TORRANCE, California — In a public relations offensive on Monday that seemed as carefully calculated as Tiger Woods' recent appearance, Toyota rolled out five highly technical videos designed to reassure skeptics that its vehicles are safe and that it is paying attention to claims of unintended acceleration. The videos — and Monday's 90-minute conference call with reporters — come in advance of Congress calling the Japanese automaker on the carpet this week.
Monday's appearance by Toyota's spin doctors also comes just hours after media reports that federal prosecutors have opened a criminal investigation into Toyota's safety problems. Toyota acknowledged on Monday that it has received a subpoena from a federal grand jury in New York seeking documents related to unintended acceleration in its vehicles and the braking system of the popular Prius hybrid.
The ground rules for Monday's conference call and Webinar with Toyota were strict and laid out at the beginning of the event. "Our presenters do not have information on other aspects of the unintended-acceleration debate," said Toyota spokesman John Hanson. "We will not take off-topic questions, nor will we comment on upcoming congressional hearings."
He urged reporters to "consider science, rather than suggestion, in the debate on these matters." Hanson also emphasized that "the issue of unintended acceleration has been a part of the auto industry for decades."
The five technical videos (combined by IL into one video above) — which were decidedly not warm and fuzzy — seemed aimed more at engineers than the general public who are worried about the safety of their Toyota vehicles. They were filled with jargon, such as "closed-loop feedback" and "throttle valve opening angle." The video was designed to show how Toyota is testing the effect of electromagnetic interference from outside sources on vehicles, has no soundtrack and was narrated for reporters by Kristen Tabar from the Toyota Technical Center USA. She said Toyota has "never found any evidence" that electromagnetic interference can trigger unintended acceleration.
The video was designed to enumerate the fail-safe systems built into Toyota vehicles. One section, entitled "what if," underscored that "maximum driving speed and acceleration will be limited" if there is a problem with vehicle sensors or if wiring is damaged.
"These videos and animation show the confidence we have in our engine management system on all of our vehicles," said Paul Williamsen of the University of Toyota.
Williamsen noted that Toyota's fail-safe systems for electronic throttle control are "enacted in less than 4 milliseconds.
"We're talking inches of vehicle motion before we can make those adjustments," he said. "In every case, the vehicle brake system can be relied upon to bring the vehicle to a stop."
When asked the simple question "what is happening" to its vehicles if it has implemented numerous fail-safe systems and ruled out electronic gremlins, Hanson offered this explanation: "We don't rule anything out. We are at the same place we've been at for quite a long time. To investigate all reports of unwanted acceleration. Besides selling cars and trucks, we investigate complaints. If there's a problem, we try to find a way to fix it."
He added: "We will investigate any and all claims of unintended acceleration."
Inside Line says: At the very least, the new Toyota videos should be able to lull you to sleep, should you be suffering from insomnia as a result of fears about unintended acceleration. — Anita Lienert, Correspondent
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sparkplug8 says:
10:14 PM, 03/25/2010
An additional comment, based on a real computer problem from copier development experience at Eastman Kodak:
When the CPU became overloaded due to other priority inputs occurring at a 50:1 rate over expectation, the CPU could not shut down the drive motor when the cover was opened, actuating that CPU input. After a technician got her hair caught in the mechanism, a kill switch was designed into the cover for the AC line to the motor.
The suggestion here is that a kill switch is needed on the brake pedal to effectively return the engine throttle to idle whenever the brake is engaged-- similar to taking the right foot off the accelerator to press the brake in a mechanically more certain system. That way, the CPU and its relays would not have to function to ensure throttle movement to idle. This is exactly how older vehicles had their cruise control units wired-- they shut off when the brake is pushed. Very early units also incorporated a vacuum relief "switch" at the brake pedal, for redundancy when a vacuum source actuated the throttle.
For the Prius, possibly more complicated, but the result must be the same.
sparkplug8 says:
07:13 AM, 03/24/2010
From the news reports and an interview I watched with a driver who experienced the problem and lived to talk about it, I would suspect that the accelerator pedal unit is being over-stressed when the driver mashes the pedal hard, to the point of failure of the sensor section CONNECTION to the pedal itself.
In that case, the sensors could be "correctly" indicating a full-throttle request, but may be floating in the assembly, at best. The pedal could return to idle request position, but the sensors still would be in that wide-open position, within the assembly.
Pictures of the assemblies shown in another on-line article indicate that much of the structure is plastic, hardly able to withstand the lead foot of a male driver if appropriate external stops are not in place. If internal stops are, in fact, part of the SENSOR portion of the unit, that could cause the CONNECTION, such as a spline, or plastic shaft, OR THE END OF THE PEDAL ITSELF, to be sheared. Subsequently, there would be no connection to return the SENSORS to the idle request position.
topper57 says:
09:37 AM, 03/11/2010
As an auto mechanic for 35 years and as one who has raced automobiles professionally, the entire dynamic of ETC (electronic throttle control) seems completely insane. In many classes of racing not only is solid throttle inkage or a push/pull cable required, a toe strap is also required that can pull the throtle pedal up in case it gets stuck or a return spring fails (at least two springs are always required).
I experimented in the 1990's with a launch control system for drag racing that would launch the car off the starting line triggered by sensing the starting lights (christmas tree as it is called- and BTW it worked).
Paramount was to make it fail-safe so it was impossible for the vehicle to run away unintended.
I achieved this by arranging the electric solenoid so that it could not open the throttle, but instead would hold it closed. The starting launch was enabled by the driver having to manually push on the throttle before the start, and the electronics simply released the pedal and allowed it to open triggered by the signal of the starting lights.
