Well, the whole reason that throttle-by-wire was adopted was in response to government mandates for higher fuel economy.

What better way to curb the lead foot and conserve fuel than taking control of the throttle?

Taking control of the throttle, particularly during cruise phase optimizes performance based on road condition demand.

Going back to mechanical linkages would surely fix the software bugs, but I am not convinced that Mr. Flint has considered the ramifications of downgrading corporate fleet average economy dictated by government CAFE standards.

A better question to ask would be if the government would be willing to relax CAFE standards to accommodate safety?

The answer is clearly no and additionally, US Senators are basking in the limelight of grilling Toyota so that they can appear to be the champions of the people. "Never waste a crises", I believe were the words uttered by our leaders.

Your arguments are a little scattered, but let's stick to the point. The word "whole" was a little too general on my part. So, it's maybe not the whole reason, but for passenger cars the big driver for developing the technology was improving gas mileage and emissions. Early adaptations of ETC (Electronic Throttle Control) were implemented primarily for the ability to gain control of the intake air supply (something not possible for Engine Management Controllers previous to ETC).

The early versions were not as well received because they did (in a small way) annoy drivers by overriding some driver inputs. This led to refinements in the technology as we have today, which is pretty much invisible to the driver.

As the technology advanced, stability control, shifting, and other benefits were taken advantage of and further developed. Those systems worked hand in hand..

I still contend the kick start was a means to improve performance of the vehicle and meet tightening fuel economy and emission standards. Your argument was mostly that present advantages were the drivers and many of these functions followed the development of ETC.

That doesn't preclude leveraging other advantages along the way of development. That's a given.

Your arguments are a little scattered, but let's stick to the point.

Sorry you had a hard time following along. The point of my post is that your statement "Well, the whole reason that throttle-by-wire was adopted was in response to government mandates for higher fuel economy." was, and is, flat wrong.

The reason I responded to your post was because there is already plenty of incorrect info circulating (because of the Toyota debacle) and adding more drivel does not help anyone.

The Wikipedia article on ETC is essentially correct:

• ETC facilitates the integration of features such as cruise control, traction control, stability control, and precrash systems and others that require torque management, since the throttle can be moved irrespective of the position of the driver's accelerator pedal. ETC provides only a very limited benefit in areas such as air-fuel ratio control, exhaust emissions and fuel consumption reduction, working in concert with other technologies such as gasoline direct injection.

You can read through a couple editions of the Bosch Automotive Handbook, and see that your hypothesis is wrong. The 1993 edition (the third) was from the relatively early days of EMS (the Bosch nomenclature for ETC). In the introductory paragraph about the system, they mention only "performing such tasks as torque reduction for electronic traction control (ASR)". They go on in a later paragraph to say that "EMS can perform various functions to enhance driving safety, convenience and engine management. After several paragraphs describing the uses of EMS in safety, convenience and comfort, they make one final statement re engine management: "Development is being carried out to adapt EMS to effect other engine related improvements (e.g., for improved fuel consumption.)"

So clearly, as I said, it was safety, convience, and comfort that were the drivers. In 1993 uses for the very slight effects on emissions and even slighter effects on fuel economy (beyond those that can be met by conventional cruise control) were still in the future.

So you have the development cycle backwards.

Maybe I do have it backwards, but I am not so sure...

ETC Development

Also, read the first sentence of this article:

ETC Development

You can just as easily find contradicting sources, too, so it is not so "clear".

However, just as saying that the 'whole reason' is technically incorrect, so is saying that 'flat out wrong' is incorrect. They are both too broad a statement.

As for traction control, early and even recent versions of traction and stability control relied on applying braking to individual wheels. This was done on cars without ETC. Porsche 911s are a good example of this. Traction and stability control was not dependent on ETC, although, the two systems are merging as the systems mature.

I kind of see the argument as being a little petty. I stated that the sole reason was economy, you stated that economy had nothing to do with it (i.e., flat out wrong). I contended that the 'whole reason' was a poor choice of words on my part. The truth seems to lie somewhere in the middle and in 100 years from now it won't even matter. :-)

I kind of see the argument as being a little petty.

I'm glad you were able to admit that. My own arguments, however, are profound, insightful, and reality-based. No... seriously, I agree that the argument on both sides could be considered petty.

