Again, taking things in context, the whole point of reducing or cutting off fuel flow was to implement a safety to stop a runaway car. To which you posted:
"To stop runaway acceleration it is not necessary to cut off the flow of fuel. Reducing fuel flow to idle levels is more than sufficient. The engine computer controls the flow of fuel to the injectors. For the engine computer to reduce this flow to idle levels does not require any movement of any mechanical linkage."
In which case, what's the point if you're arguing about doing it through the same computer that already regulates the fuel injection and it's undergoing runaway acceleration? I thought the presumption here was a failsafe to cutoff the engine. Clearly, what you need is an entirely seperate cuttoff system. Talking about reducing it to idle is spurious, because the computer that is already managing the fuel flow is presumed to have faulted and is commanding full acceleration. So, how is it now suddenly going to go back to a nice idle?
Guy drives a faily good distance in runaway conditions by repeatedlyi in/out of gear, pulls into dealer with it still doing and smoking hot breaks. That was all over the news and was also cited in this thread.
The guy who demonstrated how he could induce runaway and get 'no code' That demonstration was also all over the news and cited in this thread. And yes, they pulled it out of gear before finally stopping.
Since you are trying to put up strawmen let me curtail your attempt:
Sudden acceleration with no time to react. No problem there. Driver not at fault.
My problem is someone who does have time to react but doesn't - Cop and 3 family members. Clearly driver error that caused the deaths. How many others died due to incompetancy I don't know but I bet there were some.
Sinceyou cannot differentiate between the cause of the runaway and the cause of the deaths I see no point in contineuing..
Take it from the top again and making it simple for you.
Thne cause of the cop/family death:
Runaway - Toyota Deaths - incompetent driver.
Proof of shifting under runaway: You must never watch the news or read this thread very carefully.
Guy gets runaway, does the correct thing (short of shutting it off) - repeatedly goes from drive to neutral and back, pulls into dealers lot with it still happening. All over the news and cited in this thread.
Guy shows how he can induce runaway. Aslo shifts to neutral prior to making a stop. Aslo all over the news and cited in this thread.
Feel free to continue distorting what I have said.
Never claimed that I did but nice try.
Now you are just being totally unreasonable. How about proposing somehow picking up a rock that blocks the shifter.
Really stretching there now.
I repeat. Since it has been proven it can be shifted and noone has come up with even one example of a car that cannot be shifted...'
Sorry if me pointing out reality to you doesn't suit you.
*This* subthread originated from the contention by some fool that trying to stop runaway acceleration by shutting off the flow of fuel was a bad idea because it would supposedly damage the engine. I simply pointed out that it's not necessary to shut it off completely in order to stop runaway acceleration.
It's not up to me to watch the news to prove your claims. You claimed specifically that a Lexus had been brought to a stop by shifting into neutral during runaway conditions. First, on the face of it, this is actually impossible to do, because no one has been able to duplicate the "runaway" condition. So, the best you could be referring to was that it's been proven that a Lexus identical to the one driven by the CA highway patrol officer can be shifted into neutral when traveling 120mph under full throttle. That would be a good start. Link please.
Please point me to where this is in this long thread. I've seen where someone posted about an electronics guy causing full throttle by fooling with some wires and that it did not set any fault code in the computer. I have not seen where he did that while driving and shifted to neutral while going 120mph at full throttle. Maybe I missed something and you can show me where this was stated.
I never claimed that you had said so. But YOU keep insisting that there is loads of evidence that a Lexus can be shifted into neutral under runaway conditions. All I'm asking for is a link to Toyota or anyone else that has done a test that your believe at least closely duplicates the runaway conditions.
Note: That isn't an anecdotal report here that someone shifted their car into neutral going at 50mph, etc.
Why is it unreasonable to expect a forensic investigation of the key components from key cars, like the CA highway patrol officers Lexus? Just because you want to jump to conclusions, everyone else should join you? Is that what the NTSB does with a plane crash?
How would you suggest to get to the bottom of it? Just rely on your speculation as opposed to scientific investigation?
Just point us to a link where it has been proven that you can shift that Lexus into neutral under runaway conditions, as you claim. Of course you can't because no one can duplicate the runaway conditions exactly. But I'll settle for a link to a test going at 100-120mph under full throttle conditions.
Then it should be easy for you to provide us to a link to any source, Toyota, the media, etc where they proved it. First, it should be obvious to even you that they can't actually duplicate the runaway condition, because no one knows what is causing it and exactly what occurs during that period. However, a good starting point would be where the test was done going 120 mph under full throttle. Waiting.......
