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Unintended Acceleration - Find the Cause



  • It's not an argument--with ABS it's a fact---pumping the brakes defeats the ABS function.

    What you do is jump on the pedal with both feet if you have to*

    *exception---gravel roads---that's where you might get more results by pumping.
  • gagricegagrice San DiegoPosts: 28,680
    edited December 2013
    Also on Ice. We disabled the ABS when possible as they caused loss of control on ice. Light taps on ice work better than full on braking. I spent 8 months per year driving on ice in the Arctic for 25 years. No accidents or slide off into the ditches. For me the cop that got killed, presents more questions than answers. I drive that stretch about once a week and look at the spot they ended up and wonder what he could have done.
  • Stever@EdmundsStever@Edmunds YooperlandPosts: 38,985
    Re pumping the brakes, I was thinking more of this scenario from that plaintiff's lawyer's site, Safety Research & Strategies.

    "with the throttle plate open, the vacuum power assist of the braking system cannot be replenished and the effectiveness of the brakes is reduced significantly and that brake pedal force in excess of 150 pounds was required to stop the vehicle, compared to 30 pounds required when the vehicle is operating normally."
  • Yes but the vacuum does not dissipate with steady brake pressure. If he pumped the brakes many times over, then he caused the brakes to be difficult (but by no means impossible) to operate because he didn't follow the proper procedure for braking with ABS. This should have been part of his training.
  • gagricegagrice San DiegoPosts: 28,680
    As a veteran of the CA HP he probably learned the pre ABS braking method. Old habits are hard to break. I hated driving my 1973 Subaru and 78 Honda Accord on ice and snow. I never got used to FWD on slick surfaces. Give me rear wheel or AWD. Then I never liked driving sedans much anyway.
  • kernickkernick Posts: 4,072
    Busiris: Just because something "could" happen in no way means it "will", or "has" happened.

    Me: That's exactly how I feel when I walk into a convenience store and buy a lottery ticket. The same probability-theory applies to most car defects. Maybe 20 - 2,000, of hundreds of thousands of models will actually have the same variables actually align to trigger the problem. The defect is a "potential" not an "absolute". But that does not mean that because it is not easily duplicated, or it is not understood how to duplicate it, that the events - though improbable are not happening.

    Given the number of patches and upgrades I've received for years on my computers, I guess there are a lot of flaws in the software.
  • For "Fly-By-Wire" vehicles we already know the CAUSE of unintended malfunctions, its close proximity broadcasting of digital signals by RF devices such as CELL PHONES Its why aircraft do NOT permit CELL PHONEs onboard an aircraft that is taxing to takeoff In USA cell phone frequency range is ~800MHz wherein wavelength = c, speed of light / frequency, to give a wavelength of ~14". Any T-shaped FM antennae picks up this signal IF top of T is 14" or half of the T is 7". Does a half wave antennae protrude into an auto cockpit? Can we say "Turn Signal" wherein a 7" length of wire is connected to the CRUISE CONTROL> When Mrs. Rhonda Smith testified in congress that her runaway Toyota dropped to 35mph after she called her husband, that "God Intervened". Sorry but her CELL PHONE intervened NO ONE in congress nor gov't DOT asked the next logical question- When no. did you dial? Why? Last thing gov't needs is another car co. to Bail Out as NO ONE would buy a Toyota So we have another GOV'T COVERUP, which only adds fuel to the firestorm that Americans are coming to the realization that "AMERICA is a BIG CORPORATE LIE" sorry about that

  • Stever@EdmundsStever@Edmunds YooperlandPosts: 38,985
    edited February 7

    Finally, a verified mechanical cause for once.

    "Fiat Chrysler Automobiles NV said it is recalling its 2014 Ram ProMaster vans to resolve a condition that may allow an accelerator pedal to stick in the wide-open position if force is applied at an angle."

    Chrysler recalling nearly 10,000 vans for pedal problem (Detroit News)

  • Stever@EdmundsStever@Edmunds YooperlandPosts: 38,985

    Remember this guy? - now we have "the Gilbert Mechanism."

    "Tin whiskers can wreak havoc in electronics ranging from simple digital watches to modern space satellites, from pacemakers to nuclear power plants. NASA studies them closely. And the problem in Toyota’s pedal sensor sounded like it might be caused by tin whiskers, said NASA physicist Henning Leidecker.