My reaction to your original post has more to do with politics and tone than specifics, perhaps. ABS, ETC, traction control, stability control, and rollover control were all developed outside of government control, and were offered first on luxury and luxury-sports cars (and re rollover control, a luxury crossover SUV, the Volvo XC90). Very large numbers of people gladly paid $1000 or more extra for ABS in the early days, and ABS soon became a high profit item, with development costs having quickly been spread out over a large number of vehicles. Only after stability control has shown itself to be cheap to implement has the legal requirement to implement it on all US cars in 2012 come about. That requirement is no more onerous than the existing CAFE standards have been, which have been both easy to meet and easy to game: The German companies just pay the fines, GM hypes flex fuel (which makes a 15 mpg SUV appear to be a 45 mpg vehicle). Simple.

So although one can theorize that more efficient cars will be less safe, and that therefore, the CAFE standards should be relaxed, in practice is is hard to make that case. When fuel economy peaked in the mid eighties, deaths did not skyrocket. Since the fleet fuel efficiency peak in the 80's, the ton-mpg efficiency has improved dramatically, from 24 to 45. But death rates have not skyrocketed in that period.

A very easy way for manufactures to improve fleet fuel economy is to sell fewer SUVs and trucks. That would have a beneficial effect on safety, because is it primarily in collisions of two different masses of vehicle that the smaller car loses. Deaths caused by SUVs and trucks smashing into normal-sized cars have gone up in proportion to the numbers of heavy vehicles on the roads, and full-sized pickups have driver death rates that are about the same as the smallest cars (which are more dangerous than mid-sized cars). Get the pickups and truck based SUVs off the roads and death rates would drop, and the fleet fuel efficiency would improve.

Reverting to mid eighties ratios (25% trucks) from today's (50% trucks) would improve both safety and fuel efficiency but, sadly, leave rednecks and sociopaths with less ability to bond with their perceived brethren.

Your original post seems to suggest that car makers were forced into using ETC, because of oppressive government control over an area in which you may think -- I'm jumping conclusions in all this -- should be free-market based. But economy and emission control over the last couple of decades have been very nearly "no brainers" for manufactures selling into the US market. In 2004,when the Camry had ETC and the Accord did not, the Accord was significantly more fuel efficient, by about 8%, a very large margin in this market. (4 cyl. Camry: 24 mpg combined; 4 cyl. Accord 26 mpg combined). It's only at the lunatic fringe of the market (Prius, Insight, etc) where anything new and potentially challenging has been done -- and neither the Prius nor Insight were built to improve CAFE numbers.

How's that for a rambling rant? You're right... this is shaving points pretty fine, and in 100 hours (let alone 100 years) this will not matter much.

Part of my point was that government CAFE standards generated changes to vehicles to meet the tightening standards (both good and bad). Manufactures simply looked for the most economical pathway to get to market under those regulations.

I think the smog pump was a good example of the auto industry's reaction to standard changes.

ETC can be a win-win situation in this sense (unlike a smog pump). It can subtly control the throttle to maximize fuel consumption and it can improve shifting loads on the transmissions as well as open the door to more refined safety measures like stability control.

I have to agree, the electronic controls are there to boost economy and reduce pollution. I have driven electronic controlled cars for two decades and had little problem and certainly no out of control accelerations. I do find the electronics in the rest of the car a bit much, such as stability control and antilock brakes. I believe people should just learn how to drive their cars properly.

What I can not understand though is why can't the driver just shift the car into neutral or switch of the key off to cut power to the engine. Certainly the electronics do not over ride these. All cars I have looked at has the power for the fuel pump and the power to the injectors directly interrupted by the key switch.

"What I can not understand though is why can't the driver just shift the car into neutral or switch of the key off to cut power to the engine."

Doing that will be the last thing on almost everybody's mind when the situation unexpectedly happens. Never underestimate the power of adrenaline and how adversely it impacts cognitive thinking.

Also, bare in mind that the cases you hear about on the news are the spectacular ones. The rest are far less dramatic and some form of driver corrective action probably prevented the mishap from making the breaking news segment.

I for one, have had the sudden acceleration problem, in a 1974 f 100 pickup truck. due to previous owners wrenching, the acelerator cable was not properly attatched to the carb and block. When i stopped at a traffic light, the motor mount broke and the engine hopped forward a few inches, pulling on the accelerator cable, throwing thr throttle wide open. I stomped the brakes,hit park and killed the ignition key before i went 3 feet forward, back tires screaming. 302 v8 slightly hotrodded. People just can not drive these days. I could make millions, watching my mirror and hitting my brakes when i see people behind me driving and tailgating, looking the other way.