Assuming that the most important reasons for ETC is to allow the computer to reduce or close the throttle in response to driving, economy, emissions demands, etc., I believe the only reliable long term fix for ALL AUTOMOBILES is to engineer a similar failsafe in their ETC systems.
I.E. the electronics would not be able to open the throttle, that could only be done by the driver pressing on the throttle via mechanical or cable linkage.
However the electronics would be able to "back off" or close the throttle to achieve the same advantages of the ETC system, with no possibility that errant electrons running around in semi conductors or defective or damaged wiring could cause it to open.
Simply put, the driver or the electronics could close the throttle, but only the mechanical linkage could open it. I am amazed that no one has mentioned this yet.
orionca says:
10:50 PM, 03/10/2010
There are several obvious fault points from the presentation. If both pedal sensors send a correct voltage the ECM will open or close the throttle according to its algoritm. However if they send incorrect signals that are proportionately correct - as if the driver had slammed the pedal to the floor - the ECM would have no choice but to assume there was an order to accelerate the vehicle.
If the throttle sensors failed the ECM should detect a discrepancy between the pedal commands and the throttle opening and cut power to the throttle motor. The fuel injector sensors would have to fail, too, if the throttle sensors said they were OK but too much fuel was flowing into the injection system so we can rule that out for the moment.
If the main CPU and sub-CPU are indeed independent of each other a non-matching signal sent by the one would immediately cause the other to put the throttle in failsafe mode. This assumes the two units are indeed operating independently. It's possible that a sneak-signal between the two could cause a simultaneous fault in the other, however it would be incredibly unlikely that the simultatenous fault would ALWAYS be towards sudden acceleration. More likely the throttle would stick in the current position or oscillate wildly w/o regard to how the pedal was pressed.
I would say the problem is almost certainly in the pedal. Either the pedal is getting stuck to the floor or the sensors are somehow simultaneously failing in the "FULL THROTTLE" position. There'd have to be some kind of mechanism to saturate both sensors simultaneously and non-transiently to send the "FULL THROTTLE" command regardless of pedal position. What that could be I dunno.
ibell63 says:
12:07 AM, 03/09/2010
This is a very nice video that Toyota has put together, and i'm glad that they are openly describing their electronic throttle control system in detail.
That said, I can pick out one issue with the system as described. Working in IT, I know that in certain situations, processors can hang (or freeze) in which the outputs sent from them can also freeze at a value. The problem with this system is that one processor (The "main or control CPU" as described in the video) is in complete direct control of the throttle motor.
What happens if this processor freezes while the vehicle is at full throttle? In this case, the sub processor doesn't matter, because if the main processor freezes, it's not going to be able to react to any sort of "watchdog signal". According to the video, the sub processor doesn't have direct control over the throttle motor (all it gets are inputs, and the "watchdog signal"), so it can't directly change a faulty (frozen) signal outputed by the "main or control CPU".
What I think is happening here with these vehicles is the main CPU in the ECM is freezing at a very bad time, like when the throttle is at or near 100%, which renders all of the fail safes described in this video useless (since they all rely on this main CPU not being frozen).
The solution to this would be to have an additional system OUTSIDE of the ECM that is also in DIRECT CONTROL of the throttle motor that can CHECK THE LOGIC of the ECM's main CPU. This outside system should act only as a switch, either staying open and allowing the signal from the ECM to control the throttle, or cutting it completely, so that the throttle is returned to idle by the spring.
jmaroun says:
11:45 PM, 02/23/2010
As a practicing electrical engineer for over 12 years, I can tell you that I smell a cover up from that presentation. I believe that Toyota has not been totally forthcomming with it's knowledge of the problem. The presentation attempts to appear detailed and technical, however they leave their theories on how forced accellerations could or might occur, leaving the burden to the outside public who is not as familiar with their desings. I can't believe they have NO clue as to what is causing the accellerations or at least what Might be cuasing it. That is disingenuous and utterly dissappointing! They're trying to hide behind ignorance but that in itself is a sign of incompetence at best, and outright deception in the worst case. Only junior engineers and interns can to plead innocence via ignorance and get away with it sometimes. Toyota can not use this excuse. I feel that the ECU micro controller software should be provided to the federal government for inspection by experts. It is sad to see this, but the safety of the public is at stake.
jepontiac says:
09:09 PM, 02/23/2010
one more thing....star safety just happens to match up pretty nicely with NHTSA upcoming regs for all new cars.
jepontiac says:
09:07 PM, 02/23/2010
arock...star safety is a marketing and PR invention. Is it leading to safer cars? Sure it is. But please don't make Toyota look like some altruistic saint. This is ploy to make money, and the recent documents leaked prove that even the great Toyota is in it for one thing, the dough.
arock says:
04:15 PM, 02/23/2010
Toyota is the first company(other than the companies who make luxury brands BMW/Mercedes and others) to bring star safety system as a standard feature in most of its cars starting 2004 that includes a combination of 4 wheel Disk Breaks, ABS. traction control system, stability control system (VSC/VDC) while others as of this moment while I am writing are still charging extra for ABS the most basic feature in todays car. They have promised to bring star safety in every car in their line up before 2011 and they are keeping up their word by giving star safety in all the new models they are releasing. That explains their real intention towards people's safety(there is no real compulsion for them to give all those features (safety features) free of cost while others were charging extra for that, including other Japanese companies) . There is really nothing they have to prove to substantiate this. This is a company who invented cross overs with RAV4, Highlander and now VENZA.
shahgtr says:
03:29 PM, 02/23/2010
Haha University of Toyota, what do they do there? Learn how to make dangerous cars?