How to stop a runaway Prius

Yes, all things being equal, I would find Park especially, and R easier too, as I said. Also a lot of people - me included until recently - didn't know that the throttle had to be held to get it into neutral. So if this is the case, I wonder why isn't this being more widely recommended. The Toyota site says to go to neutral first too.

 

IMHO, the "only" answer to this should be "shift to neutral while braking" (even though it does take about a second to engage neutral on a Prius). It works with any car, and shouldn't be confused by "what if I have a Maibatsu Ocelot STi EcoDrive?"

That being said, if I could have Toyota change one thing about the Prius (and similar cars), it would be the fact that tapping the power button does nothing while in gear. It should probably be changed to immediately shift to neutral while the car is moving. (Holding it for 3 seconds should still shut it down, but tapping it should do something.)

 

This was the original function of the Power button. On earlier Prius, tapping the Power button powered off the car. Problems came from this when people accidentally tapped the Power button while driving. Toyota issued a recall and reflashed to code to add the three second delay.

Sometimes you are damned if you do, and damned if you don't.

Tom

 

i still think Mr. Sikes is just an idiot. I understand that people might forget certain things or not think straight in a panic situation. But this lasted for over 20 minutes and he should have had plenty of time to come to grips with it.

However, I certainly don't rule out that it was a hoax. (Just think about the recent balloon boy news story)

I hope the feds are examining the guy closely.

• Is he late on his payments?
• Did he just buy the car recently (after the media blitz on toyota started)
• Where was he going when this happened? Does he normally drive that highway? Or did he go out of his way to find a long open road?

And for those people who said it can't be a hoax because of the brake-smell, what does that prove? I could hold my gas and brake together at the same time and it would smell after a while too.

Also - I have to admit a certain amount of confusion as to why the brake wouldn't work. After all a Prius is not a muscle car and I'm quite convinced that my Prius's drivetrain is not capable of producing enough power to override the mechanical brakes. I'm not willing to try it on mine as I don't want to damage my car, but I just don't think it would go down that way.

 

I have tested the "put it in neutral" strategy several times while accelerating to various degrees all the way up to full pedal. It has worked every time. I have not tried the power button as I don't want to find out that it might engage the parking pawl at 2 or 3 mph and cause damage.

 

Because here in the States we are lawsuit happy.

 

I turned the car off while going about 50mph or so on a straight deserted road, and it just goes silent... kind of creepy. There was a problem though, I couldnt turn it back ON. The brakes and everything worked fine, so when I got to a stoplight, I could then apply the brakes, and turn the car on, and shift into drive. So not something to do in busy traffic or someplace where you cant fully stop and restart. I do find that a little annoying. In my manual honda, I could turn it off, turn it on, and engage any gear any time I wanted at any speed I wanted. So this was a little annoying, but works as expected and promised.

 

Excellent post indeed. It is easy to Monday evening quarterbacking from the safety of the keyboard why didn't he do this or that.
Firstly, the prius is a much different car than some may have had before this, all mechanical linkages to everything, etc. And, it is a computer on wheels. Obviously, the runaway car didn't behave as it should have. The break didn't slow it down and it seems his pads were almost all worn off by the end of his ride.
People don't practice emergency conditions with their cars or at least most don't.
Maybe, with such a signal to the throttle to accelerate may overtake other commands. If that professor could simulate a single point failure, most likely there can be other points in the system that could well do the same. Uncharted territory it seems.

All the simulations by owners here works, but the, so do their cars work properly. Will any of this work when the acceleration signal is introduced? Will that signal override all others?

 

I deal with computer systems all day long. I can assure you that there *are* multiple bugs in any program...even the programming in a Prius. (There's an old programmer's joke about Sun computers having "undocumented features.") Having said that, the Prius has proven to be an uncommonly reliable and truly superior vehicle since it was introduced in the US. The second generation Prius is a masterpiece of engineering...a decade's worth of service, and a litany of perfect scores in Consumer Reports and other car ratings sources are testament to that.

Were there a fundamental problem with the Prius design or programming, it would have shown up, at least a little bit, WAY before this. You're an engineer...do a statistical analysis. Mr. Sikes was driving a 2008 Gen2 Prius...what is the statistical probability that a problem manifested on a 2 year old car would have shown up (about) 4 years ago, on your 2004 Gen2? I'm just talking about probabilities...theoreticals.

It's likely that your Prius would have started exhibiting unintended acceleration, software glitches, some time within the last 4 years, if a similar flaw existed in your system.

*If* Mr. Sikes is being truthful, then this does point to a mechanical failure. But since there is no mechanical linkage between the pedal and the accelerator circuit, it couldn't have been a faulty signal. The only conclusion is that the accelerator pedal got stuck, and told the car to accelerate...behaving correctly, but unfortunately.

