Herbert Graf wrote:
> Agreed, "drive by wire" scares people, yet I've seen mechanical
> throttle cables seized in the WOT position, and yet people aren't
> worried about that.

Yes, this has actually happened to me in a 1972 Ford Pinto long ago.  I was
going up a hill and had to floor the gas, as was usual for going up a hill
in that car.  When I tried to slow down at a stop light, I of course took my
foot off the gas and was expecting the hill to mostly slow the car.  Instead
the car kept going.  It does take a little time for this to sink in since
it's not a common occurence.  I had some room in front of me so I turned off
the ignition, stepped on the clutch, shifted to neutral, and eventually
stepped on the brake.

Stopping wasn't the problem.  Getting started again was, since the engine
got a little flooded and the throttle was stuck wide open.  There were too
many cars around to try to roll backwards to the side of the road, so I
popped the hood in the middle of the street.  It didn't take long to
discover that a linkage had come loose from the automatic choke.  This
allowed a cam to dangle free.  If everything bounced just right when the
throttle was wide open, the automatic choke cam would get wedged and hold
the throttle in the wide open position.

The throttle sticking open in this way happened at least one other time
while I owned the car.

I doubt drive by wire systems are inherently and more dangerous.


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000.
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist