Runaway car - Is this feasible?

[lionking]

http://theage.drive.com.au/motor-news/cruise-control-terror-dramatic-triple0-tape-released-20091215-kuk8.html?autostart=1

Any auto mechanics here? This guy claims that his car was stuck in cruise control and whatever he did, like stomp on the brakes, move the gear stick etc., simply didn't work - oh until he got to the end of the freeway. Ford has effectively called him a liar, and a comment from a professor in the field:


Professor John Price, former lecturer in automotive risk analysis at Monash University and consultant to the automotive industry, said he thought the incident was "extremely rare, otherwise we would have started hearing court cases about it by now".
"I can assure you companies like Ford spend a lot of effort going through every possible safety event, and this would be one of them. Something has happened here that they didn’t pick up in all their safety testing," he said.


My take? There are speed cameras on EastLink and I think he went past one speeding. What to do? Pretend he had no control and it wasn't his fault.

Yeah, probably uncharitable at this time of the year, but FWIW most radio callers think there's something fishy here.

Any thoughts?

[MRC_Hans]

Can't you always cut the ignition? Also surely, the CC does not control the brakes, so braking hard should stall the engine and stop the car.

Of course, I drive a stick so all I need is step on the clutch, should my CC try to take over ;).



Hans

[lionking]

The point about cutting the ignition is that it would then disable power steering, breaking, stability control etc, or so I understand.

[Syameese]

The point about cutting the ignition is that it would then disable power steering, breaking, stability control etc, or so I understand.

disable them yes, make the steering and brakes unuseable no. IMO this is either a complete fabrication or the person involved is such a product of the nanny state that he couldn't deal with a non perfect situation.

Of course, if it proves to be the case then it is something we need to deal with, but on the basis of the reports I have seen so far it sounds like a beat up

[383LQ4SS]

Its BS to claim nothing could be done. It could be true that he didnt try everything due to panic.

If it was a manual tranny...just push the clutch in.
If its an auto tranny...put it in nuetral

Brakes will work on all but the most powerful cars...assuming your at wide open throttle. The limited throttle of CC should be easy to overcome in nearly any car provided the brakes are in working order.

Last thing is to turn the key off (not all the way or the steering lock may lock the wheel)

I have been stuck at WOT while driving a 800hp vehicle....after completing the race...I just turned the ignition key off and coasted to a stop.

[Salerio]

The point about cutting the ignition is that it would then disable power steering, breaking, stability control etc, or so I understand.

I'm calling 'fake' on this one too. Power steering is good when you're maneuvering, but not really needed at speed, and the better power steering systems are graduated, so they don't have an effect at high speed and maximum effect at stationary to keep feedback in the steering wheel.

Same goes for the brake servos, losing the servos makes the brakes heavier, but they still work, and the hand/parking brake is purely manual anyway.

Finally these things are run from the engine, turning off the ignition won't stop the engine turning so the compressors to run all the servos will still be powered up. We had a similar case here (UK) a few years ago, the guy was on telly milking it for all it's worth then when the fuss had died down the police just quietly arrested him.

[richardm]

The point about cutting the ignition is that it would then disable power steering, breaking, stability control etc, or so I understand.

You can still steer and brake without having the engine on; it just takes more effort (a lot more, in the case of brakes, but they still work). And most cars don't have stability control anyway. So long as you kill the ignition but don't turn the key so far that the steering lock can engage, you should be fine.

Hans - it was an automatic car though; I wonder which would win if you stood on the brakes with the engine still trying to drive the wheels?

(I also don't believe this guy's story)

Edit: since I apparently type slowly - seems the brakes would win, eh?

[MRC_Hans]

Hans - it was an automatic car though; I wonder which would win if you stood on the brakes with the engine still trying to drive the wheels?

(I also don't believe this guy's story)

Edit: since I apparently type slowly - seems the brakes would win, eh?

I understant it was automatic. Still, CC can't normally apply full throttle, so brakes should win. Of course, a malfuntioning CC might open it up all the way (that is actually a quite plausible failure mode: The servo simply going all the way in on direction), but on normal cars, brakes should still be the strongest. - And there's still the ignition.

Hans

[383LQ4SS]

I understant it was automatic. Still, CC can't normally apply full throttle, so brakes should win. Of course, a malfuntioning CC might open it up all the way (that is actually a quite plausible failure mode: The servo simply going all the way in on direction), but on normal cars, brakes should still be the strongest. - And there's still the ignition.

Hans

And nuetral

[gumboot]

My take? There are speed cameras on EastLink and I think he went past one speeding. What to do? Pretend he had no control and it wasn't his fault


Doesn't cruise control just keep the car to the speed you set it at? In other words, if he got snapped speeding it means he set his cruise control too high anyway...

I suspect you've got the right of it...

[Andrew Wiggin]

I seem to recall something like this happening a year or two back, overseas. Some fella got his cruise control stuck to full throttle on the autobahn. TV footage of him going through a toll booth barrier at 100 MPH. The initial response of the car company was to deny that it could happen, but if I recall, they did eventually find a subtle fault in the software. That's not to say that a clever, non-panicked individual couldn't think of plenty of ways to stop a vehicle with a stuck throttle, but I do have some sympathy for those who aren't thinking clearly at that particular moment.

A

[a_unique_person]

According to reports.

