[quote=Ram;1712438]Here's another one.
This happened at Santee, CA near San Diego, CA.
California Highway Patrol Officer Mark Saylor had given his car to the dealer for servicing. The dealer had given him a a temporary loaner 2009 Lexus ES 350. He was driving that Lexus with three of his family when the accelerator pedal got stuck in the floor mat at 192 km/h.
Shutting off the ignition key would have locked the steering wheel, leaving him unable to steer.
In most modern cars stutting off the ignition does not lock the steering wheel. It is only when you take the key out of the lock assembly the steering gets locked ..... however, I am not sure if this system was in place in the Lexus that you are referring to.
Quote:
Originally Posted by harit
(Post 1713724)
Hey Wasif,
sometimes, but only sometimes, situations are not what they appear to be. Remember, the accelerator was stuck. This has also happened in my Amby. The first thing we did was to kick the accelerator, it could free itself. And then we could press the clutch, or switch of the engine. But here, when you kicked the accelerator, it remained stuck, but now the speed was higher with no chance to slow down. And most probably being an automatic, no clutch to press, and .............bang!
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[quote=S.B.Jatti;1718944]
Quote:
Originally Posted by Ram
(Post 1712438)
In most modern cars shutting off the ignition does not lock the steering wheel. It is only when you take the key out of the lock assembly the steering gets locked ..... however, I am not sure if this system was in place in the Lexus that you are referring to.
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Toyota Motor Company, in an act of conscience, recalled 5.4-million vehicles for sudden unintended acceleration. This is Toyota's largest recall in history!
The US National Highway Traffic Safety Administration (NHTSA) feels that the potential culprits/complicating factors, go beyond floor mats.
The type of accelerator pedal in the Lexus that killed policeman Saylor and his family, used a single hinge on the upper end. That made it harder to get the pedal out from under the floor mat.
The Lexus that policeman Saylor was driving had a keyless ignition, which uses a start/stop button that signals embedded system software to start and stop the engine. There is no traditional key to turn to shut the engine off in an emergency. To turn off the engine when the car is in gear, the embedded system software needs to ensure the ES-350's button is pressed and held down for three seconds.
The NHTSA report found that Saylor was traveling at an estimated 100 mph -- that covers a soccer pitch end-to-end in two seconds.
Clearly the software engine-stop button was a design misfit for the 100 mph speed. Embedded system user-interface design is nontrivial !
You can read the NHTSA's report here:
http://www.safetyresearch.net/Librar...ee_Inspect.pdf
There is an informational video at
Consumer Reports Cars Blog: Toyota may shorten gas pedals in acceleration recall
In final analysis:
The fatal combination was:
- Throttle stuck open,
- Automatic transmission (no manual clutch),
- software engine-stop button (designed delay of 3 sec.),
- obsolete driver training for the car (Airbus phenomenon)
In the Toyota pumping the brake pedal in an accelerating car, causes you to lose hydraulic pressure and power brakes. In a Volkswagen Jetta on the other hand the embedded system causes the brake pedal to override the accelerator pedal.
The embedded system in Chrysler(since 2003), BMW(since 2005), Audi, Mercedes-Benz and Volkswagen cars cuts off a car's acceleration by design intention, if the driver presses the brake.
This embedded system is called, "Smart Pedal". Logic in the ECU programming disregards accelerator input if the brake pedal is pressed while the vehicle is moving.
Toyota will install "Smart Pedal" software too from the 2011 model year.
(Comments welcomed)
Ram
