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Toyota Pedal Issue Highlights Move To Electronics
cyclocommuter writes with an excerpt from a brief WSJ story on increasing electronic control of car components: "The gas pedal system used Toyota Motor Co.'s recall crisis was born from a movement in the auto industry to rely more on electronics to carry out a vehicle's most critical functions. The intricacy of such systems, which replace hoses and hydraulic fluid with computer chips and electrical sensors, has been a focus as Toyota struggled to find the cause for sudden acceleration of vehicles that led the company to halt sales of eight models this week."
Well, maybe all-electronic cars should be required to have a highly visible button labelled "Emergency Off" - I think I don't have to explain what this should (and shouldn't!) do.
The Tao of math: The numbers you can count are not the real numbers.
Summary is stupid because there's no hoses and hydraulics in any car throttle system I've seen; if it's not electronic, it's a very simple and reliable steel cable.
Story is stupid because as it admits, the electronics had nothing to do with the problem; the failure was mechanical. The exact same thing could have happened to a cable-operated system.
By all accounts I can find, the issue with the Toyota's sticky gas pedal is a MECHANICAL one - not some electrical bug.
-Bill
According to AutoBlog, the problem with these Toyotas is a mechanical part in the drive by wire pedal assembly (and so it's not really an issue with the car being drive by wire). The pivot point that the pedal rotates on has a bushing that is apparently wearing out and causing the pedal stick. I'm a little skeptical as it seems much more plausible that it would be an electrical (or software) gremlin, but that's apparently what they're blaming it on.
There is still no excuse for Toyota not coding the ECU to cut throttle when it senses that the driver has BOTH the throttle and the brakes on simultaneously. All drive by wire VW/Audis are setup this way.
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The problem with any tech is that it's nearly impossible to make it perfect. In some situations like airbags, you can make the system very simple and independent, so it's not prone to failure. But when there are scenarios that result in death, you need to be able to *shut it down* very quickly. In a car, that means literally turning the engine off.
If you can't do that in the car in question, that's insane. If it's not obvious to do so, it only highlights the life-or-death importance of good interface design, which on most cars seems to be outrageously awful. You should not reasonably have to open a manual to change the fucking clock.
citation needed. I'd say the opposite, huge number of replaced PCM modules and sensors show electronics are short lived, needlessly complex solutions offered in lieu of time tested mechanical and hydraulic ones. For example, guess what can happen if O2 sensor in exhaust system is faulty, car can drop rpm to idle then rev high in ten second pulses, very dangerous on highway. Happened to me, found myself in 4000 lbs. bucking steel bronco. Computer should not have so much control over throttle, just a small amount of mixture and timing adjustment, not complete potentially deadly control.
The latest defect in Toyota cars is quickly developing into the scandal of the 21st century. The problem started when customers of Toyota vehicles began experiencing sudden unexplained acceleration; these incidents began appearing in 2002. Over time, Toyota management claimed that the problem is the floor mat. So, the management issued a recall to replace all the floor mats.
Then, after further studying the problem, the management claimed that the throttle's pedal sometimes becomes stuck due to weather conditions. This new claim lead to the massive global recall of many vehicles sold over the past 3 years.
However, none of these explanations for the sudden acceleration has been satisfactory. Independent investigations leading to an explosion of lawsuits have determined that the problem is the electronic throttle control (ETC) — the so-called drive-by-wire mechanism that links the pedal via some cables to the fuel controller. According to a report by "Businessweek" and another report by the "Wall Street Journal", Toyota is now the defendant in 3 separate class-action lawsuits. The plaintiffs claim that the ETC is defective.
According to a report by the "New York Times" (NYT), "a few years ago, the company sent out a technical bulletin saying some cars accelerate on their own between 38 and 42 mph, and it reprogrammed the electronics with new software codes".
The NYT notes, "John Heywood, director of the Sloan Automotive Lab at MIT, said because Toyota is the only automaker having this problem, it could be something specific to its design, such as the location and integration of the electronics relay sensor."
Further, the Toyota ETC lacks an important safety mechanism: if the customer presses both the throttle pedal and the brake pedal, then the ETC should give priority to the brake. The Toyota ETC gives priority to the throttle. How can Toyota engineers commit such a gross design mistake? Common sense tells us that the brake should receive priority.
I've been around the long-haul trucking business for decades, and I hate to break it to you, but for well over 10 years now, big rigs have had electronic throttle position sensors, with a little bitty, not even particularly well-protected wire running from the pedal to the engine ECM. This is ever since Detroit Diesel came out with their electronically controlled engine in the '90s which was an amazing breakthrough in mileage and reliability. So basically every truck that we've bought or ran for over ten years has had an electronic throttle pedal, and there have been zero problems, except occasionally the TPS itself needs replaced (like every million miles or so). In this case it looks like Toyota fucked up, but that doesn't mean using electronic controls is a bad way to go, because clearly lots of things seem to be able to implement them properly, including airplanes.