    Leidecker and other NASA scientists were so taken by Gilbert’s research that they call the unique sequence of events required for a pedal sensor to short out “the Gilbert Mechanism.”

    “I think he’s a hero. What he found was ingenious,” Leidecker said."

    A Carbondale professor, runaway Toyotas and the hunt for 'tin whiskers' (

  • MrShift@EdmundsMrShift@Edmunds Posts: 43,664

    Well it's not good science, but it might lead to good science.

  • Stever@EdmundsStever@Edmunds YooperlandPosts: 38,985
    edited April 20

    Yeah, you can't trust those NASA physicists as far as you can throw them. Leidecker is probably measuring those whiskers in inches and then calculating their growth in metric. B)

  • MrShift@EdmundsMrShift@Edmunds Posts: 43,664
    edited April 20

    The theory has not been reproducible is what I mean. All "theories" in science are rigorously attacked and either defeated or proven. When NASA had the theory that o-rings blew up the Challenger, they proved it.

    So, until someone retrieves a car wrecked by a UA incident, and finds tin whiskers, and then puts that part in a normal car and it goes UA, then nothing is proven.

    Right now, all they know is that they can artificially induce the car to accelerate, which is INTERESTING, but not the smoking gun by a long shot.

    Is it really "bad" science? No, only if you claim that it has solved the problem---then it's really bad science.

  • Stever@EdmundsStever@Edmunds YooperlandPosts: 38,985

    NASA didn't understand the o-ring problem from the get go, or at least NASA's management ignored the warnings (starting to sound a bit like GM's ignition switch issue). (wikipedia)

    I haven't seen a theory I like better (and that includes the "all the drivers were idiots" theory).

  • fintailfintail Posts: 32,923

    I'll go with the idiot driver theory. Spend a few hours in the Seattle area observing Camrys and Prius - it will make sense.

  • MrShift@EdmundsMrShift@Edmunds Posts: 43,664

    I agree. The idiot driver theory is simpler, more logical, and well...we've seen it before.

    but alas, not easy to test the idiot driver theory---I mean, would you have to find volunteers who have had 10 previous UA incidents? (hey, that might work!)

    NASA fully understood the o-ring problem but they never had launched in weather that cold before. The actual PROOF of the o-ring theory was captured, of course, on film.

    I think this wasn't even a "theory"--they knew right after it blew up.

    Theories need to withstand relentless bombardment to be proven true or false. Until someone can get a Toyota to UA time after time with a whiskers-infected device, I'm not buying it.

    All Mr. Science "proved" was that you could induce a UA without throwing a trouble code--and that is a significant thing to find out--but it's not at all "proving" UA.

  • Stever@EdmundsStever@Edmunds YooperlandPosts: 38,985

    Well, you'd have to grow and regrow the whiskers. They're a lot more fragile than even O-rings.

  • MrShift@EdmundsMrShift@Edmunds Posts: 43,664

    See? Already you're making excuses for the theory :)

    So they "cause" UA and then they disappear?

    Lame, Steve. Try again.

  • Stever@EdmundsStever@Edmunds YooperlandPosts: 38,985
    edited April 20

    It's all in my link - "But Leidecker, one of the investigators, said the findings were more limited. Tin whiskers are elusive and easily destroyed". (Emphasis mine)

    Maybe you missed this part too:

    "Toyota redesigned its pedal sensor in 2007 and again in 2008, expressly to eliminate the risk of tin whiskers."

  • MrShift@EdmundsMrShift@Edmunds Posts: 43,664
    edited April 20

    Still doesn't prove it by the scientific method. All speculation even though it 'sounds plausible'.

    Let's examine it.

    I think Steve destroyed my computer by doing something wrong. My computer has crashed.

    Steve had just worked on my computer, and this is why I suspect him. He denies it and it sounds like he's covering up. He may have done it accidentally but he won't let me access his work logs. Now he's working on my friend's computer but I notice he's not using the same methods as he did with mine.

    this is very suspicious. I have created a way to re-construct what I think Steve did and it makes sense.

    THEREFORE, Steve is guilty.

  • Stever@EdmundsStever@Edmunds YooperlandPosts: 38,985
    edited 12:22AM

    It's clear that tin whiskers break things (including NASA satellites which have the lack of gravity exacerbating the problem). The only question left is whether the problem caused any SUA events. The scenario is plausible enough that Toyota changed the sensors to try to avoid the problem.

    USC doctoral student unravels ‘tin whisker’ mystery (

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