an out of range reading, or inconsistent reading throughout the range.
You are basically correct. I have first hand hacking experience with the drive by wire throttle because my Grand Challenge team automated a Toyota Prius for the last Grand Challenge. There are 2 completely independent signals that go from 2 independent sensors on the pedal to the computer throttle component. The signals have to move in lock step with each other or the computer will detect a fault. If a fault is detected the throttle goes completely off and the car has to be turned off and turned back on to recover.
So for the throttle to stick down both pedal sensors have to fail in the same way at the same time, which seems highly unlikely to me. Or there could be a bug in the computer control section, bus as a software engineer I can assure you that that would be impossible. ;-)
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Re:PEBAAC (Score:5, Insightful)
"Mechanical and hydraulic systems are much better understood."
Computer aren't exactly a new-fangled technology, and most cars built after the 70's or so have had some form of by-wire throttle control (I'm speaking, of course, of electronically controlled anti-lock brake systems which, while not fully by-wire, include a by-wire system alongside the mechanical one). I always find it amazing how people can talk about computer controlled systems are not being 'not well understood' in this day and age. Not well programmed, perhaps (though the analog there would be poorly fabricated parts, a problem that was dealt with much as poorly coded systems are being dealt with now-a-days), but not well understood? Really?
This isn't a new technology, it's been around for a while in one form or another. Sure it's less mature than conventional hydraulic, but hydraulic are much less mature than banging two sticks together, doesn't make the sticks better than hydraulic. I think my signature sums it up quite nicely, just because drive-by-wire is something relatively new (50yrs of use) and hydraulic something relatively old doesn't make one better or worse than the other, that depends on how they function. If you want to compare the two systems that way be my guest, but just stating that drive-by-wire is worse because it's newer is hogwash.
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Re:PEBAAC (Score:5, Insightful)
Throttle by wire IMO, is fucking with the KISS rule.
To propose that somehow mechanical cables are safer because they are simpler is severely flawed.
Have you every seen how easy it is to get a mechanical throttle to get stuck? Also in a wreck the cable the throttle can become pinched, stuck at full throttle not fun. Look at the back of street/strip drag car they have emergency kill switch on the back bumper for this reason, along with wanting to kill the fuel pump.
A mechanical throttle lacks any safety controls. A simple cable is in fact simple, but it is a stupid cable.
Twice I have seen a mechanical fail.
90s Camaro SS , guy had dropped about 10k in the motor only to have the throttle get stuck, redline, broken valves.
My Saturn has become stuck more than once when it is cold, never caused an accident.
Just because you drive car,bought a car, doesn't give you divine insight on how a car works, and somehow your experience brings insight to the conversation.Spend a little time working on/ modifying a car and you will quickly discover; mechanical cables suck ass to put in and are more prone to failure!
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Put the damn thing in neutral! (Score:5, Insightful)
I have to say that the decline in manual transmission driving has really diminished people's driving abilities. It's one thing that the there's an acceleration issue. It's another thing to not consider putting the car in neutral when something like this is encountered.
Re:Put the damn thing in neutral! (Score:5, Insightful)
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Re:Put the damn thing in neutral! (Score:5, Insightful)
The case the media is portraying constantly had enough time to call 911 and ask for help.
Neither driver nor emergency responder thought of this solution that really should be second nature if you've had THAT much time to react.
Now, other cases may have been less lucky but for that specific case its kinda darwinistic.
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Re:Put the damn thing in neutral! (Score:5, Insightful)
Those that drive manuals would be more clear headed because driving is an active activity where one is engaged with the machine. I don't mean to be a dick but people who drive manuals inherently understand how the fuck a car works because it is required to get the thing moving and stopped. The new generations of people who drive only automatics truly don't understand what is going on with their cars even if they had time to think clearly and then you have the people who may know but have never had to react in that way.
When you drive a manual transmission daily you will probably encounter several situations a year where "both pedals in" is required to keep you safe. Essentially anyone who has driven manual has practiced the solution to this problem. Anyone in a automatic has not. In a automatic cars you can just hit the breaks and forget about what that meant the car had to do.