He called Ford and the Police. They advised him to turn off the ignition, and put the car into neutral. The software over rode his ability to do so. He could not put it into neutral, nor turn off the ignition. He was talking to them and doing what they said. I can't believe it was something to dodge a fine, he nearly lost his life.

[McHrozni]

The point about cutting the ignition is that it would then disable power steering, breaking, stability control etc, or so I understand.

Brakes would still work. Some Citroën cars might have a problem with hydraulics, but all other cars are either mechanics or, more commonly, servo-assisted mechanics (like power steering), which would make the breaks harder to operate, but functional. Furthermore, hand brake is called an auxiliary brake for a reason, and it too is mechanic in all cars that I know of.
In short, there is no reason to expect these systems wouldn't work.

McHrozni

[McHrozni]

According to reports.

He called Ford and the Police. They advised him to turn off the ignition, and put the car into neutral. The software over rode his ability to do so. He could not put it into neutral, nor turn off the ignition. He was talking to them and doing what they said. I can't believe it was something to dodge a fine, he nearly lost his life.

I don't know about a particular car, but wouldn't turning the key and pulling it out kill the ignition? If the car uses a keycard rather than a key, that might be a problem, or not, depending on how that works.

McHrozni

[MRC_Hans]

Obviously, a CC can malfunction, and possible failure modes are, logically:

1) Full throttle (or as full as the CC can apply).
2) No throttle.
3) Stuck to set speed.

#3 is really the least likely, since it would require a fully functioning CC, only you could not reset it of turn it off, but I suppose a plug could fall off, disconnecting the control switches.

#2 Is the fail safe mode. I would expect that CC systems would be built so most failure mechanisms forced it to fail in this mode.

#1 Will, of course, make the car speed up. I doubt if a CC can ever apply full throttle, but this mode might be a challenge to a panicking driver. A lot of drivers have only a very foggy idea of how their vehicle functions, so the actions that appear obvious to the technical minds may not even cross their minds. However, puncing down on the brakes should be obvious to anyone qualified to drive at all (but this may not include ALL drivers).

Hans

[MRC_Hans]

According to reports.

He called Ford and the Police. They advised him to turn off the ignition, and put the car into neutral. The software over rode his ability to do so. He could not put it into neutral, nor turn off the ignition. He was talking to them and doing what they said. I can't believe it was something to dodge a fine, he nearly lost his life.

Well, I don't know the model. However, even the most fancy systems have some kind of key that can be removed, with the express purpose of immobilizing the vehicle.

- And there's still the brakes.

I'm not saying he wanted to dodge a fine, but that panic kept him from doing the right thing. He called Ford? He had the number of the technical department of Ford? Or did he just call his ford dealer? And get a salesperson who doesn't always have much idea of what goes on under the hood?

Hans

[JWideman]

Plausible, but it requires a lot of things to fail at once, and they aren't all going to just correct themselves. Any mechanic with a diagnostic computer can say "there's a fault in this, this, and this".
A more likely scenario is operator error combined with design flaw. For example, my late mother-in-law had a habit of engaging the cruise control passing mode by accident simply by the way she placed her hands on the wheel. With this particular model, having the cruise control in passing mode would keep the brake from disengaging the cruise control. The end result was that she often accelerated while going through turns. Nobody else who drove the car experienced this, and I only figured it out by carefully watching her hands.

[Shrike]

Automotive engineer here (a real one, not a Longtabber PE one).
I think the guy just panicked.
An automatic can always be put in neutral or a lower gear. Failsafe for a CC is always to sitch off, not go to full throttle.
The system is real simple: inputs are the signals from the switch (on, set, resume, off), the desired speed, the real speed, the brake light signal, and the clutch signal (or N/R/p from the auto).
Output is a signal to the throttle valve.
Another problem can just be a stuck throttle valve (in WOT), but you can always override this as well.

I seem to recall something like this happening a year or two back, overseas. Some fella got his cruise control stuck to full throttle on the autobahn. TV footage of him going through a toll booth barrier at 100 MPH. The initial response of the car company was to deny that it could happen, but if I recall, they did eventually find a subtle fault in the software. That's not to say that a clever, non-panicked individual couldn't think of plenty of ways to stop a vehicle with a stuck throttle, but I do have some sympathy for those who aren't thinking clearly at that particular moment.

A
Can you find some more on that?

[Shrike]

Brakes would still work. Some Citroën cars might have a problem with hydraulics, but all other cars are either mechanics or, more commonly, servo-assisted mechanics (like power steering), which would make the breaks harder to operate, but functional. Furthermore, hand brake is called an auxiliary brake for a reason, and it too is mechanic in all cars that I know of.
In short, there is no reason to expect these systems wouldn't work.

McHrozni
The only difference with older model Citroëns is that they used they hydraulics of the suspension and the power steering. <nitpick>
You're right, the power assistance would fail if you cut the ignition. Still, it was a freeway, so you can coast to a stop without much steering required.
You can still brake and steer, it just requires more strength.

[screensnot]

I am not familiar with the mechanical details of this vehicle.

But, I am getting more concerned about all the electronics that are used in newer vehicles.

Recently, in the US, four people died when they couldn't stop their Lexus. The driver, Mark Saylor, was a California Highway Patrolman with 19 years on the force. His wife, teenage daughter, and wife's brother were in the car. The brother made a call to 911 while the car was out of control. The call lasted 50 seconds ending with the fatal crash, so I think it's safe to assume that they had over a minute to try to regain control of the car. The official report was that the accelerator pedal got stuck on the floor mat, holding it down. The car was on loan from the dealer. Saylor had dropped his own car off for repairs earlier that day.