There was. I have a fairly basic 2008 Gen2 Prius, even the same model year as his, and I have a brake override system. When I press on both pedals simultaneously, the car brakes.

Period.

In the 2008 Gen2 Prius which I drive, the brake pedal signal overrides the gas pedal signal completely.

I've read that he thought the car would flip in almost all reports. And, this makes no sense...neutral simply means disengaged, so the engine might "race away" but the car's gearing would be disengaged.

I simply don't believe that a man of his age (male children were taught the *basics* of cars and engineering in those days, even in California) could come to this conclusion. It's analogous to saying that by putting it in neutral it would sprout wings and fly around the LA-X terminal.

Gibberish.

This has nothing to do with respect...this has to do with the assumption that he has a brain, an IQ at least in double digits, and the basic knowledge that all men of his age are expected to possess. Heck, even my *mother* would know better than *that!*

Then, be disappointed. Some people are simply uninformed, unfamiliar with their car, and even plain stupid. I've drawn no conclusions about Mr. Sikes with this statement...but it is true.

The unintended acceleration issues in the Audi cars of the 1980s were found to stem from the stupidity of their drivers, who were stomping on the gas pedal, and expecting the car to stop. In other words, they didn't know the accelerator from the brake. This problem is *not* without precedent.

Given the decade of reliable service given by the Prius, and its flawless record until now, I tend to lean towards blaming it on the stupid and the litigious...and throw in a bit of GM/government conspiracy theory for good measure.

Is there a problem with Mr. Sikes' Prius? Maybe. Is the problem inherent to the car's design and software? Probably not.

Chuck

 

-I- think there IS a problem with Mr Sikes' car. It's the nut behind the wheel!

 

Has anyone looked at the proximity of the accelerator pedal to the brake pedal? I owned a 1999 Lexus GS prior to buying my 2006 Prius. On Both cars I have pressed the brakes and the Cars have lunched forward....I actually had to STOP Pressing the brakes and move my foot to the left to get the car to stop.

It seems my wide shoes actually hit the accelerator and the brake at the same time.....

I'm not saying this is the cause of all the braking issues but it could be the cause for some. I know when it happened in my Lexus I almost panicked, and if I had noticed my foot hitting the accelerator I would have pushed the brakes even harder causing more problems.

 

I disagree. How many times has your computer appear frozen and CTRL-ALT-DEL and other functions do not work? A runaway process or condition can always take over 100% of the processing time and cause other functions not to work or repond very slowly. Until you actually reproduce the true condition of a runaway accelerator (which ASFAIK has not yet been done) and I don't mean trying them while driving in a parking lot or at 60mph you really don't know if these techniques will work.

 

Then as a programmer you would know that the problem could have been introduced by an update later than 2004 and statistics would not mean anything. Happens all the time.

 

One would hope that safety critical software would be a tad more robust than your typical PC OS. I have written a lot of real-time control software, and I continue to design microcontroller based hardware and write firmware for these systems.

With microcontroller based control firmware, control code is usually written in a tight loop, with a watchdog timer or other technique to reset the controller if anything gets stuck. Even with a single processor, it takes a catastrophic failure before things lock up like they do on a common PC.

Tom

 

But if you do that, then the GM power steering will fail, and when you crash, the gas tank will explode

 

Of course it could...and I speculated that it could be a software problem a while back, in another thread. Even my opening sentence admitted that fact.

But, the post to which I was replying said, basically, that Mr. Sikes is not at fault, and that Toyota's products are inherently flawed. I disagree. This *could* be the case, but it's not conclusive. And, it lacks the ring of truth...if it was a fundamental design problem, whether mechanical or software based, then it should be showing up in LARGE numbers, all over.

Now, back to your statement. A software issue, since the software could be modified for each market, could definitely explain why the North American Prii are having problems, and the Euro and Japanese Prii seem not to be. But it would also imply that specific model years (with specific software updates) would be more likely to have specific problems...and there is no evidence of this. Statistically speaking, the number of incidents reported is almost insignificant...but it remains troubling, especially with the "Toyota Watch" segments on the news, every day.

Chuck

 

Not only that but 99% of PC problems are caused by new software introduced by the operator, whether it be software purchased or accidental (such as Malware). This is not possible on an embedded computer, so they tend to be rock-solid reliable.

 

+1. I was going to mention watchdog timers. Seems like some people dont understand the difference between safety critical firmware programming and your standard PC program.

I am going to have to agree with Toyota, that it is not a failure of any electronic system, just a PEBCASW error (similar to PEBCAK except steering wheel instead of keyboard ).

 

while googling prius info, i stumbled across this article from 2007:

Feds Aware of Prius Runaway Acceleration

it seems like the issue may have been present a couple of years back already, no?