So I believe the parent is correct in his assumption that manual transmissions create drivers that are better equipped to handle situations on the road than the average automatic only driver. I am not saying that every person who drives a manual is a great driver, just that they are better equipped to handle situations on the road assuming all other variables are equal.
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Re:Put the damn thing in neutral! (Score:5, Funny)
Did you just make a computer analogy for a car discussion?
This thread is so backwards....
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Re:Put the damn thing in neutral! (Score:4, Insightful)
You and the parent can believe all you want, that does not make it true.
Let us take that case that got the Toyota floormat recall started, the Lexus that was going 120MPH on a San Diego freeway before it crashed. The car was driven by an off-duty CHP patrol officer and vehicle safety inspector. He was highly trained in offensive and defensive driving tactics.
And yet he was unable to reach forward with his right hand and pull the floor mat off the pedal? And this highly trained officer did not consider turning off the ignition, or pulling the car out of gear? I call shenanigans.
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Re:Put the damn thing in neutral! (Score:5, Insightful)
In the officer's defense, the car he was driving had a push button starter instead of an old fashioned key switch. To turn the car off, you have to hold the button down for 3 seconds. The car was a loaner, so he was not familiar with it. (I wouldn't have been either)
In my eye's, Toyota's engineers built a death trap. Why didn't the ECU cut throttle when it detected the brake switch engaged? In a VW/Audi, the ECU will cut throttle if you hold down both the brake and the gas for several seconds (why on earth would any DBW system NOT do this?).
The only thing I don't understand, is why didn't he shift into neutral...
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Re:Put the damn thing in neutral! (Score:5, Interesting)
The guy apparently did try pulling the car out of gear and into neutral, but it didn't do anything (many auto transmissions are electronically controlled and have failsafe mechanisms to prevent desctruction). He also tried shutting off the ignition - but this vehicle like many other fancy new vehicles doesn't have a key ignition. It's a button, and when pressed while driving it won't turn the engine off. Buried in the owners manual is a single sentence that essentially says that in order to turn the engine off while driving, you have to hold the button down for three seconds.
Now I've never gone 120MPH on a congested roadway, but I could only guess that when you're trying to avoid hitting anything, it's not a simple task to 'reach down and pull the floor mat off the pedal'
Although recently I had the accelerator pedal stick to the floor on a 2009 F-350 diesel. It happened as I was accelerating from a complete stop. I immediately pressed the brake to the floor which prevented me from shortening the wheelbase of the Civic in front of me, but with 650 lb-ft of torque it was still accelerating. I was able to lift the accelerator with my foot and bring it back up.
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Re:Put the damn thing in neutral! (Score:5, Insightful)
Even if you don't consciously "understand" it, you do habitually clutch when braking to a stop. If you didn't, the engine would go out at every red-light.
It's not a stretch to imagine that if the engine got stuck at full throttle, you'd also brake-and-clutch, which happens to be the right thing to do anyway, whether you understand it or not.
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Re:Put the damn thing in neutral! (Score:5, Insightful)
because everyone is always so clear headed when their vehicle suddenly accelerates for no clear reason,and\or has the time to calm down before they collide with something.
Way to prove the grandparent's point!
Seriously, if my car were to accelerate without warning, the first thing I would do would be to push down the clutch. The second would be to apply the brake. And if that didn't work, I would pull the emergency brake. Meanwhile, aim for something soft without people in it.
If you can't mentally run through that four step list in a throttle malfunction, you shouldn't be driving. I mean, come on...The first two actions should be instinctual, panic or not.
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I can confirm this problem with my 2009 Camry (Score:5, Informative)
Anytime your car starts to accelerate when you don't want it to, you can always just put the car in neutral. You have to train your brain to do this automatically and quickly, because if you start accelerating rapidly, you will also need to focus on the road and not cause an accident. My wife almost got in an accident several years ago because our old 1993 Ford Explorer had a sticky gas pedal. We've since gotten rid of that clunker (thank goodness), but when it was happened I told her it was important for her to train her "muscle memory" to put the car in neutral. Many people who don't know how to drive a manual transmission also don't ever use the neutral on their automatic transmission vehicles.