Three days earlier, another person had been driving the same loaner car and had the pedal get stuck on the floor mat. He said that he had to put the car in neutral, pull over, then stop the engine. After he was stopped, he discovered the floor mat holding the pedal down, cleared it, then drove the vehicle with no more problems. He says he reported the incident to the receptionist or cashier when he took it back to pick up his own vehicle.

The Lexus loaner car has a push-button to start/stop the engine (no key needed). When the vehicle is moving, you need to press and hold the start/stop button for three seconds in order to kill the engine.

The Lexus uses a drive-by-wire throttle, and has no direct linkage between the pedal and engine.

I've been told that the shifter is all electronic, and has no linkage to the transmission, but I am not sure that's true. I have worked on many electronic transmissions, and they all had mechanical linkages, while the electronics only controlled shift points while in the forward gears.

My point to all this is, when electronics are controlling so much of the vehicle, there needs to be a way for a driver to immediately override them. Especially the start/stop button. Three seconds is a long time to have to hold that button down while your car is accelerating out of control.

[GlennB]

My point to all this is, when electronics are controlling so much of the vehicle, there needs to be a way for a driver to immediately override them. Especially the start/stop button. Three seconds is a long time to have to hold that button down while your car is accelerating out of control.

Can I bookmark this for the next time I'm getting beaten up by techno-freaks in a 'totally autonomous car' debate here? :D

[MRC_Hans]

My point to all this is, when electronics are controlling so much of the vehicle, there needs to be a way for a driver to immediately override them. Especially the start/stop button. Three seconds is a long time to have to hold that button down while your car is accelerating out of control.Three seconds does seem to be a long time. OTOH, a very short reaction also has some dangers, and it MUST be a contol you are used to operate, otherwise you may not find it in time (I rarely use my horn, and when I want to, the opportunity is usually over by the time I locate the button)(On my latest car, it is back in the middle of the wheel, where it used to be ;) ).

Perhaps a two-stage function would be a good idea: Normal push on the start-stop has a delay, a really hard push (you'll be surprised how hard even a weak person can push a button in a panic) is immidiate shut-down.

Hans

[McHrozni]

The only difference with older model Citroëns is that they used they hydraulics of the suspension and the power steering. <nitpick>

They used to have hydraulic breaking as well. It's quite possible they discontinued that, though.

You're right, the power assistance would fail if you cut the ignition. Still, it was a freeway, so you can coast to a stop without much steering required.
You can still brake and steer, it just requires more strength.

Doesn't power steering progressively disengage at higher speeds anyway, or is that just an option on slightly better equipped cars? It's desirable in any event.

McHrozni

[Careyp74]

Can I bookmark this for the next time I'm getting beaten up by techno-freaks in a 'totally autonomous car' debate here? :D

I can imagine your grief, even when the article in the OP explains that all of this was happening during an emergency call to the cops, people are still calling BS.

[screensnot]

Here is a link to the Mark Saylor Lexus crash story. It includes the audio of the 911 call. *Warning* The audio clip is disturbing (to me at least).

http://www.momlogic.com/2009/09/911_call_released_in_stuck_accelerator_crash.php

[LTC8K6]

In response to some spirited debate and some odd claims on another board when the Lexus event occurred, I actually went out and did some full throttle braking tests on 2 different vehicles.

The Lexus requires you to hold the stop/start button to kill the engine when the car is in motion. The Lexus also has an odd auto shifter arrangement which can make it hard to find neutral when you are in a panic and unfamiliar with the car.

Lexus ES350 shifter in neutral. I think the driver was unfamiliar with the shifter and simply couldn't find neutral. Also, Toyota's drive by wire system apparently does not recognize brake/throttle conflicts.

http://i3.photobucket.com/albums/y66/1917-1911M/IMG_1981.jpg

At any rate, I did some full throttle braking tests on 2 different vehicles:

2008 Jeep GC 4X4 Limited 5.7L Hemi with 4 wheel discs and 5800 miles on it. Full time 4wd.

It has all the gadgets including brake assist, electronic throttle, hill start assist, hill descent control, traction control, stability control, tip start, etc. It is a CAN bus vehicle.

Tip start is similar to push-button start.

I went over to a local highway to see if my Jeep would stop at full throttle and learned a few things. I warmed the brakes up with a few stops and a little bit of dragging.

Was going downhill on an on-ramp with no one anywhere near me.

Brought it up to 60 gradually and then floored it. Let it go for a bit and then braked firmly with my left foot only, holding the throttle down with my right foot.

Braking action was strong and the Jeep slowed dramatically. It got down to about 5 mph pretty quickly, engine still roaring, but otherwise undramatic.

At about that point, the electronic throttle lamp came on and the computer dropped the engine to idle.

So, barring a brake failure, I can stop my 5.7L hemi at full throttle from highway speeds with just my left foot on the brake.

Also, the Jeep's computers recognized the throttle/brake conflict pretty quickly and set the throttle at idle.

Just did the promised light application of brake and throttle with my Jeep while moving. It did indeed recognize the conflict and try to save me. Throttle light came on and power was reduced.

At a stop, the computer allowed me to brake torque.

While moving, it intervened fairly quickly.

