Toyota Recall 7

[keller36]

Hello. I am new to the forum and had a rather extensive question. I am wondering what system is causing the sudden acceleration problems in Toyota vehicles as well as the specific part in that system, if any specific part is respoinsible. I was also wondering, depending on the system involved in the problem, whether the problem is electrical, mechanical, or a problem in the vehicle's software. Thank you for any responses.

 

[BrianPetersen]

Oh boy ...

If we or anyone knew the answer to that question, it would solve an interminable amount of arguing.

The short answer is that no one knows.

The slightly longer answer is that floor mats were an issue in some cases, and a mechanically "sticking" accelerator pedal may have been an issue in some other cases, but there are still an ample number of situations out there for which "sudden unintended acceleration" reports exist, but floor mats weren't an issue and the vehicles weren't equipped with the particular accelerator pedal sensor under recall.

A certain Professor Gilbert claimed to have found a situation in which the pedal sensor could be bypassed to cause a situation that looks to the car's computer like full-throttle acceleration, but Toyota hired an engineering firm which has pretty much showed that the circumstances created by the professor were all but impossible to occur accidentally in the real world. Keep in mind that you can deliberately and intentionally circumvent ANYthing if you have the right tools and experience.

That there are some sub-optimal situations in some or all of the involved vehicles, is known. Toyota has not been using an accelerator/brake interlock circuit that would override accelerator input if someone stepped on the brake. But, motor vehicle safety standards require no such system, so this is not a "non-compliance". The European manufacturers have been doing this because one of them has already had their round of "sudden acceleration" issues many years ago.

The push-button keyless engine start is a problem, because it's not readily apparent how to switch the engine off while moving.

But, there is a big elephant in the room that, for some reason, nobody wants to mention: operator error!

People stepping on the wrong pedal is every bit as much of an issue now, as it was in the late 1980's when this was a big issue the last time.

And, every single one of these "sudden acceleration" situations, even if they actually did happen and weren't the figment of someone's overactive imagination, could be stopped in its tracks by shifting the transmission to neutral.

My car has an instant engine disengagement device that is totally mechanical/hydraulic and not reliant on any software. It is called a "clutch pedal". Sadly, not too many Americans seem to know how to use one.

 

[evelrod]

Newest occurrence of the Toyota Syndrome lately was on the I8 in San Diego Sunday. Gentleman went to Toyota dealer and complained but was told his Prius did not qualify. Next day on the freeway the car accelerated and could not be turned off or put in neutral, apparently. He called 911 and a Highway Patrol unit found him and while driving along side gave instructions via the loudspeaker. Full braking brought the speed from 94 to 55 and, it gets a bit vague here, the CHP was able to get the car stopped...Article in the North County Times/Californian on Monday. The interview I saw later on the local news was pretty much the same story but the gentleman was NOT happy about the way he was treated by the local Toyota dealer.

I've given up on trying to figure out what is going on. Obviously I have some ideas that others on the forum share. I'm content, at this point, to see how politics saves the "good name" of Toyoda.

Rod

 

[TrackRat]

Just so the OP knows, Toyota's "issues" are several or I should say that there are several issues with Toyota vehicles and the drivers operating them.

For the record a number of accidents have been reported by drivers pushing the floor mat under the accelerator pedal. This resulted in a terrible accident in CA a few weeks back where four people were killed. Kicking the floor mat under the accelerator pedal is an operator error not a vehicle defect. People do this in many different makes of autos.

To help prevent future accidents from drivers kicking the floor mat under the accelerator, Toyota is retro-fitting their cars with a failsafe engine management system so that when a driver pushes on both the brake pedal and accelerator for more than a few seconds, the throttle is automatically returned to idle electronically, regardless of where the accelerator pedal is in it's operating range. Many car makers have had this failsafe system since cars began using Drive-By-Wire, (DBW), instead of a mechanical throttle cable.

Toyota has another situation where a limited number of vehicles have a sticky accelerator pedal. This is a defect and Toyota is repairing all cars with this problem. The problem is a mechanical one in the accelerator pedal assembly. This problem has occured in other makes also over the years.

The third issue is with the Toyota Prius hybrid vehicles. Some drivers report abnormal braking with these vehicles which use a regenerative electrical system based off of the brake system. It's complex and may or may not have a defect in it. It does operate differently than conventional hydraulic brakes and this may be what drivers are sensing? We will know more as the investigations continue.

Because most drivers have limited technical understanding of the complex computer based systems in an auto, many have proclaimed that the "black boxes" are possessed and that they take over control of the vehicle and cause unintended acceleration. This has never been substantiated and is typical speculation and lack of knowledge at work. Toyota has agreed to open the "black boxes" for all to see and has agreed to as many independent investigators as the Feds feel is necessary to confirm the only problem is with the sticky mechanical accelerator pedal on a limited number of vehicles.

