Possible Causes of TCH Unintended Acceleration

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  #31  
Old 03-16-2010, 08:17 AM
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Default Re: Possible Causes of TCH Unintended Acceleration

Washington Post... "Masters of the Obvious!"
 
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Old 03-16-2010, 08:32 AM
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Default Re: Possible Causes of TCH Unintended Acceleration

You missed the lawyer's novel assertion...

..."This problem is sort of a ghost in the machine that is the Toyota system," Gomez said Sunday. "It doesn't leave a fault code, it doesn't leave a footprint and you can't make it happen upon demand."...
(sounds like he should be working on global warming cases)

and Toyota's deft handling of the issue

"We're not saying Mr. Sikes is wrong or that he lied..." ---
"The chance of them both going wrong, plus the fact that the signal is bad, it just seems very, very, very remote," Hoff said. "Could it happen? Statistically, yes. But it just doesn't seem very likely."
 
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Old 03-16-2010, 11:47 AM
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Default Re: Possible Causes of TCH Unintended Acceleration

Don't snort your coffee on your keyboard!!!!

http://jalopnik.com/5494444/feds-stu...by-cosmic-rays
 
  #34  
Old 03-16-2010, 06:22 PM
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Default Re: Possible Causes of TCH Unintended Acceleration

Originally Posted by Old-Crows
Don't snort your coffee on your keyboard!!!!

http://jalopnik.com/5494444/feds-stu...by-cosmic-rays


I don't give a crap what anyone says, anyone owning one of these cars took a giant hit on value and wait til the insurance premiums go out of site due to all the ledigation!
 
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Old 03-16-2010, 06:34 PM
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Default Re: Possible Causes of TCH Unintended Acceleration

No expert here, but the cost of insurance is due to the loss experience for the model, so unless people are smacking these into telephone poles, the cost should be stable. As to resale value, if anyone thought of these as investments, well they're going to be disappointed. In 6 months the furor will die down and news will come out that the issue (if there is one) is an industry wide phenomenon as Ford, GM, etc. will similarly recall their cars. The 'stigma' of Toyota will wear off. Toyota's are selling very well, despite the news.
Best to sit back, put both hands on the wheel and enjoy the road, don't worry about the small stuff.
 
  #36  
Old 03-16-2010, 08:17 PM
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Default Re: Possible Causes of TCH Unintended Acceleration

Originally Posted by haroldo
No expert here, but the cost of insurance is due to the loss experience for the model, so unless people are smacking these into telephone poles, the cost should be stable. As to resale value, if anyone thought of these as investments, well they're going to be disappointed. In 6 months the furor will die down and news will come out that the issue (if there is one) is an industry wide phenomenon as Ford, GM, etc. will similarly recall their cars. The 'stigma' of Toyota will wear off. Toyota's are selling very well, despite the news.
Best to sit back, put both hands on the wheel and enjoy the road, don't worry about the small stuff.
That's my plan and I'm stickin' to it!!!
 
  #37  
Old 03-17-2010, 10:26 AM
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Default Re: Possible Causes of TCH Unintended Acceleration

The HSD control ECU's firmware is somehow "stuck" continuously executing the "set/accel" cruise control sub-routine and therefore ignoring all other inputs.
 
  #38  
Old 03-17-2010, 06:00 PM
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Default Re: Possible Causes of TCH Unintended Acceleration

Originally Posted by wwest
The HSD control ECU's firmware is somehow "stuck" continuously executing the "set/accel" cruise control sub-routine and therefore ignoring all other inputs.
Someone recently described this quite simply as being like a desktop computer that "freezes" all functions, but an animated GIF is still running in an endless loop.

I also stumbled across the Jalopnik article referenced a few posts back about "Cosmic Rays" and "Bit Flips". Willard, with your background, perhaps you could opine on that wild idea.
 
  #39  
Old 03-18-2010, 09:24 AM
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Default Re: Possible Causes of TCH Unintended Acceleration

Many years ago now it was discovered that the geometry, "trace size", of solid state integrated dynamic memories had gotten so tiny that an alpha particle "stike" in just the right place would momentarily "upset" the memory contents. I believe it was then discovered that this was due to radiation capable molecules (radium, U235..?) being inadvertently embedded within the IC's plastic or ceramic case.

But I remain of the opinion, STRONG opinion, that the Sikes incident was the result of a coding flaw that resulted in the HSD control computer getting "stuck" executing ONLY the "set/accel" function. That might also explain the Saylor and Smith runaway engine incidents. In the Sikes instance it is clear from Toyota's own documentation that the skid control computer might not make full use of frictional braking even with the driver applying EXTREME pressure to the brake pedal.

The Prius even has a spring loaded "stroke simulator" so that the brake pedal has the right "feel" even though the resulting brake fluid pressure is not reaching the brake calipers.
 
  #40  
Old 03-18-2010, 12:35 PM
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Default Re: Possible Causes of TCH Unintended Acceleration

I have a problem giving Sikes the benefit of the doubt here.

1) He is in a runaway situation for 20+ minutes with the brakes not responding, but when the CHP arrives he can now stop the vehicle.

2) This is on '07 Prius which I believe this person owned since new and he was unable/unwilling to put it in to Neutral.

3) Again after ~3 years of ownership, and a Toyota statement to just turn the car off if a UA happens, Sikes again is too afraid to do that because 'it might flip'

4) So with 2) & 3) he has these fears, but he will reach down and see if he can move a floor mat and is willing to take his chances driving 90+mph for over 20 min on a winding road while on the phone with a 911 operator.

All that and techs from NHTSA and Toyota didn't find (so far) anything wrong with the car and they said that the condition of the brakes was not consistent with someone pressing on them for 20 minutes at high speed.
 


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