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Re:Put the damn thing in neutral! (Score:5, Funny)
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Floor mat, really? (Score:4, Interesting)
So Toyota says it's floor mat. But here's something I don't understand after reading TFA... all people who had that problem (and lived to tell the tale) insist that they were braking hard as the car was accelerating. If it were really just gas pedal stuck in a floor mat, then surely applying brake would force the car to decelerate regardless?
Re:Floor mat, really? (Score:5, Interesting)
I have owned many Prius's. I currently drive a 2010 one. Let's say that I'm in some place where the speed 85 mph is legal. I can nudge my cruise control speed lever and my speed barely goes up, say from 80 to 81.I nudge at again and again, up to 83. Then I nudge it again and the car takes off, no speed limit. Nudging the cruise speed control lever down has no effect until I've done it about 10 times or more. By then my Prius is doing 97. It's scary because it's so wrong and so out of your normal control. I tested this over and over the night I observed it.
It's scary because you don't think of things like putting the car in neutral when this happens. I am sure you can't turn the car off with the keyless power button, the only option on this model.
Braking does disable this scary cruise control effect. It is a natural response, so the problem is mitigated a great deal.
I have not seen this happen before so I think it's new to the 2010. I have the package which includes parallel parking assist and cruise control distance limiter.
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Re:Floor mat, really? (Score:5, Funny)
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Re:Reproducible testcase (Score:5, Funny)
Look who you're replying to. He's probably fixed it himself by now. In fact, he's probably re-wired and re-programed the whole thing to get at least 25% better mileage and acceleration by now.
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Re:Floor mat, really? (Score:5, Interesting)
So Toyota says it's floor mat. But here's something I don't understand after reading TFA... all people who had that problem (and lived to tell the tale) insist that they were braking hard as the car was accelerating. If it were really just gas pedal stuck in a floor mat, then surely applying brake would force the car to decelerate regardless?
Funny thing about the brake. It's operated in the same way as the accelerator, and located in a place where most people don't normally look while they're operating it.
This was famously the case with Audis in the early '90s. Audi, designing for the heel-to-toe autobahn driver, put the brake and accelerator pedals closer to each other than on most US-market cars. Cue a number of reports in the US from drivers screaming, "I was mashing the pedal as hard as I could, and the car just wouldn't stop! In fact, it kept going faster and faster!"
No defect was ever found (though that didn't stop the media from demonstrating it) and the problem was only reported in the US, although the same cars were sold worldwide.
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Re:Floor mat, really? (Score:4, Informative)
The ES 350 and most other modern vehicles are equipped with power-assisted brakes, which operate by drawing vacuum power from the engine. But when an engine opens to full throttle, the vacuum drops, and after one or two pumps of the brake pedal the power assist feature disappears.
As a result, a driver would have to apply enormous pressure to the brake pedal to stop the car, and if the throttle was wide open might not be able to stop it at all, safety experts say.
"I don't think you can stop a car going 120 mph and an engine at full throttle without power assist," said Ditlow, the safety center director.
"There's a standard where you have to be able to stop the car without power-assisted brakes, but obviously I don't think it includes situations where the throttle is wide open," he added.
Drivers in other crashes also found it difficult to rein in a runaway Toyota. Guadalupe Gomez of Redwood City said he was held hostage for 20 miles on a Bay Area freeway by a 2007 Camry traveling more than 100 mph.
Gomez was unable to turn off the engine or shift into neutral and then burned out his brakes before slamming into another car and killing that driver, said attorney Louis Franecke, who represented that victim's family.
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Re:Floor mat, really? (Score:5, Interesting)
I used to have one of those "sudden acceleration" Audi 5000's (1979). It happened to me once and I figured out exactly what happened within five minutes. It wasn't the computer or the floor mat or anything. The accelerator pedal linkage was a solid rod which ran up a few inches from the tip of the pedal, then turned left to pass behind and above the brake pedal. If you put the arch of your foot on the brake pedal, your toes could contact the accelerator rod and depress it. Even light braking action was enough to impart enormous acceleration. The harder you stomped on the brake, the more the engine overcame the braking action. The fix was to put a metal guard plate over the rod behind the brake pedal.