After being rear ended a few times, I got fed up with tailgaters in louisianna, and hung a 5 foot long 8 inch oak log off the back of my truck for a bumper, swinging back and forth, held on by some very strong arborist rope.

Had an 83 datsun diesel king cab, which basically came factory with no rear bumper. This was an improvement from factory, so i was allowed to use it without police complaint. and they wouldnt even drive behind my truck. I had fun with it, changing bumper stickers. "if you must tailgate me, please check seatbelt, insurance, and iq" "whats in your bumper, got oak,yet?" Glued a little tigger figure onto the log, "back off or bounce off" "if you dont get the picture, heres your sign" " ever see a car that hit a tree? want one" "fast and furious, meet slow and serious" I had fun with it. I am about to hang a log off my truck here, theyre getting on my nerves again. gotta check with state police first, but it should be ok.

anyway on the car problems now, i wonder how much the car owners current income and economic status increases the likelyhood of "sudden acceleration" or stopping problems. I bet broke toyota owners are now more likely to have problems than financially stable owners.

I had the same problem with a new Tempo. After we got the damaged fenders and grill fixed, my daughter had it happen to her. After we got the damaged fenders and grill fixed, we sold the !!!!!!! car. We never had the problem again. Neither one of us had any intention of shutting down the engine, since it also drives the steering pump, which at the time of the incidents, was the biggest concern, trying to avoid hitting what was in our path!

I have always found it strange that engineers, and politicians, have all of these facts, figures,and numbers to justify that what they did is better and good. Yet the common person just has his pocket book math and personal experience of what works and what doesn't to determine what is better or worse. If his pocket book math says its costing him more he will always believe it over what any engineer or politicians math may say otherwise.

Just the same is true of his personal experiences. If they tell him that something is worse he too will take that it is worse and have no regards for what the engineers or politicians say about him being wrong for thinking that something new is not better than what it was in the past. There are countless engineers and politicians saying that all this safety and mileage related crap is better and more cost effective. Yet there are countless millions of average people who have reasons based on personal real life experiences and costs saying that not all of these marvels of technical engineering are worth it but are rather in many ways are steps backward in performance, cost, comfort, and general usefulness.

Much of the improved fuel mileage hype is seen as crap by far too many. Some cars did get better but countless others where already there a long time ago that have been forgotten or excluded in the numbers for some very convenient reasons. Too many of us average nobodies still do have or did have vehicles, some of them built over 30 years ago, that ran consistently as high of numbers with lower overall operating costs than what the new so called high efficiency vehicles of the last decade plus get in real life driving conditions.

I for one do not need a certified dynometer readings to know my old pickup had far more power and better fuel mileage than what my newer one has now. Don't get me wrong, I like my big Red Ford but I hate its lack of power and the far lower fuel mileage it gets in comparison despite being much more aerodynamic and efficient or significantly heavier than what it replaced. My pocket book and my experiences tell me its true and I still have no reasons to believe otherwise. I also do not need certified tests to know that my friends car gets the same average mileage as a new Prius in the same realistic driving conditions despite being late 1980's Chrysler tech. He grins, brags about it, and shows it off every chance he gets!

I hear engineers saying that cars are getting bigger. WTF? Really? Where are the Cadillac cruise ships of yester year? Or the land yacht Lincolns of days past? What about the battle ship sized Buick's we rode around in as kids? Where did all of the old Pontiac yard barges and oil rig sized Oldsmobile's go? How about those Ford wagons that could seat four fat guys in the front seats alone? And those bus like conversion vans that could carry a little league team along with three adults comfortably? Where did the stadium sized Chrysler Imperials and Chevy Impalas disappear too as well? Non of these got bigger, only the small imports did. The larger half of the vehicular sizing and improvement equations seem to always get left out for some convenient reason.

The full size cars of today would not even be considered the middle size class that was in effect when these American monsters of metal represented the normal sized family vehicles of the day. The biggest SUV's out there are still far short of the conversion vans that where around 20 years ago. The real sad part is most of those old monsters got about the same real life fuel economy as the new stuff that replaced them does now, and some where even better.