1996 Lumina LS 3100 V6 front wheel drive 160HP Disc/Drum ~48,000 miles - poorly maintained with an occasional anti-lock light and occasional sticking drums. Original pads and shoes. Old tires that need replacing on the front. It was about 50 degrees out, so fairly cool.

First test was with stone cold brakes. Held the car at 60 and then floored it. Braked with left foot only, holding throttle down with right foot. Very obviously going to take a while to stop. Braking action weak but clearly effective and the car did stop. Much weaker braking than I expected and much weaker than my Jeep.

Second test shortly after the first to test with heated up brakes. Much stronger braking action this time, same result. Obviously going to take longer than normal but clearly effective. Stopped quite a bit quicker this time.

Third test was to see how good the brakes were now that they had two panic stops on them. This was done with the throttle at idle from 65mph. Braking action was strong and normal.

Did a 4th full throttle test after the brakes cooled a bit. Similar results. No problem stopping.

Went about my business for a while to let the car return to normal and then did 4 more tests on the way back. These tests were to see what effect pumping the pedal had.

Held the car at 60 for a bit, then floored the throttle. Pumped the brake pedal hard 4 times and on the 5th pump I held the brakes on. Pedal was hard and high but I still seemed to have power assist. Seemed to take longer but otherwise the results were similar. I still clearly had effective brakes and they still were clearly going to stop the car, and they did.

Basically same results for the next 3 tests. I did the same thing, pump 4 times and then hold on the 5th. The brakes seemed to get more effective with some heat in them, as I would expect.

I never lost the brakes and it was always obvious that I had effective, if weaker, braking.

There was never any question in my mind that the brakes would stop the car.

Again the Lumina returned to normal quickly and the brakes acted normally after the 4 tests.

There were no apparent ill effects on the car and no warning lights. The engine temp remained normal. The transmission shifting was normal at all times.

[LTC8K6]

The key to stopping the car is to get on the brakes hard the first time and stay on them hard while you steer the vehicle and try to find N or kill the engine.

If you attempt to control the vehicle's speed with the brakes, instead of trying to stop the vehicle, the brakes are likely to overheat and fade and quit working.

[Kestrel]

The point about cutting the ignition is that it would then disable power steering, breaking, stability control etc, or so I understand.

Doesn't turning the key off also lock the steering column?

[Damien Evans]

According to reports.

He called Ford and the Police. They advised him to turn off the ignition, and put the car into neutral. The software over rode his ability to do so. He could not put it into neutral, nor turn off the ignition. He was talking to them and doing what they said. I can't believe it was something to dodge a fine, he nearly lost his life.

Sorry, but no. There is no way the software could have stopped him from turning off his engine, even if everything else he said was true, which I very much doubt.

[Careyp74]

Doesn't turning the key off also lock the steering column?

Turning it enough to cut power to the engine won't, but turning it all the way will. I believe that many, if not all cars now will not allow you to turn it all the way unless the car is in Park.

[Damien Evans]

I can imagine your grief, even when the article in the OP explains that all of this was happening during an emergency call to the cops, people are still calling BS.

People are calling BS because his story is just not plausible. Oh, and if he was on the phone there's a law he's broken right there (unless he had a handsfree system, which very few people do)

[Sir Robin Goodfellow]

It would require several unusual failures to happen at once. The shifter should always be easily pushed forward to neutral, and in most vehicles you can turn the ignition off while still in drive. The steering wheel should never lock in any key position but off. The default mode for cruise control is non-functional if any electrical problems should occur. I suppose if the cruise control circuitry somehow overheated, for example, it might cause some weird fault like non-disengagement. Still, it's a stretch to think that the cruise control could lock on and the ignition switch and a mechanical shifter linkage would fail at the same time. I guess it's possible, just very unlikely.

I agree the guy probably panicked. He may have tried to turn the key off but turned it the wrong way.

[Damien Evans]

Turning it enough to cut power to the engine won't, but turning it all the way will. I believe that many, if not all cars now will not allow you to turn it all the way unless the car is in Park.

Not all, but, yes, many, perhaps even most.

[MRC_Hans]

Doesn't turning the key off also lock the steering column?A conventional key has an intermediate position that cuts the engine but does not engage the wheel lock. SOmetimes you need to take the key out to engage it. I'm not sure about key-card systems, but I'm pretty sure any car will allow you to cut the engine without engaging the wheel lock.. A lot of things become rather tricky without it.

But yes, I heard a story about this guy who did economy driving, setting the car in neutral and cutting the engine when going down-hill (long ago, manual transmision, rear-wheel drive, you can do that), and explaining the technique to his passengers, he actually took out the key and held it up. - Came a turn in the road ....:eye-poppi

Hans

[qayak]

IThe Lexus loaner car has a push-button to start/stop the engine (no key needed). When the vehicle is moving, you need to press and hold the start/stop button for three seconds in order to kill the engine.

I don't think this is right. It takes three seconds to start the car but not to turn it off. I have one in the shop today, I will try it.

Toyota did a massive recall because of the car mat problem.

[qayak]

People are calling BS because his story is just not plausible. Oh, and if he was on the phone there's a law he's broken right there (unless he had a handsfree system, which very few people do)

Exactly! He could dial the phone but not turn off the ignition . . . right!

[screensnot]

The Lexus also has an odd auto shifter arrangement which can make it hard to find neutral when you are in a panic and unfamiliar with the car.

I agree that that Lexus shifter is a bit unusual and possibly confusing. Especially because the position closest to the "N" is not neutral, it's upshift.