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Re:Floor mat, really? (Score:5, Informative)
God damn, people! break != brake
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Re:Floor mat, really? (Score:4, Informative)
Hell if 8000lb UPS trucks can manage without it [power steering], a little passenger car sure can.
It depends on the design of the vehicle, specifically the caster angle.
If your angle is 0 it's pretty easy to turn the wheel. But if it's not, then turning the wheel means also lifting the vehicle higher, and that's not easy.
They use non-zero angles so that the weight of the vehicle will auto put the wheels back to straight. It makes it much easier to drive long distances if the wheel "likes" to be straight.
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Same thing happend to Audi a few years ago (Score:5, Insightful)
Re:Same thing happend to Audi a few years ago (Score:5, Informative)
In the case of the state trooper, witnesses did report that the brakes were on fire as he went by.
I'm presuming not so much actual flames as burned up brake pads billowing smoke.
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Re:Same thing happend to Audi a few years ago (Score:5, Informative)
I have a 2009 Highlander Hybrid. It happened to me last week. No floormats to get in the way. Accelerator pedal returned to "home: position. The event went like this: full acceleration by me to merge into traffic and complete release of accelerator. The acceleration continued at 100% for another full second. Over 150KW of power. Now I wonder what kind of computer fault would have happened if I had pressed on the brake to compensate for the uncontrolled acceleration.....
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God damn it this again (Score:4, Informative)
Re:God damn it this again (Score:5, Interesting)
What's happened, in each case, is that the dealer or driver put winter floor mats, either OEM or aftermarket, on top of the regular carpeted mats. What this means is that, unlike the normal mats, they're not pinned down in any way and will slide forward. In the case of the CHP officer in the rental Lexus, the dealer slapped truck mats down on top of the "normal" Lexus mats
What happens next is easy: the mat jams the accelerator pedal. What happens after that is that people panic, do the wrong things, and plow into people in front of them.
And what happens after that is lawyers.
There's no car you can buy today where you cannot overpower the engine with full braking force. Try it: stand on the accelerator with your left foot for a while, then stand on the brake. Push both down as hard as you can; your car will slow down and stop. It won't be happy about it, but it will. The drivers in this case didn't do that: they panicked and didn't press the brakes hard enough.
Nor did the slap the car into neutral or stop the car. And yes, the car could have a gated shifter or a Prius-style stick. You can also turn the car off: even with an engine-stop button, all you need to do is holdit down. Again, in both cases it requires the driver to not panic.
There's no real way around the human factor in this. I've seen drivers who two-foot drive. I've seen drivers who, when they're presented with a scary situation, take their hands off the wheel and cover their eyes. I've been in the car when a driver's panic reaction was to flail madly at the pedals with her feet and see-saw the wheel---in that case, the car rolled. While the floor mats can create a problem, and while Toyota could fix it by mounting them a little bit higher, you'll never truly idiot-proof a car until the car drives itself.
The solution to the likes of this are systems like stability control, ABS, Volvo or Nissan's Lane Departure Control and Mercedes' and Lexus' Pre-Safe crash mitigation systems: keep the car on-course and stable, allow the driver to maintain control and, if a crash is imminent, apply full braking force, tighten the seatbelts and pre-charge the airbags. Oh, and call 911.
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Re:God damn it this again (Score:5, Funny)
Try it: stand on the accelerator with your left foot for a while, then stand on the brake.
Trying to drum up business for your brake company, eh? This recession is tough all over.
I've seen drivers who, when they're presented with a scary situation, take their hands off the wheel and cover their eyes.
That's why I wear Peril Sensitive Sunglasses while driving. That way, I don't have to take my hands off the wheel to avoid seeing things that might alarm me.