Vehicles got bigger and mileage got better my ass. They only got bigger if you don't include the biggest that where already here decades before and those had key switches that actually shut things off. Plus the gas petal was attached the actual throttle mechanism and all the brakes had direct physical connections from the driver to the wheels. They didn't need to hide crappy engineering and poor design behind computers and code systems back then. Engineers and politicians be dammed, too many of us paid for the fuel back then and kept track of those numbers and to this day still do. Our pocket books and experiences just tell us something is not right with what we have now and no engineer or politicians facts, figures, or charts will make us believe otherwise.

Some things did greatly improve over the years, just not things that they feel the need to keep telling us are improvements.

Tell it to my dad with his 9 mpg Chevy C20. I'll keep my 32 mpg Ranger thanks...

I intend to use at least one of these reported events as training. I work with electric drive off highway vehicles. With these vehicles the primary means of slowing the truck is the retard system which is regenerative.

Standard procedure if you are going too fast as you go over the ramp is to apply the service brake as if you want to stop the vehicle. Feathering the brake will only overheat it.

The same goes for Prius or other passenger vehicles. One (Pruis) event was reported in Australia a couple of days ago and when the copper involved instructed the driver how to use his brakes, despite them already being overheated, the vehicle started to come under control enough for the copper to utilise bis own vehicle brakes to complete the stop.

Your mention of the correct use of brakes is why I've given you a GA.

Every day I see drivers (especially of automatics) abusing their brakes. When I'm coming home from the Coalfields I see a row of brake lights illuminated all the way down the range (12% gradient). Dropping down a gear seems to be impossible for many "drivers".

I dissagree slightly with your comments:-

On my Mitsubishi, I get between 3 and 5 brakings with good help from the booster before its empty.

So if you pump the pedal (not needed with ABS!, you will empty the reservoir quickly.

But if you stay on the pedal as hard as you can, you won`t empty it (unless you have vacuum leaks or some other unfixed problem of course!)

Diesel & Turbo diesel and most/but probably not all petrol turbo cars have a separate vacuum pump that actually works better at high revs......useful in such cases!!

On some cars its part of the alternator (at least on the ones that I have looked at!!)

Most passenger cars suffer from underrated brakes. While the vacuum is one issue, brake fade from excessive heat quickly compounds the the problem to the point where the brakes act at a fraction of their capacity. Under extreme duress, drivers tend to apply huge amounts of brake pressure due to adrenalin rushes, which help to overcome some of the loss of vacuum, but brake fade is another matter.

That issue exists with the brand new brakes. Worn or partially worn brakes aggravate the issue further. When brakes heat up the brake fluid actually boils inside the caliper.

Under ideal conditions, the brake rotors should act as a heat sink and the pads as a heat shield.

It always amazes me when I look at all these passenger cars and see these tiny little rotors and the tendency for people to ride those brakes. Small brakes, worn pads and rotors, and bad driving habits all contribute to the problem.

I guess another issue is that people really could not be bothered to really learn about driving defensively. We have reached a stage where one of the more important car buying criteria is the number of cup holders, the radio and entertainment center, interior comfort, color, status, and the ability to run over pot holes and rubbermaid trash cans without feeling them.

People just want to exert the minimal effort, without thinking of what happens inside the box, to get from point A to point B in the greatest style and comfort that their money can buy. Most people can't even change their own tire.

In my field of work electronic throttles have been around for quite a while and before that air throttles were used. Cable throttles haven't been on big gear for 40 years at least.

The keyswitch can't turn off the control power until the vehicle has stopped moving. This feature was introduced to protect operators from themselves, preventing the selection of angel gear.

There is however a killswitch, accumulator backed hydraulic brakes and steering and spring applied park brake to complete the safety package. None of these things exist in the average passenger car.

Lack of these items make the idea of a push button start in the "Windows" style look a bit dodgy.

Having laid out the kind of safety features that are part and parcel of Off Highway Vehicles, I now have to say the hardest thing is getting the operators to use the gear correctly. If operators who must be assessed as competent for each piece of gear they drive can't get it right, we probably can't expect too much from Joe Motorist.

I think the idea of a reset or kill switch in a car is going to meet two hurdles.

1. There is the issue of accidental engagement of the kill switch while driving. Yes, there will be lawsuits the moment someone accidentally hit is and causes an accident. Where do you locate it so that it can be easily accessed, yet not accidentally engaged by the driver or an irate passenger. Then there is training to use it (remember, lowest common denominator). Control-Alt-Delete syndrome.