But with an entire minute to think about it, you'd think they'd have figured it out. Plus, the car the Saylor dropped off for repair was also a Lexus, so I'm guessing it had the same shifter.

They also knew the road was going to end at a 'T' intersection, so I'm surprised that they would try putting it in park as a last resort.

For a while I would have bet that the Lexus electronics kept the transmission in drive, even though they tried all positions on the shifter. But, with the recent release of the statement by the guy who saved himself in the same car just three days earlier, I'm not sure anymore (that guy put it in neutral to get the car stopped).

[screensnot]

I don't think this is right. It takes three seconds to start the car but not to turn it off. I have one in the shop today, I will try it.

Toyota did a massive recall because of the car mat problem.

From what I hear, when the car is in motion (or maybe just in gear) it takes 3 seconds to shut it off. Apparently, a 'safety' feature to keep you from accidentally shutting the car off when you don't want to.

[Beerina]

The key to stopping the car is to get on the brakes hard the first time and stay on them hard while you steer the vehicle and try to find N or kill the engine.

If you attempt to control the vehicle's speed with the brakes, instead of trying to stop the vehicle, the brakes are likely to overheat and fade and quit working.

The brakes win over the engine. Now stopping from high speed, I can't say as to the overheating issue. I would hope they're engineered to be able to stop a car from max speed, under full throttle, before failing, though. Airplane brakes and wheels are required to do this -- maximum landing speed, like 220 MPH + full load weight and under full throttle, they have to be able to stop the plane and not burst into flames for 5 minutes or something.

It's a fascinating test to watch, and incredibly impressive.

[Shrike]

They used to have hydraulic breaking as well. It's quite possible they discontinued that, though.
Sorry, that's what I meant. Same hydraulics for brakes, steering and suspension. Nowadays only on the expensive models.
Doesn't power steering progressively disengage at higher speeds anyway, or is that just an option on slightly better equipped cars? It's desirable in any event.

Well, disengage. The amount of assistance gets less, because you need less at higher speeds (you only make small adjustments).

[Shrike]

Three days earlier, another person had been driving the same loaner car and had the pedal get stuck on the floor mat.

Sorry about this story. But a floor mat getting stuck is not the fault of electronics, is it?

Doesn't turning the key off also lock the steering column?

Yep.

[GreyICE]

First, for that to happen, his engine has to kick his brakes' arse. Since it ain't a GTR, it ain't happening (and maybe not even there). Even if the cruise control gets stuck, and even braking doesn't cancel it, your brakes can always overpower your engine.

That's the last and final word. No ifs, ands, or buts.

That being said, it looks like that's what he had to do. A cruise control that malfunctions that badly is a very serious design flaw. Overpowering your own engine with your own brakes is a TERRIBLE idea, even if its possible. Many people in the general public are absolutely unaware that you can shift to neutral or turn off the engine while the car is in motion and panic situations are not where they're going to learn. Moreover, assuming the car refused to stop going forward unless he shifted gears (which, once again, most people don't know you can do), braking to a halt doesn't really solve the problem. Moreover, that much braking is DANGEROUS. Even with anti-lock, you have almost no ability to steer, and no ability to dodge anything.

I don't think he's a liar, the call sounds legit, and Ford is even calling it a 'one-of' flaw.

I think he's telling the truth.

[a_unique_person]

First, for that to happen, his engine has to kick his brakes' arse. Since it ain't a GTR, it ain't happening (and maybe not even there). Even if the cruise control gets stuck, and even braking doesn't cancel it, your brakes can always overpower your engine.
No, got him down to 80k, he says. Then they faded.

[GreyICE]

No, got him down to 80k, he says. Then they faded.

Huh. Possible only if the pads were worn to crap, or the brake line had a failure.

I haven't had to deal with brake pads in a while (nor do I have cruise control), so I honestly don't know how much effect worn brake pads would have. The fading is consistent with low brake fluid levels. Then again, many people drive with low brake fluid, so it could be a combination of driver incompetence and massive malfunction.

[Beerina]

I can't conceive of any remotely healthy brake system failing like that unless it's as GreyICE described, or possibly a design flaw. The one thing it wouldn't be is overheating due to full throttle.

Just guessing, but I'm guessing the engine under full throttle would not even double the energy absorbed stopping. Why? You can stop faster than you can start. In any case, it's in the same ballpark as 2x a normal braking, which should be way, way under brake failure from overheating.


It's also a good argument that that ancient Audi (was it?) famous case that was on 60 Minutes wasn't true, as described. They also claimed a malfunction with the engine computer that rocketed the car ahead through a garage door and killed someone, pinning them against the wall. They produced a brake pedal that was supposedly bent from the force of her jamming her foot down. IIRC, the car company lost, even though this was engineering idiocy for much the same reason.

Note the lawyers didn't claim a delayed reaction lead to her stomping the brake pedal too late, but rather that the engine was so out of control from the buggy engine computer it overpowered, ludicrously, the brakes.

The car company maintained she stomped the gas by mistake. In any case, this case is mostly what's driven all the oddball shift levers and requirements to have the foot on the brake and in park to start the car, and the foot on the brake to shift out of park and blah blah blah.

I presume people have done scientific studies to show a decrease in the number of sudden overplowings of byfrontstanders. :rolleyes:

[screensnot]

Sorry about this story. But a floor mat getting stuck is not the fault of electronics, is it?Obviously not. But many people weren't buying the stuck floor mat explanation. There were claims from Toyota/Lexus owners that they had unexpected acceleration when no floor mats were in the car.