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problems with complexity (Score:5, Interesting)
F-35 joint strike fighter - 5.7 million
Boeing 787 - 6.5 million
Premium class automobile - ~ 100 million
IEEE Spectrum: "How hard should it be to stop a runaway luxury car?" http://spectrum.ieee.org/blog/computing/it/riskfactor/how-hard-should-it-be-to-stop-a-runaway-car [ieee.org]
IEEE Spectrum: "This car runs on code" http://www.spectrum.ieee.org/green-tech/advanced-cars/this-car-runs-on-code [ieee.org]
Re:problems with complexity (Score:5, Insightful)
F-22, F-35, Boeing - flown by professionals
Premium class auto driven by morons
Two different things. Different environments and different safety measures
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I have seen this... (Score:5, Funny)
My Geo Metro had the EXACT same problem. It would suddenly jump from 1mph to 1.1mph very quickly. They wouldn't admit the problem either. We figured it was due to having an odd number of cylinders.
Driver error. (Score:5, Insightful)
I guarantee you this is another example of driver error in the same vein as the unintended acceleration that afflicted Audi 5000's years ago. If I'm not mistaken I think the problem in the Audi was that the position of the pedals was slightly off from what people were accustomed to causing them to think they were pressing down on the brake when they actually had the accelerator down to the floor. There have been a few other cars with similar issues.
I'm quite certain the problem with these Toyota's is similar. How in the hell could a car possible start accelerating on its own? And even if the accelerator is drive-by-wire the brakes are not and will likely never be. This means that if the owner got on the brakes hard they'd be able to slow the car. Even if the ECU didn't cut power when braking as some cars do, the engine won't be able to overpower the brakes. About the only possible culprit I see is cruise control, but again, that should be fairly easy to defeat.
The fact is that when some people panic they freeze up and are unable to do anything else. As with the Audi, they press the gas accidentally, the car lunges forward and they panic, pressing down harder on the pedal. It reminds me of what happened to my father years ago. He was teaching my sister's friend to drive. For whatever reason she got on the gas, started barreling towards a car and hit it. She freaked out and froze, her foot firmly planted on the gas. My father actually had to take her leg and lift it off the gas because she was completely unresponsive.
And the problem is that sometimes the issue isn't actually unintended acceleration but some other problem that gives that impression. I know of some cases, for example, where a transmission doesn't engage properly for whatever reason. The driver tries to accelerate but the car doesn't move, so they give it more gas. The transmission eventually does engage and the car lunges forward more aggressively than anticipated. The car may have a real problem, but the driver didn't respond to the issue appropriately.
People nowadays are far too ignorant about they drive. Some people barely know what they're driving, let alone how anything works. As part of driver training basic instruction on the mechanical operation of a car should be mandatory. This would allow drivers to better respond to problems and make them better informed when they deal with mechanics so that they don't get taken advantage of so easily. It's like Toyota's recall over the floor mats. Are drivers so oblivious that they don't notice their floor mats riding up under the pedals. It's not like those things slip under there that easily. Too many people seem to take driving as seriously as they do sitting on the sofa watching television. But they sure do manage to have quite an ego about what they drive.
First Hand Experience (Score:5, Interesting)
I was driving a '98 Toyota Camry. Foot on the brake. B-R-A-K-E. Yes, I know the difference. Car in drive. Waiting for a right turn. The car revved up high. I did manage to throw it into neutral, and the engine continued to surge. Luckily I didn't hit anything. And it was pure luck.
The car did not have All-weather floor mats.
I have racing experience, and a background in Mechanical Engineering.
The reason the problem hasn't been found is that it's probably a subtle fault (like the AT&T crash back in the early '90s, or the stress concentrations in the DeHavilland Comet) and they're (by they I mean the NHTSA) probably not looking very thoroughly, due to lack of manpower. They don't do investigations of car crashes the way they do for other serious engineering failures, like plane crashes or bridge collapses.
Throttle Position Sensor (Score:5, Insightful)
I had this same problem with a 1989 Jeep Cherokee in 2000. People died because of similar problems. On the internet and in court, Jeep claimed it was user error. The problem is people don't know enough about their cars to diagnose it, but it turned out to be the Throttle Position Sensor. Which would randomly rev the engine to 4000 RPM's instead of the idle of ~900 when you put it into gear. Yes, absolutely unpredictably. It was not easily duplicated for a mechanic, because when the TPS first started to go bad, it was very infrequent.
