Date:         Wed, 13 Mar 1996 12:51:19 -0800
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         wabbott@mtest.teradyne.com (William Abbott)
Subject:      Audi problems, FI chips

	Tim,
	Dennis Haynes is right, without no electronic fuel injection
fault can overcome the position of the throttle.

	Under controlled conditions, 'unintended acceleration' of an Audi
was only generated when a driver, distracted, put their foot on
the gas THINKING it was the brake. The harder they pushed, the faster
it went. 
	A study was done with a passenger/observer equipped with
a magic box which could, at will, open the throttle regardless of driver 
input. Multiple drivers had no difficulty controlling the cars when the 
engine suddenly rev'ed up. Then one driver created an 'unintended 
acceleration' incident with, you guessed it, their feet.
	
	A stupid design problem IMHO, in the size and placement of
the pedals. I recall at least one child got killed by being squished  
between car and garage wall. But not an engine defect.

	Reflex muscle movements are powerful and hard to overcome.
I test-drove a friends automatic BMW and 'put in the clutch' with
my left foot while rounding a corner. This motion put my foot
against the brake pedal and that slowed the car dramaticly. Reflex
took over and I mashed the brake, with my 'clutch' foot. Made for
an interesting test of the ABS brakes. No skid mark. Inertial reel
seat belts worked too. Boy was I embarased. 
	So I didn't complain when he drove my Corrado at max acceleration
up Marin Avenue in Albany/Berkeley. Anyway, I dug it!

	Whomever told you that layers in semiconductor chips can crack 
and the chip remain in any way functional was not your best friend.
If the layers of doped silicon in a chip come lose, the chip stops
working NOW. Semiconductors work because of atom-to-atom contact. Cracks
are fatal and irreparable.

	The printed circuit cards the chips are soldered to can de-laminate,
and that can crack internal layers, but symptoms would be the same as
for any flaky connection- the car would run poorly or die, not accelerate
wildly. And I doubt even Audi is using multi-layer circuit cards for their
engine computers.

	Bill
	A guy who works with VLSI parts for a living.