Yep.Any car built in the US (don't know about other countries), within the last 50 years or so, has a mandatory safety feature that keeps the steering wheel from locking, if you turn the key off in an emergency.

For example, an automatic transmission has an interlock that won't let the key turn far enough to lock the steering, unless the car is in park. For manual trans, you also have to push a button, in order to turn the key far enough to lock the steering.

[DGM]

Huh. Possible only if the pads were worn to crap, or the brake line had a failure.

I haven't had to deal with brake pads in a while (nor do I have cruise control), so I honestly don't know how much effect worn brake pads would have. The fading is consistent with low brake fluid levels. Then again, many people drive with low brake fluid, so it could be a combination of driver incompetence and massive malfunction.
If he road the brakes long enough the failure would have nothing to do with fluid level or pad condition. The problem would be the brake fluid could boil. You really have to beat on the brakes to do it but, it does happen.

[lionking]

And, of course, the brakes stopped the car in the end.

[DogB]

IIRC, the car company lost, even though this was engineering idiocy for much the same reason.

Litigious owners assisted by one of 60 minutes finest hours.

In 1986 "60 Minutes" turned its attack journalism on the Audi 5000, despite the fact Audi had one of the best safety records on the road. "Sudden acceleration" was the hobgoblin now, and Olson quipped that the segment presented Audis as though they had been possessed: backing into garages, darting into swimming pools, plowing into bank teller lines, doing everything but flying on a broomstick –even as drivers were standing on the brake. Audi lawyers claimed that the "expert" in the segment, William Rosenbluth, had drilled a hole in the car's transmission, and attached a hose leading to tank of compressed air or fluid. Even though the tank and attached hose were sitting on the front passenger seat of the Audi, those intrepid investigative reporters at 60 Minutes managed to keep any view of the tank off camera and out of the awareness of viewers.

Linky (http://www.aim.org/media-monitor/the-cbs-cold-case-files/)

Oh and it just went on and on (http://www.manhattan-institute.org/html/cjm_18.htm). I believe some cases were still outstanding in 1997. It wouldn’t surprise me at all if there was still somebody out there trying to screw another few million out of Audi.

[Shrike]

Obviously not. But many people weren't buying the stuck floor mat explanation. There were claims from Toyota/Lexus owners that they had unexpected acceleration when no floor mats were in the car.

Only claims so far IIRC.

Any car built in the US (don't know about other countries), within the last 50 years or so, has a mandatory safety feature that keeps the steering wheel from locking, if you turn the key off in an emergency.

For example, an automatic transmission has an interlock that won't let the key turn far enough to lock the steering, unless the car is in park. For manual trans, you also have to push a button, in order to turn the key far enough to lock the steering.
That's not the case everywhere. Automatics have that, but not (all) manuals.

[screensnot]

Only claims so far IIRC.Yes, which is exactly why I used the word 'claims'.

That's not the case everywhere. Automatics have that, but not (all) manuals.I don't know about everywhere, which is why said in the US. Which country doesn't have that safety requirement for manuals?

[WildCat]

You can still steer and brake without having the engine on; it just takes more effort (a lot more, in the case of brakes, but they still work). And most cars don't have stability control anyway. So long as you kill the ignition but don't turn the key so far that the steering lock can engage, you should be fine.
The steering wheel lock doesn't engage unless you put the transmission in "park".

[LTC8K6]

If the brakes had faded to to the point of not working at all, they probably wouldn't have stopped the vehicle. It would take a long time for the fluid and pads/rotors to cool down to the point where the brakes would work well again.

Since the brakes did stop the vehicle, I can only conclude that they never faded very much...

[LTC8K6]

Keep in mind that Toyota's fix does indeed involve adding brake/throttle conflict recognition to the DBW system's programming.

Something that is already a part of most modern DBW systems.

[ktesibios]

Obviously not. But many people weren't buying the stuck floor mat explanation. There were claims from Toyota/Lexus owners that they had unexpected acceleration when no floor mats were in the car.

Floor mats have been a problem in the past. In the late '90s Honda had to recall a number of Civics because the floor mats could shift out of position and jam the gas pedal.

Any car built in the US (don't know about other countries), within the last 50 years or so, has a mandatory safety feature that keeps the steering wheel from locking, if you turn the key off in an emergency.

For example, an automatic transmission has an interlock that won't let the key turn far enough to lock the steering, unless the car is in park. For manual trans, you also have to push a button, in order to turn the key far enough to lock the steering.

I didn't know that was mandatory, but my '97 Civic has just such an interlock. To turn the key to the lock position the shift lever has to be in the PARK position and the key has to be pushed in and then turned.

[screensnot]

I didn't know that was mandatory, but my '97 Civic has just such an interlock. To turn the key to the lock position the shift lever has to be in the PARK position and the key has to be pushed in and then turned.

I looked hard, and can't find anything to confirm that it is mandatory. So, I guess the most I can say, is that every vehicle that I am familiar with had the safety feature.

I would also like to say, to anyone reading this, that if you aren't sure about your vehicle, you should check it out. It could be the difference between living and dying in an emergency.