The problem is your normal routine is start the car and put it into gear almost immediately. The engine takes more time to rev noticeably past idle speed, at which time you're already moving and lost control of the car. Jeep claimed this was an unreasonable explanation, because they had an engineer sit in the car, depress the brake, put the car into gear, and then rev the engine and be unable to overpower the brakes. I found this only to be true if I were standing on the brakes, something I wasn't in practice to do, from a stop. It also overlooked the problem that once you let the car start moving, getting it stopped again was extremely difficult.
So everyone always assumes there are enough idiots out there for it to be driver error, but it happened to me, so I never trust any of the car manufacturers when this problem creeps up which it does fairly often. Also, it seems like extremely poor engineering on the manufacturer's part to fail to acknowledge this possible avenue of failure. Seems more like they are just covering their asses to avoid culpability.
I was in college at the time, and this is probably one of the more valuable lessons I've ever learned in engineering and something I think would be valuable in software engineering also. Never, ever dismiss complaining customers as morons just because its the simplest explanation especially regarding a safety issue. People actually put up with a lot. More often than not, when people complain and it is difficult to do so, there is merit to the complaint. A proper investigation is required, and a open mind, and wide imagination help determine the failure states.
Well, then! (Score:5, Funny)
Hundreds of Toyota owners?! Well, then: if a percentage of the population of Toyota owners of North Dakota are upset, by all means, everyone who has ever owned a Toyota should raise their torch and/or pitchfork!
OMG - I own a Nissan Sentra and it happened to me. (Score:5, Informative)
The government & Toyota are probably right about the floor mat. But that's what recalls are for.
This is exactly what happened to me and I was heading to a cliff - 3rd gear - floored and I had the presence of mind to turn off the ignition. Seriously - I was terrified.
Picture this, you turn a corner, accelerate, change gears, and suddenly you are going around 80 Km/h with about 1 block to the edge of cliff and a 90 degree turn on a residential street with a cliff in front of you.
I had the time to turn off the ignition and jerk to a stop... BTW taking it out of gear under full acceleration is not simple either. I can hear the vacuum cleaner sound of the engine too - it was crazy. However, when the engine red-lines - it kill the accelerator for a second and then lets it restart... grabbing the ****ing anything with that is un-fun.
AFTER it stopped I could diagnose the problem being that the driver's side floor mat came off the hook that is supposed to hold it in place and inched up over the gas-pedal... thus couldn't un-press it until the carpet was pulled back.
Since there was a slot in the peg that holds the carpet in place, I took a handy dandy twist tie and wrapped the peg with the carpet in place preventing the carpet from EVER popping off that peg. Since then - no scary shit.
Toyota and Nissan should fix this problem - at their cost - and it should be a recall. - After all - it's a 10 cent fix - a peg that has a simple spring latch on top would fix it with no problems. Picture hanger anchors have used that technique for decades now.
Re:Carmakers lie (Score:5, Interesting)
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Re:Carmakers lie (Score:5, Informative)
How do you think the speedometer that the odometer is connected to works?
Besides, wheel radius on a car is variable and is constantly changing. This is one of the primary reasons that speedometers read fast - the car maker provides a conservative buffer to ensure that no matter what your tire wear, air pressure and wheel size are, there is a much better chance of you traveling equal to or slower than the displayed speed, as opposed to faster than the displayed speed.
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Re:Carmakers lie (Score:5, Informative)
My 1987 Plymouth reports speed 5mph lower than actual. I discovered this after getting two tickets, and the officer told me his radar showed 5mph faster than I was driving. Not the designers' fault, but my own since I inadvertently bought tires that were one size too big than the original stock. (shrug)
Back to Toyota:
Prius owners have been reporting over 5 years now that their cars will suddenly accelerate for no reason. I know at least one guy who said the car started moving while he was filling it with gas, so clearly not driver error. The car has a computer and the computer has a mind of its own. Now it seems that Prius tech is being applied to mainstream cars like Camrys, so what was once just a rare occurrence is becoming commonplace.
Toyota has a bad habit of denying culpability.