Perhaps, because we apparently can follow the thread, and filter out the nonsense.
tion.- Hide quoted text -
You need to learn to read threads in context. The whole discussion was focused on cutting off fuel flow to stop the car. There clearly is no point in doing that through the SAME computer that is already controlling the fuel flow.
If by "filter out" you mean "generate" I suppose I'd agree.
Speaking of reading in context ... the context here was the claim by some fool that you couldn't stop runaway acceleration by _shutting off_ fuel flow because to do so would damage the engine. My point _in context_ was that it's not necessary to shut it off completely, only reduce it. I didn't say anything about how, or where, to accomplish that.
So: learn to pay attention to the posts you're responding to. I'm tired of explaining this to you.
Here's a much better source that says you don't know what you're talking about:
formatting link
For background, embedded processors are the computers that are embedded in something else, as opposed to being a desktop, notebook, server, etc. That something else could be your TV, cell phone, microwave, or in this case car. They have a cpu, memory, input/output and execute a program. Here's what they have to say about how many of these are in cars today and it's even more than I would have guessed. I think many here will be surprised at how high the numbers actually are.
"How many embedded processors does your car have? Go ahead, guess. If you've got a late-model luxury sedan, two or three processors might be obvious in the GPS navigation system or the automatic distance control. Yet you'd still be off by a factor of 25 or 50. The current 7- Series BMW and S-class Mercedes boast about 100 processors apiece. A relatively low-profile Volvo still has 50 to 60 baby processors on board. Even a boring low-cost econobox has a few dozen different microprocessors in it. Your transportation appliance probably has more chips than your Internet appliance."
Another unrealistic request. Can you recite exactly what was on the new last Tuesday? The Monday two weeks ago? Can you provide a link? I see a lot of interesting news that has relevance to a conversation I'm having a year later, but I cannot provide the link or citation if requested. I'm sure you can though.
Nothing at all unreasonable about it. Harrry is running around claiming over and over that it's been proven that a Lexus like the one driven by the CA highway patrol officer can be "shifted into neutral in runaway condition" and that this fact has been widely reported. He says it's been everywhere. The TV media routinely have videos or text reports available online on all kinds of current hot topic stuff. Also, newpapers have articles available online. And those things are routinely used to establish facts.
Are you suggesting I just accept as a given his statement about what he claims he saw on TV? Even Harry hasn't told us what car was used, how fast was it going, etc. Is that the new standard here to establish fact? And once again, I'd say that the best he could do would be to show us a link that establishes that a similar car traveling at 120mph can be shifted into neutral, because no one can actually duplicate what is exactly happening in cars at the time they are experiencing the runaway phenomena. But if there is credible proof that the model Lexus the CA patrol officer was driving can be shifted into neutral at 120 mph, that would be an important step. All I'm asking for is a simple link to see it for myself.
That's not what I said - but if, in fact, the wires that happened to short could LEGITIMATELY have a ground potential under normal operating conditions, a code may not be set. (actually, in all likelihood WOULD not be set).
And yes, that would be a "mechanical" problem - although in the electrical system. I would not call it an "electronic" problem.
However, there are very few input signals that would ever have a ground potential. Most inputs are variable voltage between roughly one and five volts. 5 volts is the reference voltage that the signals work from, and the "legitimate" signal is usually something between, say
1/2 and 4 1/2 volts. I do not have the ACTUAL accurate voltage ranges at hand - but that is the basic principal. If the input voltage to the computer is outside the normal range, a fault is recorded and a code can be set. The computer can also "predict" what a reading should be in some cases, and compare the actual reading to what it expects and cause a code if it is wrong.
O2 sensors are a different type of signal in that they are not resistance based, but are a voltage source. However the same basics still apply. An O2 sensor is supposed to "clock" from roughly 0 to 1.1 volts. The higher the voltage, the richer the exhaust(less oxygen) , with a chemically correct mixture being roughly 0.45 volts. A standard narrow band sensor has a steep "knee" to the signal so is not terribly accurate, but can tell if it is too rich, or too lean, and the computer bounces the mixture from rich to lean around that point. Just happens the catalytic converter likes that, as it alternately absorbs oxygen and oxydizes carbon (oxidation/reduction catalyst) This is one place the "prediction" comes in. The front O2 sensor sees a varying voltage, and the rear sensor is supposed to see less variation. If it sees the right reduction in swing it knows the catalyst is working. If it sees too much swing, it knows it is not working. The computer also knows how many "counts" or crossings to expect under given conditions, and knows there is a problem with the sensor when the number of counts per unit time is too low, or if the voltage swing is too small so it can set an O2 sensor failure code.