[lionking]

Had to re-open this one.

http://www.theage.com.au/national/no-fault-in-cruisecontrol-terror-car-20100107-lwdd.html?autostart=1


A police investigation into Melbourne's runaway cruise control vehicle is finished, but it hasn't provided the answers the terrified driver was looking for.
Chase Weir, 22, was given back his 2002 Ford Explorer this week after it was impounded at the end of his white-knuckle ride on December 15 down the EastLink freeway with the cruise control apparently locked in.
Police say mechanical experts in the force's major collision unit examined the car for several weeks but determined there was no need to investigate further.
One of the lead investigators in the incident, Detective Senior Constable Paul Baggott, said he was limited in what he could publicly say, but confirmed the case was now considered closed.


My position originally was either driver stupidity or (more likely in my opinion) hoax. This is confirmation that the car wasn't faulty.

[a_unique_person]

The quote goes on


One of the lead investigators in the incident, Detective Senior Constable Paul Baggott, said he was limited in what he could publicly say, but confirmed the case was now considered closed.
"There's no element of criminality," he said today. "There was damage that was consistent with the events of the day."



A hoax would be rightly prosecuted. The event put people's lives at risk and must have cost a lot of time and money.

[lionking]

Sure. The coppers are saying "no evidence", they are not saying the driver's version is correct. They can't prosecute a hoax without evidence. But I think one plank of Chris Weir's story has been kicked away, that's all.

[a_unique_person]

Sure. The coppers are saying "no evidence", they are not saying the driver's version is correct. They can't prosecute a hoax without evidence. But I think one plank of Chris Weir's story has been kicked away, that's all.

I'm more inclined to think software glitch. I've worked with computers long enough to suspect one. No piece of software is every bug free. Some of the Airbus problems I'd guess are software also.

[Shrike]

I'm more inclined to think human glitch. I've worked with humans long enough to suspect one. No human is ever bug free. Some of the Airbus problems I'd guess are human also.

[jta]

Just to add to this, I had a brake failure in a Lexus a couple of years ago, I was going down a long mountainside road at the time, fortunately after the hairpin bends, when I touched the brakes, nothing, except a very very solid pedal. I literally had to stand on them to make any impression on my speed at all. This , of course, with no stuck throttle, but on a very steep incline. I survived, obviously. On investigation of the problem later I found the vacuum servo had snapped a bolt on a shaft that held the diaphragm. This is a fault that I had never come across in all my working life as a mechanic and garage owner. So, while I think this guy was lying, there is a niggling doubt that there just might be something that has slipped past all the design checks.

[politas]

According to reports.

He called Ford and the Police. They advised him to turn off the ignition, and put the car into neutral. The software over rode his ability to do so. He could not put it into neutral, nor turn off the ignition. He was talking to them and doing what they said. I can't believe it was something to dodge a fine, he nearly lost his life.

It's amazing how people can panic and get themselves into thinking that being caught lying is worse than anything else that could happen to them.

[a_unique_person]

I'm more inclined to think human glitch. I've worked with humans long enough to suspect one. No human is ever bug free. Some of the Airbus problems I'd guess are human also.

Except that he obviously knows how to put his foot on the brake. With cruise control, that's all it should take.

[CORed]

Doesn't turning the key off also lock the steering column?

Every car I've ever owned with a steering column lock had a key position that turns off the engine without locking the steering. On many, if not all, you have to push a button or lever to get the key to go to the steering lock position. My current vehicle, a 2005 Jeep Liberty with automatic, will not allow me to lock the steering unless the shifter is in Park. I had a stuck throttle once, not wide open but maybe half open (frayed cable) and managed it by shutting of the ignition.

ETA: The stuck throttle was not on the Jeep. It was on a 1973 IH Scout II. It had a stranded wire cable for a throttle linkage. The cable frayed, and got stuck in the guide tube. Bad design, IMO.

[CORed]

Obviously not. But many people weren't buying the stuck floor mat explanation. There were claims from Toyota/Lexus owners that they had unexpected acceleration when no floor mats were in the car.

Any car built in the US (don't know about other countries), within the last 50 years or so, has a mandatory safety feature that keeps the steering wheel from locking, if you turn the key off in an emergency.

For example, an automatic transmission has an interlock that won't let the key turn far enough to lock the steering, unless the car is in park. For manual trans, you also have to push a button, in order to turn the key far enough to lock the steering.

Well, steering locks didn't become common on American made cars until the late '60's. Prior to that, most had ignition locks mounted on the dashboard. Most of these were ridiculously easy to hot-wire.

[Ziggurat]

Many people in the general public are absolutely unaware that you can shift to neutral or turn off the engine while the car is in motion

In fact, on my car (an automatic), you can shift from drive to neutral without even squeezing the button. In an emergency situation, all you need to do is slam it forward. And by NOT pressing the button, you guarantee that you won't accidentally overshoot to reverse or park. I haven't tried this out on other cars, but I suspect it's probably common now for automatics.

[Ziggurat]

Well, steering locks didn't become common on American made cars until the late '60's. Prior to that, most had ignition locks mounted on the dashboard. Most of these were ridiculously easy to hot-wire.

My parents used to have a '62 Chevy Impala. It got stolen once but eventually recovered. The thief had installed a button under the dashboard to automate the process of hotwiring it, and it never got removed. On really cold days, if the car had problems starting, sometimes it would help to turn the key AND press the hotwire button at the same time.

[LTC8K6]

http://www.caranddriver.com/features/09q4/how_to_deal_with_unintended_acceleration-tech_dept

Car and Driver reprises it's full throttle braking tests.