When midsize SUV and sedan engines started failing at only 20-30,000 miles Toyota refused to honor the engine warranty, and owners were forced to spend thousands of dollars for new engines. Toyota blamed the owners for failing to change their oil (even though owners had dealer receipts proving oil changes happened). Later-on it was discovered the engine ran hot and basically cooked the oil, hence early engine seizure, but Toyota still refused to honor the warranty. Eventually the US DOJ became involved and forced Toyota to refund customers for engine repairs, or else face a class-action lawsuit.
It appears Toyota is once-again being stubborn, and it may take legal action from the U.S. or EU to force them to do the right thing.
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Re:Carmakers lie (Score:5, Interesting)
This is a "feature" of German cars due to a law in Germany mandating that the speedometer must NEVER read lower than real speed... even if the car has non-standard wheels and tires fitted.
Porsche and BMW exaggerate speed the most, and the theory is because owners of these cars are quite likely to upsize their rolling stock (and thus make the speedo read lower). It's annoying, but it's simply in response to a legal requirement.
Car and Driver did a test on several vehicles a bit over a year ago. GM vehicles were the most accurate... around +1 mph on average.
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My sudden-acceleration Audi experience (Score:5, Informative)
The Audi 5000S was never defective...
It might be true that some people hit the wrong pedal, but I actually owned an Audi 5000 Turbo and experienced sudden-acceleration.
I was driving down an Interstate highway in Texas, when the car suddenly began accelerating. I was on cruse control, and my feet were not touching any pedals. Since I'm comfortable at high speeds (past racer) and the weather and road were good, I was pretty calm. I put my foot behind the accelerator pedal and pulled back. It moved freely. I realized the cruse control had opened the throttle wide open.
I tapped the brakes to shut down the system. The pedal wouldn't move. I pressed hard with both feet, and could feel the arm flex, but it would not move. Realizing I had no brakes, and a wide open throttle, I hit the dash switch to shut off the cruse control. As the car slowed, the brakes slowly became operational. I noticed the turbo boost gage was now reading negative pressure. When the turbo boost was on, you could not apply the brakes.
It turns out that there was a check valve between the intake manifold and the brake booster. If it leaks/leaks, then high pressure air prevents the application of the brakes.
My belief is there was a bug in the cruse control, or it was susceptible to outside interference (trucker with hopped-up CB radio?) Combine that with the check valve issue and you have a car that could very well exhibit the behavior that 60 Minutes indicated. Those people said the car suddenly accelerated and the brakes didn't work. And that matches my experience exactly.
I contacted Audi USA, but they blew me off. The dealer didn't care either.
I'll let others argue whether this is a 'defect', but I've been cured of ever buying another Audi.
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Re:My sudden-acceleration Audi experience (Score:5, Interesting)
Virtually all (all that I have ever worked on) gasoline cars use the vacuum created in the intake plenum to operate the brake booster. Some cars use an electric vacuum motor to maintain the power breaks in designs where there is not a consistent vacuum or not accessibility to the plenum.
If you have a leak in your plenum or vacuum booster line, your engine should run rough and your breaks will be much harder too push.
The system will never prevent the application of the breaks, but it does mean instead of having power breaks, you are relying on the mechanical advantage of the pedal and your own leg power to stop the car. If you go back to the 60's you'll see "Power Brakes!" as an option you could add to your car.
Another option to shut down the cruise would be to put the car in neutral. If the engine continues to rev uncontrolled, it likely isn't the cruise control that is at fault.
I have experienced 3 sudden acceleration incidents. 1 was in my Fiero when the 15 year old Cruise Control vacuum got stuck (turning off the CC restore normal driving) and the 2 others, in a '87 Dodge Raider and an '06 Golf TDI we both due to floor mats not being properly installed. The velcro backing on the Dodge's mats had worn out, and the dealer threw in rubber mats on top of the stock mats in the Golf. In both cases the mats had crept forward enough to interfere with the gas pedal.
I'm not saying that there isn't a problem with any specific design, but in my personal experiences the faults have tended to center around pedal interference and/or aging mechanical devices.
-Rick
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Re:This is why American cars are gaining (Score:5, Funny)
I have no idea who that is. Can you give a car analogy instead?
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