'kill -9 car' works just fine!
Everything else is for n00bs.
1992 - 1995 Isuzu Trooper recall for accelerator cable stuck causing uncontrolled acceleration
2003 Ford Escape stuck throttle cables result in uncontrolled acceleration
2002 Ford Explorers investigated for stuck throttle cables in cold weather regions
1999 - 2004 Suzuki Grand Vitara, recalled due to fraying accelerator cables that result in uncontrolled acceleration and potential crash.
I guess we need to go back to the tried and true horse and buggy as these cable controls do not have a good history of reliability. But we may need to investigate the buggy brakes to ensure the can overpower the horses.
I'm not sure what happened in your bucking Bronco but O2 sensors do not control throttle position, worst case scenario would be an oscillating idle RPM as the computer adjusted fuel mixture from lean to rich. As long as your not touching the accelerator its not going to accelerate uncontrollably and will simply run like shit.
On Toyota's with this button you have to hold it down for 3 seconds before it turns off the car. In fact the long time hold has been criticized in relation to these accidents. Since you only have to touch to turn on, when you want to turn off in an emergency you also just poke at the button and nothing happens. In the panic of the moment you don't even consider trying again and holding down for a longer time.
Are you crazy!?!?
I tried that once and the skin on my arse has never been the same.
'kill -9 engine'
I don't therefore I'm not.
Before you go bashing the intelligence of the driver you should be aware of some issues.
First, the car was a rental so the driver wasn't familiar with some non-standard features of the car.
Second, the car did not have the standard key ignition switch. It has a push button on the dash that turns the engine on or off. But more importantly, when in motion the operation of the button changes. When stopped, you simply press the button and the engine turns off. But when in motion, you must hold the button down continuously for three seconds in order to turn off the engine. Presumably this is to prevent turning off the engine accidentally while driving. This three-second delay doesn't normally occur so only someone who has read the 200 page manual would know that. I imagine that in a panic situation you would press the button two or three times and then give up.
Third, the automatic transmission has a sport shifter feature. You can move the shifter in a position through a gate so that when you press forward the transmission up-shifts and when you press backward it downshifts. You cannot directly push the shifter into neutral. You have to move the shifter sideways and then up several notches to get to neutral. In an unfamiliar car and a panic situation you would try to push the shifter into neutral like most cars. Instead pushing it forward would just up-shift to a higher gear. In a panic situation, going 120 mph, it might be difficult to figure out how this non-standard transmission works -- that you have to move the shifter sideways through a gate to get to neutral.
This article (happened in Australia - linked related articles contain more information): http://www.abc.net.au/news/stories/2009/12/16/2773868.htm
describes a problem with a Ford Territory getting stuck with the cruise control actively trying to keep the vehicle at 100km/hr.
A couple of things to answer the 'this guy was idiot, I'm so clever it wouldn't have happened to me' crowd:
1. He couldn't turn off the ignition as the car won't let you do that if the car is moving.
2. He couldn't shift to neutral because the car wouldn't let him push the shift release button. (It was an automatic, so no clutch pedal.)
3. Pushing the brake wasn't helping enough to stop the car. (In the end it worked, but he had to jump on it with both feet all his adrenaline fuelled strength while pulling as hard as he could on the handbrake.)
4. The accelerator pedal only worked to speed him up, It wasn't a pedal 'sticking to the mat' issue, as the car was holding itself exactly to the speed of the cruise control.
5. The car was going too fast to just ram into a barrier or tree, etc.
6. The guy called Ford Australia (on his mobile phone), who couldn't help him and put him on hold. So then he called the police who, to their credit, cleared the road ahead and kept him calm enough to eventually get the car to stop. The total ordeal lasted 50 minutes.
7. The recording of the police call was released and played on the news and it was pretty obvious that both the guy and the police were doing everything to get the car to stop. This was not a situation where a quick two second phone call to a know-it-all Slashdotter would have solved the problem.
Anyway, I can't believe this news didn't make Slashdot when it happened a couple of months ago, as it contains considerably more information than the usual fare on this topic.
They did a test on 3 separate cars, Toyota Camry, Infiniti G37, and Roush Stage 3 Mustang to see the effective stopping power brakes at 70 mph and 100 mph, and each with no throttle and each with full throttle.
Only the Roush Mustang 3 had any real issue of slowing down with full throttle - but only at 100mph. It did stop eventually, but took 903 feet (vs about 320 feet with no throttle).
In the 100mph full throttle tests, the Camry stopped within 88 feet (vs no throttle), the Infinti within 6 feet (The Infiniti has a system that as soon as brakes get tapped the throttle closes, hence such close numbers)
So yes, for 99% of the cars on road, your brakes will overcome your engine easily.