Naturally if a driver crashes their car they want to blame someone else and the siren chasers are out in full force. Like the Audi unintended acceleration of the 80's I expect that when the dust settles Toyota will pay out Billions in damages for driver errors and that no one will ever be able to prove unintended acceleration happened, because it probably didn't.

Sticking throttle pedals are dangerous but the brakes will stop any modern vehicle if properly applied even with the throttle wide-open. Numerous auto industry experts have tested and conformed this on the Toyota models, so if the throttle sticks, a driver most certainly can stop the vehicle by properly applying the brakes.

The latest episode in the Toyota hysteria is a Prius owner who claims today that he Prius took off on it's own and was doing 94 mph on the highway in CA. He claims the brakes would only slow the car to 55 mph and that placing the shifter in neutral did not disengage the power to the wheels. A police officer got his vehicle in front of the Prius and had no difficulty slowing the Prius while telling the driver over a loud speaker to shut the engine off - which he eventually did. You would have thought the driver might have considered that before he called 911...

 

[dicer]

As a personal opinion, I feel the problem has always been electronics/programming.

I am truely amazed that the electronics systems in any device work as good as they do. But we all know about the occasional lock up of our PC's that we use daily if for nothing else comming online to sites like this.
With the ever increasing densitys of discreet electronic components, where insulation separation is in the nano world of a molecule or so, I'm really surprized there are not more problems occuring. Electronics has its place, but I think the manufacturing world is going crazy with it.
High heat, high vibration, high moisture, and dirty places are just not a good place for electronics especially when lives are at stake. I remember reading someplace on this site about the current Toyota problems and how some here said they wouldn't design a machine without a big red emergency stop button, I fully agree, problems are if Toyota did that they would most likely still have it go through a computer to shut things down. The right way to do it is cut all power to everything, but then theres another problem, the day is comming where every system in the vehicle will be electrical - electronic, and if you shut off all the power then, you would have nothing, no steering no braking no nothin, ya couldn't even open the doors or windows. Can't we see how crazy this is getting?
Things need to change, and go back to the past when reliable systems existed.

 

[izzmus]

I, for one, would like to know why a button is better than sticking a key into a lock cylinder and turning it.

Some things are expected. The pedal on the far right is the accelerator, the pedal next to that is the brake, and for some people, the pedal next to that is the clutch. Directional control is via a somewhat vertical wheel that is rotated clockwise to go right, counterclockwise to go right. Shift patterns are essentially standardized, with Reverse for manual shift being the only odd man out. The control stalk at the left hand operates the turn signals.

Why does something else similarly important (especially in an emergency) need to be different for difference's sake?

I'm not specifically slamming Toyota, here, as there are certainly other makes doing strange things to controls that should be free of question. (Jaguar, I think, has a rotary knob shift lever that disappears into the console when the vehicle is off, for example)

I can understand the push for wanting to do away with cables and linkages and hydraulic connections. On the other hand, the driver's air bag could be simpler if the steering wheel didn't have to rotate - it could use a compressed-gas canister instead of an explosive.

 

[TrackRat]

Fly-By-Wire has worked fine for decades and that's what auto electronic management is based on. I don't think we should jumpt to conclusions that electronics or anything else is the issue until we have documentation of same. The media and others have already speculated far too much IMO. This leads to false conclusions that make lawyers very wealthy.

 

[DanEE]

The Prius already has the brake override function. I've tested it several times in my 2006 model to get familiarized with how it works.

With full throttle (accelerator to the floor), the initial braking is just resistance against the engine as in any car, but as brake force is increased (doesn't take that much pedal force) it transitions into a mode where the throttle starts backing off on the engine to near zero...

As you roll to a complete stop (accelerator still on the floor) engine speed will increase slightly, just enough to know it still pulling against the brakes.. but the engine is no contest against the brakes nor is it trying hard while you still have your foot on the brakes.

Take your foot off the brakes and it goes back to full throttle, since the accelerator is still on the floor..

Now the question... how many people are going to get confused with brake over-ride???

Perhaps the safest car is the solution Jay Leno jokes about.. when you press the accelerator, nothing happens.. the car doesn't move.

 

[MastDesgin]

Personally I'm a huge fan of throttle cables, I'm also a enthusiast driver so I like full control over my car. All the cars I drive have a throttle cable, a key, and a clutch. I put a lot of faith in computers, I put my financial future in the hands of computers as far as work goes. But I will never trust a computer with my life (except airplanes). I go with Murphy on this one, if there's something there to fail it will. I have 3 fail safes in case of a "acceleration" problem in my cars Turn off key, Pull out of gear, Push on brakes (merc's have computer controlled brakes!!!!!).

When it comes to the Toyota issue, a simple transistor would of saved lives. all throttle signals go through this transistor when the brake is pushed it puts power to the transistor turning off the gas! Leave throttle cables on there Performance cars for power braking and Heel Toe Shifting...

 

[TrackRat]

FWIW, DBW cars can also be heel-and-toed as it takes a specified time for the failsafe system to cut in - usually 4-6 seconds with both the brakes and accelerator pushed.

