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Unintended Acceleration - Find the Cause

2237 messages,  Last post on Feb 26, 2013 at 1:36 AM

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What is this discussion about? Toyota, Hyundai, Lexus, Ford, Audi, Automotive News, Legislation

Messages Page 224 of 224

#2228 of 2237 Mercedes gets into the act by steve_ HOST

Aug 13, 2012 (6:16 am)

Maybe floor mats will just get banned.
 
"Mercedes-Benz is recalling all-season accessory floor mats sold in model year 2012 and 2013 ML-Class vehicles because they could cause the car's gas pedal to get stuck."
 
Mercedes-Benz recalls floor mats from ML-Class (Detroit News)

#2229 of 2237 UA still an issue? by greg128

Aug 28, 2012 (4:47 pm)

just did a bit of math and found the ratio of complaints to NHTSA for Unintended Acceleration to the total number of that car's sales for the last seven years (2006-2012)
  
The results for 4 cars..Sante Fe, Camry, Accord, and Malibu.
  
# of complaints : total sales
Sante Fe - 1 : 6,404
Camry - 1 : 2,960
Accord - 1 : 31,360
Malibu - 1 : 60,640
  
The complaint rate for the Sante Fe is 10x that of the Malibu and the Camry is 20x.
There are plenty of reports coming in for Toyota even after their recall, and Hyundai isn't trending very well either

#2230 of 2237 Re: UA still an issue? [greg128] by greg128

Aug 28, 2012 (6:02 pm)

Replying to: greg128 (Aug 28, 2012 4:47 pm)
If driver error was responsible for UA cases, then it would follow that older drivers would have a higher report rate. However I checked the complaint rate for a car that probably has one of the highest average age buyer - Ford Crown Vic, and a car that should have a relatively much lower age driver - Toyota Prius.
 
#complaints : total sales
Ford Crown Vic - 1 : 26,450
Toyota Prius - 1 : 3,060
 
These complaints are made mostlly only after an accident of some kind and most reported multiple instances before the accident where the accelerator pedal stuck or responded abnormally. I am sure these are only a small percentage of actual occurances of UA.
 
I think it is safe to say that there are definitely instances of driver error where the accelerator is mistaken for the brake, but that does not explain the much higher rate in some makes, even when pedal positions and floor mat placement is taken into account. Luckily this is rare, but apparently real, and in all probabiltiy having something to do the the electronics and computer control.
 
This happened to a couple in their 60's in Korea in a Hyundai Sonata:
 
Sonata UA Video

#2231 of 2237 some lawsuits winding down by steve_ HOST

Feb 24, 2013 (2:14 pm)

"The lawsuit claims that certain Toyota, Scion and Lexus vehicles equipped with electronic throttle control systems (ETCS) are defective and can experience unintended acceleration. As a result, the suit pursues claims for breach of warranties, unjust enrichment, and violations of various state consumer protection statutes. Toyota denies that it has violated any law, denies that it engaged in any and all wrongdoing, and denies that its ETCS is defective. The parties agreed to resolve these matters before these issues were decided by the Court. This settlement does not involve claims of personal injury or property damage."
 
Toyota SUA settlement website

#2232 of 2237 Re: some lawsuits winding down [steve_] by plekto

Feb 24, 2013 (2:39 pm)

Replying to: steve_ (Feb 24, 2013 2:14 pm)
And so no evidence is presented. Everything is under NDA agreements and swept under the rug. This surely doesn't seem to me to be the behavior of a company that's got nothing to hide.
 
BTW, the most likely actual cause was not covered at all in the filing. It's not a bad sensor or bad code. It's nothing mechanical. It's simply that the computer froze up and got locked into doing the last thing it was doing. You didn't have acceleration so much as the throttle stayed exactly in the same position where it was before the computer froze up.
 
This happens to PCs, industrial equipment, and even aerospace components. Sensors and microchips often get stuck in a "livelock" (endless loop of repeating code) scenario when they unexpectedly crash.

