OPEN LETTER TO TOYOTA Post Throttle Control SW on the Internet for World Wide Review

Too complicated. Better to do this with just Toyota engineers, giving a big prize to whoever finds any bugs.

What we really need is just a hardwired engine-kill switch. After the car stops take a picture of the gas pedal.

-- Joe

Mark wrote in news:7e7aec70-aaca-452d-af0d- snipped-for-privacy@o16g2000vbf.googlegroups.com:

The fix is not only mechanical. Toyota is also revising its PCMs so that simultaneous brake/gas application results in the engine's power being cut back, the opposite of what happens now.

So far there is no evidence that any of the unintended acceleration incidents are due to anything more than mechanically-stuck pedals, or to pedal misapplication.

If you're that concerned about unintended acceleration, you may want to go after Ford as well. They account for 28% of all unintended acceleration incidents.

And all the left foot brakers are going to sh*t bricks!

Better solution (for future reference): Build an accelerator pedal with a microswitch attached to the pedal surface. If the driver lifts their foot, the microswitch circuit (independent of the pedal position sensor) disables the throttle plate drive system (torque motor, solenoid, or whatever they use) so that the return spring closes the throttle. You'd have to lock this out with a cruise control engage signal, but other than that, it would be redundant to the electronic controls.

Lets start at the beginning.

Until you have seen the specification for what the thing is supposed to do there is no way to tell if the hardware and code actually implement it correctly. There is every chance that at least for automatic cars in the USA the design specifications are inconsistent with sensible fail safe design. On a manual transmission you can always dip the clutch.

A reasonable introduction to how hard the problem of making reliable software and comparisons with hardware is online at CMU.

Your proposal will not work. You cannot inspect quality into software. You must first specify exactly what it is supposed to do. Most software failures are traced to incorrect, inconsistent or ambiguous requirements specification. The failure may only happen when a particular very rare set of circumstances occur - the Intel divide bug for example. Only formal mathematical proof can ensure absolute reliablity and even that is subject to interpretation - who checks the theorem provers work?

The original Intel 8087 had about a dozen bugs but until Cyrix did the formal specification to make a functional equivalent nobody had found any of them (ISTR mostly lsb errors in sin/cos).

Unlike mechanical objects and electronics which wear out with use software actually becomes more reliable with increasing age as the residual faults are uncovered. It would be interesting from an academic point of view to know whether or not Toyota use formal methods for the specification of accelerator, brake and engine management subsystems.

My instinct is that they probably do not - I had a Nissan once that decided to spontaneously immobilise itself on a busy junction at rush hour. After an engineer had reset it at the roadside it was no fault found on diagnostic test (at least that is what they told me).

You also need to know exactly what it is supposed to do in all circumstances including sensor failures and idiot user error. And there are plenty of idiot users of motor cars.

The public might regain confidence but the chances of other engineers looking over the code understanding it correctly are negligible. Even when you do understand the details of safety critical code you have to work out very carefully whether a change intended to fix one problem could possibly cause another more serious failure by slowing the response time to some other stimulus. Even the Shuttle which is truly six-sigma grade software has a known potential synchronisation fault that is not worth trying to fix and has caused launch aborts.

I presume that is how they got to the conclusion that a piece of worn hygroscopic plastic swelling is responsible for the sticky gas pedal.

I have to say reading some of the end user reports I am still more inclined to blame the nut behind the wheel rather than the engineering. OTOH I doubt they would launch such a global scale recall if there wasn't at least some truth in it.

Ignition off. You lose power steering and if you turn too far you get steering lock on which could be very embarrassing. Unclear how you do it on keyless vehicles.

Regards, Martin Brown

I wonder how many of those who had accidents caused by a stuck accelerator use left foot braking? But ever since about 1970 I've always had manual transmission vehicles, and I've only sometimes accidentally done some left foot braking when I'm driving an automatic and I reflexively try to push the clutch pedal to the floor. Of course it's actually the left side of the wide brake pedal and results in a bit of a sudden stop.

Part of the problem is people who can only think of one way to stop a car. And also one way to make it go, by flooring the accelerator. In my manual transmission vehicles, I would also release the clutch (if compression braking wasn't doing the job), and shift to a lower gear through neutral. In normal, non-aggressive driving, it should be readily apparent that the accelerator is sticking and you should have enough time to use alternate methods.