I highly doubt the black boxes are the issue but we'll see what the investigations show. In my experience about 95.367894291326 % of U.S. drivers should not be operating a motorized vehicle because they lack the proper skills, training and knowledge which results in accidents, injuries and fatalities. Maybe all car makers should be forced to place a large label on the windshield in front of the driver stating: THE BRAKE PEDAL IS NOT ON THE RIGHT !

<LOL>

 

[LionelHutz]

Funny thing, I asked my co-worker with a new Toyota Corrolla if he's had problems with catching the gas pedal. He responds that he's stepped on both pedals 2 or 3 times when he had boots on and the car tried to take off. But then, he's sharp enough that he caught his error quickly. He did say he came within a foot or less of hitting his BBQ one time.

So, how many people would panic and just step on both pedals harder exaberating the problem?

I read one report with a table holding some of the complaints. There was a lot of complaints that basically read "as I turned into a parking spot the car took off" reported. Sounds to me they should read "as I turned into a parking spot and tried to brake I accidentally stepped on both pedals and cause the car to take off".

I've done it in my car a few times(a GM model). In those cases, I found the extra throttle would over ride the extra braking as I stepped further on the pedals and the car would not slow down. It's drive by wire as well, but I'm not losing any sleep over it acting up.

 

[JSteve2]

The I8 guy did not shift the car into Neutral, and the car did stop when he hit the power button. I watched the interview very carefully for this. He claimed he did not do either of those at speed because he didn't feel it was safe at the time (I'm not judging him, either - I wasn't in his situation). You could kind of tell by the question he hadn't really thought of the Neutral issue anyway.

Most of the weird stuff is no doubt software related. There are any number of issues that can cause this - integrator windups, data value overflows, an A/D error from the accelerator signal, etc. all of which would be somewhat surprising in the abstract. However, since there is clearly an issue here, I expect that something like one of those issues will eventually be found.

 

[dgallup]

I don't care how FUBAR the electronics get, if the driver stands on the brakes the car will stop. End of story. Any accident, however tragic, is the fault of the driver. Never the less, I'm sure there will be a bunch of ambulance chasers get rich before this is over. People are coming out of the wood work with one crazy story after another. It's a media feeding frenzy. For the paranoid, how much of this is being stirred up by the government ownership of GM?

 

[ewh]

Is the OP a Toyota employee? ;-)

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[ivymike]

I don't care how FUBAR the electronics get, if the driver stands on the brakes the car will stop. End of story.

That's a bold statement, and seems to be unsupported by facts. I have a regular-size female friend who isn't strong enough to screech the tires by stomping the brakes in her altima - we tried it repeatedly one day - she figured it was because they were "antilock" until I demonstrated what would happen if I stomped on them. You're telling me that she could brake hard enough to rapidly overcome full engine power, starting at speed? I doubt it. Then there was the case of the CHP officer who crashed... you're saying that he just hadn't thought to try the brakes?

 

[GregLocock]

Admittedly if you won't push hard enough on the brake then there is a problem.

But these guys didn't really find much of an issue

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

"Certainly the most natural reaction to a stuck-throttle emergency is to stomp on the brake pedal, possibly with both feet. And despite dramatic horsepower increases since C/D’s 1987 unintended-acceleration test of an Audi 5000, brakes by and large can still overpower and rein in an engine roaring under full throttle. With the Camry’s throttle pinned while going 70 mph, the brakes easily overcame all 268 horsepower straining against them and stopped the car in 190 feet—that’s a foot shorter than the performance of a Ford Taurus without any gas-pedal problems and just 16 feet longer than with the Camry’s throttle closed. "

It doesn't mention what pedal pressure they used.



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[MastDesgin]

I don't know if I'm more surprised the Camry stopped or that Camry's come with almost 300 HP... I wonder how the transmission handles it. Would it keep gearing down every chance it got or would it stay in the high gear?

 

[BrianPetersen]

If the system is seeing a full-throttle input (regardless of reason), and there's no accelerator/brake interlock (which there hasn't been, on that car), it'll keep downshifting.

The oversized engines available in North America may be part of the issue here. A Toyota Yaris 1.3 or Toyota Aygo 1.0, which are more typical Toyotas sold in Europe, doesn't do ANYthing "suddenly".

 

[MastDesgin]

I think at the point it kept downshifting there would be no way to stop it... you might pull it down to the next gear change then it would push even harder against the brakes and at that point brake fade would be so bad you couldn't think of stopping... now if you locked the brakes that might be a different story doesn't give the brakes a chance to fade... but then ABS comes in and might mess ya up there...

 

[BrianPetersen]

One of the major auto enthusiast magazines recently demonstrated that a Camry will stop given hard brake application, even at full throttle. The problem arises if the driver doesn't press the brakes *hard* and hold them all the way until the car is stopped.

And ... you can always shift to neutral.