All this to say that the system of "fault codes" is NOT perfect and is not designed to cover every possible eventuality. It is really designed to predict emission control ineffectiveness more than anything else, and to give someone with some understanding of the system a place to start in troubleshooting what is a very complex control and feedback system.
And the computer can NOT, at this point, diagnose itself.
3 computers are required to do this, with all three having an even "vote". If two agree, and one dissagrees, it is assumed the dissagreeing computer is at fault.
A simple "dual redundant"ystem is not fail-safe.
VERY easy to do. Simply apply a "full throttle" signal to the fly-by-wire throttle input, or cause the cruise control "accellerate" input to be "active". Both could be legitimate inputs, with full throttle (or at least opening throttle) being a legitimate output.
Now, if that input were to be asserted with the transmission in neutral, the computer would attempt to limit the RPM to protect the engine. If the open throttle signal, in gear, did not create an increase in speed on the vehicle speed sensor (VSS) and DID create a difference in speed from the crankshaft and/or camshaft sensors (engine tach signal) he computer could also throw a code to say the transmission or torque converter had a problem. The computer reads both the crankshaft speed and the transmission input speed so it can tell if the lockup torque converter is working properly.
Extremely slim chance that any 2 wires in the harness, if connected together, would cause the problem without a code, and an even smaller chance that they would be next to each other in the harness, AND be subject to damage under "normal useage", if at all.
IF there is a problem electronically it is likely to be one of 3 things. A faulty sensor A faulty component in the computer or A "bug" in the code.
A "bug" would generally be universal - meaning it would occurr in virtually all of a given model/option because the firmware is "common" to all of a type.
A faulty component OR a faulty sensor would be more likely - but you would expect them to become "predictable" because failures usually get worse very quickly, like an avalanche, when they start - and are usually somewhat temperature related.
To this point there does not appear to be any kind of a pattern that would point towards anything with any degree of certainty.
I used to do a LOT of system troubleshooting during my years as an automotive technician - and now do a fair amount in the computer field. (as well as some more basic electronic repairs - fixed 2 GPS units last weekend, and 2 inoperative handheld aviation radios yesterday).
The FACT is the law requires there be a mechanical way to put a cat out of gear, and ALL cars with automatic transmissions, to this day, have a "manual valve" controled by a linkage to do this. The only automatic car in history that I cannot say for 100% positive had this feature was the electric shifted Edsel with the buttons in the steering wheel (made for only 2 years) and the Packard Ultramatic, which is the only car in history that could NOT be shifted into neutral at speed.
Both of these had come and gone before automotive safety legislation caught up with them.
Don't need a test if you understand how the car is built. There is NO LOCKOUT that can prevent the shifter fom moving to neutral at speed and yet allow the car to be put in neutral at a stop.
Any mechanical FAILURE that would prevent shifting to neutral at speed would also prevent going to neutral at a stop. The brake/shifter interlock only prevents shifting OUT OF PARK without the brake pedal depressed - and even IF it could control the movement into neutral fron either drive or reverse (the only options) stepping on the brake would allow the shifter to be moved.
Having had many transmissions apart, including electrically shifted, electronic controlled units, the only electical or electronic controls in today's automatics are electrically operated solenoid valves that control the flow of hydraulic fluid under pressure to the various clutches and brakes that control the shifting of the planetary gear sets. There are no electromechanical devices that interface with the manual valve control which has ULTIMATE CONTROL of the transmission. NO combination of sticky, faulty, or missapplied solenoids could cause the transmission to transmit driving force to the wheels with the manual valve in the neutral position.
That, when it exists, is in the shifter assembly itself - not the tranny, and is called a brake/shifter interlock. Requires the brake to be depressed to put the vehicle into or out of PARK ONLY.
Because there is a LOT more affecting an airplane's flight than there is affecting the operation of a motor vehicle. Aerodynamics are CRITICAL, as is structural strength and loading - which can be affected by so MANY different parameters. A little bit of ice can totally destroy the lifting capability of an airfoil (particularly the now-common "laminar" airfoils) - and by the time investigators get there, the ice is long gone.
By the way - I am also building an airplane.
I'd tell him to his face if he were still alive - even if he was "carrying" There is NO EXCUSE for the death of the Chippy and his family other than gross stupidity in the face of adversity.
Well, I happen to know that the engine and transmission controls are "one computer" . The climate control, air bags, radio, compass, etc are another "computer". Not sure if current Toyota practice is to put the ABS in the BCM or the BCM - used to be PCM, along with traction control..
As far as having more than one cpu in a box making it more than one computer, what do you call a "computer" with a quad core duo intell processor? 8 computers???????
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