I've had a sticky accelerator and I just hooked my foot behind it and pulled it up. Mostly just because it was idling too fast, and it was usually that the carburetor cable and linkage needed lubrication, although I think it was a floor mat problem once or twice.

There have been news advisories telling people to put the car in neutral if this happens. Duh. And they advise not to shut the engine off, because (they say) you may lose steering or braking. You might lose the power assist, but there are mechanical backups (at least there used to be). And if the transmission is still in gear, the hydraulic system will probably still operate. But then I'm thinking of a manual tranny, or some automatics that have a rear pump. And also newer vehicles might have these systems under computer control, which might shut down with the ignition switch off. And of course if you turn the switch all the way, the steering lock might engage.

Yes, this is a serious problem, but I'll bet many of the accidents were the result of a failure in the most important piece of hardware in any vehicle, the "nut" behind the wheel.

Paul

Here are some interesting videos that go into some technical details:

I've also resumed the posting to include s.e.d.

Paul

Are you kidding? They will not post bills publically on the Internet before the are voted on, the REAL number of jobs lost, the total amount of US Bonds the FED is buying, REAL facts about so called global warming as well as a half dozen other "secrets," to public scrutiny or review. Why would they make Toyota do what they will not do? LOL

Left foot brakers are just practicing for their future careers in rallycross! :)

Bwahahahahaha! Approval of Toyota's product by "committee/consensus" ;-) ...Jim Thompson

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Worked for AGW? :-)

But that was just a EU committee, the IPCC. The problem with Toyota is no one wants to fail. If they admit it, they'll be jumping from windows.

Cheers

It will NEVER happen.

Another Toyota approach might be to get on board with its event data recorders. Here's a press release from Toyota from Sept. 2008 on its EDRs:

Here's what they say about their EDR program:

"A specialized tool set is required to read out data that may be contained within an EDR equipped ECU. At this time, there is only one prototype Toyota readout tool in the United States and only specially designated Toyota personnel use it. The tool set has not yet been scientifically validated, and at this time, Toyota does not have confidence that the readout reports it generates are accurate.

"Nevertheless, Toyota will access the data when it receives a written request from the National Highway Traffic Safety Administration (NHTSA) for its Special Crash Investigations program, but only with NHTSA's assurance that the vehicle owner has given written permission and no personal identifying information about the owner will be published. Toyota also will access the data to assist law enforcement in criminal investigations, when presented with a valid court order or a search warrant.

"In accordance with a 2006 NHTSA rule stating that if a manufacturer equips a vehicle with an EDR, then a tool must be made commercially available to download the data from that EDR. The compliance date is Sept. 1, 2012, the start of the 2013 model."

Sometimes it's difficult to get the automobile owner's permission to release the data to NHTSA.

Cheers, MD

very

=20

The infamous Intel FDIV bug was actually traced back to a truncated file=20 download.

And similar problems for the original 8086/8088 as well (HMA bug) which=20 was been faithfully duplicated in the 286 and 386 generations for SW=20 compatibility reasons.

My bet is that they (or their suppliers) use semi-formal methods.

Indeed, an overabundance.

I would not be so confident that it would be so fast. 6 months to a year= =20 seems more likely.

=20

Who says you turn the key all the way, oops, that's right we are dealing = with=20 "normal" people here. Power steering goes but is not that big a thing when moving more that a = few=20 mph, power brakes has a couple strokes left. Keyless ignition is a much = less=20 simple matter, and perhaps not such a bright idea.

of=20

=20

Why=20

Perhaps because Toyota IS NOT the US government. BTW have you tried = using=20 thomas.gov? The full text of HR3200 was there before it passed in the = House.

Don't the Japanese have a different ritual suicide called Harikari? Actually, now they just resign in disgrace and have degraded pensions.

AIUI, it's actually called Seppuku.

-- "Electricity is of two kinds, positive and negative. The difference is, I presume, that one comes a little more expensive, but is more durable; the other is a cheaper thing, but the moths get into it." (Stephen Leacock)

Well that is an example of the value of my comic book grade knowledge of = Japan.