2. From a marketing perspective, who would want to buy a car with a kill switch? It implies that the car isn't safe in the first place and they had to install a backup safety device incase of a catastrophic system failure or a HAL moment. At least that is the perspective of the buying public.

I think the first manufacture that installs a kill switch sill see their sales killed because the perception is that the manufacture is admitting guilt of a dangerous or unpredictable system in the car.

Toyota Applies the Brakes

The company hopes a "smart pedal" will help defuse criticism.

I got a little tangled up in the formatting

so I'll post my comments here

The smart pedal seems to be in effect a kill switch

the omission [in the original designs] was the real fucq up

the alarms & faults are the hardest part of coming up with a comprehensive truth table

Hill start logic etc is certainly not new and you have to wonder why it took a crisis to bring these catch up changes.

The side effect may be to eliminate left foot braking (or at least the effect of it), the hidden villain in all this.

Interesting article, as is the Popular Mechanics one linked to it. This is a proud moment for Toyota -- bringing out technology today that BMW had 22 years ago!

One would hope they come up with something better to call it than "smart pedal." Invites questions like "How friggen smart are these people if it took them so long to figure out that the brakes should override the throttle?"

Let's me see if I have the history right.

1. There is no problem. Bad drivers.
2. Whoops, it's the floor mats: here are some wire ties.
3. Whoops, it's our sticky throttle pedal. This shim might help.
4. Whoops, we forgot to include an override. Our pedal used to be dumb.
5. Whoops, we should not have used Windows 95 for system control. We were going to upgrade to Millenium Edition, but it cost too much.

Well put.

The key switch has worked well as a kill switch and so long as it isolates the power it is a case of, "If it ain't broken don't fix it".

If soft controls continue to be installed (and customers continue to buy them) kill switches or seperate isolators may be the only solution.

There are I'm sure many explainations for crazy things happening involving electronics. Just one intermittent ground connection can drive even the most experienced tech nuts. This is where we are today. I guess we could call it progress. What do you suppose will happen next after sudden acceleration problems?

What do you suppose will happen next after sudden acceleration problems?

Sudden stopping problems?

"I am not willing to trust my software to provide a fail-safe when my life is on the line, and I'm not about to trust anyone else's."

Obviously, you don't fly, drive, take public transportation, rely on emergency medical aid and so on.

You would be amazed at what's around you that is a safety critical device. Beyond aircraft and transportation, but even these contain subtle devices that we take for granted. Do you look both ways every time you cross an intersection that is green? I try to look, but many times you can't see left or right well enough to be certain that nothing is coming nor can you tell if the light has malfunction for the other driver.

If you have an electronic controller in your oven, chances are you rely on embedded controls from blowing up your kitchen when you engage clean mode in your oven. Ever open an oven door when it is in clean mode? The resulting in-rush of oxygen causes a rather spectacular explosion.

Truth is that we rely on life critical software more than we think.

You are right, of course. I don't trust anyone else's software to preserve my life, but I usually don't have a choice about it. I would have liked to have been in on the discussions where it was decided to start putting software in control of power or similar essential systems. Who knows, I might have been persuaded that it was a good idea.

Of course, software isn't the only source of failure in a system, and sometimes there really isn't a choice about putting a CPU on life-support duty. But there needs to be a damn good reason to do so, because software is generally the most complicated and frail part of most systems.

my response is here.

Chris

I have had two related problems, but with BMW's.

In about 1970 a spring disengaged whist I was at a police check point in Zambia and the engine went to full throttle - embarrassing but safe as it was in neutral.

In the UK I had another secondhand BMW but with a solenoid activated throttle that eventually decided life wasn't interesting enough and would race and loiter at will (its).

The solution was to cut out the electronic control and instal manual twin webers, which turned out less hairraising and more fuel efficient.

I shall reply to myself.

The failsafe we have on our cars is the foot operated clutch, and if that failsafe fails we turn the ignition off.

Automatics aren't for real drivers, they're for people like that .... who parked, (I thought) then reversed at high speed with one arm on the steering wheel and the other hand clamped to his ear, just as I jaywalked behind him.

The ratio of automatic to manual transmissions is completely reversed in the US compared to Europe.

Come here and try to get a rental car with a stick.

We'll take Visa, Mastercard, American Express, but no sticks.