>>>>>>http://news.yahoo.com/s/ap/20110208/ap_on_re_us/us_toyota_recalls
>>>>>>
>>>>>>Why didn't they just talk to Woz? Sounds like he has a repro...
>>>>>>
>>>>>>http://gizmodo.com/#!5462004/steve-wozniak-explains-that-faulty-software-caused-his-car-troubles
>>>>>
>>>>>Dunno regarding this -- was reading thread on a message board elsewhere where Woz apparently explained how he ran into the problem. It seems that he was repeatedly hitting the accelerate button on the cruise control (usually this increments the speed by a set amount), and since the car didn't seem to respond, he kept pressing it -- before he knew it the car was "unexpectedly". accelerating up to 80mph.
>>>>
>>>>In electronic terms, this is a case of User Shorted to Ground.
>>>
>>>I awkwardly phrased that. What meant was: apparently the Woz was repeatedly pressing the button rather than holding down the button. In most automobiles that I've driven, holding down the "accelerate" button doesn't continually increment the speed, and that the acceleration doesn't get triggered until you release the button (and usually a moment afterwards -- i.e. there is a time lag. On the other hand, tapping the brake or hitting the cancel button takes effect immediately). I don't have a Prius to see if it behaves the same or not.
>>
>>If you hold the accelerate button I'm pretty sure it will keep incrementing the speed.
>>
>>Of course you can cancel cruise with the flick of the cruise control lever if it is doing something you didn't want.
>
>If it's working correctly :o)

That's one thing that often worries me about DBW (drive-by-wire -- anlaogous to FBW "fly-by-wire" used on modern aircraft). It's been reliable on military and commercial aircraft -- but then they're usually inspected on a regular basis, meaning that if there are problems, they're often spotted before they become serious. When it comes to personal vehicles, it's likely a different story -- there is high probability that they don't get inspected as often as necessary (we probably know at least a few people who neglect regular maintenance such as oil changes or rotating the tires). For those cases I can see that the only "safe" option is to default DBW system to auto-shutdown when a fault is detected -- however that will result in customer perception that car is unreliable.

BTW anybody ever experienced forced system reboot of onboard computer in their car? Pretty weird, as the car seems to go "dead" for a moment when the computer detects problem and reboots, then resumes normal operation a couple seconds later. A friend of mine had that happen in his car -- a bad sensor, coupled with some errors in ROM forced car into a failsafe reboot under a specific set of conditions.

Can you imagine one day in the future, standing outside your vehicle in the cold, trying to convince the computer to let you in ? sort'a like a repeat of a famous scene from "2001"...