[politas]

In fact, on my car (an automatic), you can shift from drive to neutral without even squeezing the button. In an emergency situation, all you need to do is slam it forward. And by NOT pressing the button, you guarantee that you won't accidentally overshoot to reverse or park. I haven't tried this out on other cars, but I suspect it's probably common now for automatics.

Automatic gearboxes shouldn't engage park or reverse while the car is moving forward, anyway. The Mythbusters tried it a few years back. Changed to reverse and to park while travelling at 50mph. It had the exact same effect as just putting it in neutral. That whole "and then, I put it in "R" for "race" and the engine blew up!" is just a funny story.

[wafonso]

Except that he obviously knows how to put his foot on the brake. With cruise control, that's all it should take.

True, but I would put a very strong emphasis on "should". There have been confirmed reports of cruise control failing to disengage in cars of different makers, sometimes with very bad results.

[Sir Robin Goodfellow]

An automatic transmission has a fail-safe built into the valve body that will not allow reverse to engage at speed. When "rocking" a stuck vehicle, you can however engage reverse when the vehicle is still moving forward under its own momentum. This is a bad idea, as it puts stress on the sprags and output shaft.

Park is a purely mechanical system, as opposed to the other selections which are hydraulic. There is a rod that pushes a spring-loaded pawl into a lugged gear at the rear of the transmission. When you attempt to select "park" at speed, the pawl just ratchets across the lugs, wearing down the pawl. Once you have slowed to a crawl, the pawl will eventually lock into place and stop the vehicle. Do not try to shift into park until the vehicle is completely stationary, as the sudden force on the lugs can break the rear annulus gear.

[Ziggurat]

rear annulus

<beavis>He he. You said "rear annulus". He he.</beavis>

:duck:

[rwguinn]

An automatic transmission has a fail-safe built into the valve body that will not allow reverse to engage at speed. When "rocking" a stuck vehicle, you can however engage reverse when the vehicle is still moving forward under its own momentum. This is a bad idea, as it puts stress on the sprags and output shaft.

Park is a purely mechanical system, as opposed to the other selections which are hydraulic. There is a rod that pushes a spring-loaded pawl into a lugged gear at the rear of the transmission. When you attempt to select "park" at speed, the pawl just ratchets across the lugs, wearing down the pawl. Once you have slowed to a crawl, the pawl will eventually lock into place and stop the vehicle. Do not try to shift into park until the vehicle is completely stationary, as the sudden force on the lugs can break the rear annulus gear.
If I am in an emergency situation with a jammed throttle, the structural integrity of the rear annulus gear is not going to enter into my consideration.
Nor will I be too upset at watching pistons exit through the hood...

[Damien Evans]

In fact, on my car (an automatic), you can shift from drive to neutral without even squeezing the button. In an emergency situation, all you need to do is slam it forward. And by NOT pressing the button, you guarantee that you won't accidentally overshoot to reverse or park. I haven't tried this out on other cars, but I suspect it's probably common now for automatics.

It's the same on my parents, and every other auto I've been in for at least 15 years (and given my dad used to work for Ford and now works for Kia, that's rather a large number)

[Sir Robin Goodfellow]

If I am in an emergency situation with a jammed throttle, the structural integrity of the rear annulus gear is not going to enter into my consideration.
Nor will I be too upset at watching pistons exit through the hood...


Agreed, but park will not stop your vehicle at highway speed. It's more like at about ten KMPH when careless drivers attempt to engage park and find themselves $2000 poorer.

A better idea in an hypothetical runaway situation would be to manually downshift to low, to take advantage of engine braking when your applying the park brake and standing on the service brakes slow the vehicle enough to get the transmission to grab first gear.

[casebro]

A conceivable scenario is that the driver is too timid with the brakes.

While a full panic application would stop a car with a racing engine, applying a small amount of braking would allow the car to increase speed while heating up the brakes. Soon the driver would have to stop a faster car with less braking capacity.

I doubt that modern driving classes teach students to 'pump' their brakes. 40 years ago we learned to push the pedal, then ease off and let the brakes cool. It was necessary with drum style front brakes, less so with discs due to better cooling. Anyway, discs can overheat. If a driver only applies enough pressure to prevent further acceleration, then later the car still has as much energy (as momentum), and hot brakes too.

I only ever faded my brakes one time, drum brakes and a long hill. 18 years old then. Learned to pump them that day. Hate anti-lock systems. When I pump while they let off, trouble ensues. Better for an experienced driver to be in charge than a computer 'proxie'.

[Sir Robin Goodfellow]

Don't pump anti-lock brakes. Just step on them. The idea is that you can still steer while braking.

Modern driving lessons have not caught up with technology. Some instructors still tell you to hold the wheel at "ten and two", but that's no longer best, as airbags have made that advice obsolete. A "nine and three" grip will lessen the chance of injury should the airbag deploy. Some driving manuals do not even take into account power-assisted steering and braking systems, though they've been commonplace for thirty years.

[LTC8K6]

You must not attempt to use the brakes to control the speed of a runaway vehicle. The brakes will overheat and fade to uselessness if you attempt this.

You must get on the brakes hard the first time and stay on them hard to stop the vehicle. Any attempt to merely control the speed will not end well.

If your vehicle has brake assist, the computer should detect your attempt at a panic stop and apply the maximum braking force possible, even if you aren't doing so with your feet. Brake assist relieves you of the need to press extra hard on the brakes in trying to stop your car quickly.