#2233 of 2237 Re: some lawsuits winding down [plekto] by steve_ HOST

Feb 24, 2013 (2:49 pm)

Replying to: plekto (Feb 24, 2013 2:39 pm)
You can always opt out and file your own suit.
 
I'm still holding out for tin whiskers myself.

#2234 of 2237 Re: some lawsuits winding down [plekto] by srs_49

Feb 24, 2013 (3:19 pm)

Replying to: plekto (Feb 24, 2013 2:39 pm)
For the past year or so, there has been an examination of Toyota's ECU code by some independent third parties (or maybe they were parties to some of the pending lawsuits, not exactly sure here). This examination took place under a very strict Non Disclosure Agreement (NDA), with very stringent security and associated monitoring and logging arrangements in place so that it would be clear who accessed what. The computer system that provided this service was isolated from the rest of the world - no internet access, email services (except within the secured environment).
 
While the the examination showed no smoking gun, there were many instances of poor programming practices - something that you would not expect to find in code as safety critical as controlling the throttle. From what I heard, the code was certainly not anywhere the robustness that you find on critical flight software for an airliner, for instance.
 
I think that it was because of these findings that Toyota is caving in to the inevitable.
 
None of this is general public knowledge, BTW.

#2235 of 2237 Re: some lawsuits winding down [srs_49] by plekto

Feb 24, 2013 (3:23 pm)

Replying to: srs_49 (Feb 24, 2013 3:19 pm)
BUT... the livelock scenario has absolutely nothing to do with the code.(bad coding aside, of course)
 
Nobody ever has tested the thing for abuse. As in literally hit the thing with a stun gun or physical shock and crash(software/hardware, not THE car) the thing while the car is running. What happens?
 
Think of is as closer to the power supply on your PC. how often has it crashed where doing the three second reset hasn't worked? I bet it has happened to you at least once in your lifetime where you had to unplug the computer from the wall and restart it manually. The biggest tip-off is the start button not working to turn off the car. I suspect that the start button is really a power supply switch and it simply froze up.
 
I do know that if a car was having UA, unplugging the battery lead would kill the engine as it would physically disable the injectors and coil packs regardless of whatever the computer might be trying to tell it to do.
 
Is this Toyota's fault, though? Likely not. Computers crash for all sorts of non-code related reasons and none of them are covered under any warranty or service plan that I know of. So why does this matter to me, then? Because I see the same idiot designs in multiple cars and UA isn't confined to just a few Toyotas, either. The vehicles have to be designed to be fail-safe when it comes to the computers freezing while the car is running.

#2236 of 2237 Re: some lawsuits winding down [plekto] by srs_49

Feb 24, 2013 (4:04 pm)

Replying to: plekto (Feb 24, 2013 3:23 pm)
Computers crash for all sorts of non-code related reasons
 
Maybe, but i bet the large majority of PC crashes/hangups/BSDs are cause by software problems. Improper garbage collection, errant pointers accessing memory it shouldn't, etc are probably at the root of most crashes.
 
none of them are covered under any warranty or service plan that I know of
 
The typical shrink-wrap disclosure you're probably thinking of I don't think applies here. Did your car come with a lengthy EUA (End User Agreement) that says that none of the software on the vehicle is guaranteed to do anything correctly, and that if it does something wrong that causes loss of property or life that the SW vendor is not responsible?

#2237 of 2237 Re: some lawsuits winding down [srs_49] by plekto

Feb 26, 2013 (1:36 am)

Replying to: srs_49 (Feb 24, 2013 4:04 pm)
No, but hardware faults such as bad memory modules are simply covered under the basic warranty. That you lose your data, well, it's never covered.
 
Toyota can't really be sued because of outside influences, corroded wiring harnesses, vibration and shock, and so on. At most, they would be forced to change their design, though, which would be a good thing. But there's no money in that, really, so the lawyers don't bother.
 
ie - what this entire "challenge" was about was not about finding the overall cause (no proper fail-safe designs in any of the drive-by-wire systems), but finding a cause that could end up in Toyota being sued for damages.

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