On Mar 4, 12:23*am, wrote:
On Wed, 3 Mar 2010 07:49:16 -0800 (PST), wrote:
On Mar 3, 10:06*am, dpb wrote:
wrote:

...

Yes, but you missed my whole point. * You acknowledged that it's
desirable to have some kind of interlock to keep the car from being
shifted into at least Park while it's moving. * OK, so I implement
that system via an interlock system consisting of a solenoid driven by
the computer. * That's right, the same computer that is malfunctioning
and has the throttle pegged. * ...

Automotives don't use simply a single computer -- hence there is no "the
computer". *There are a multitude of very small (and some not so small)
microprocessors. *The likelihood of there being multiple systems on the
same processor is small.

Nonsense. *Sure there are multiple computers in a car. *Common ones
are for the engine control, ABS, climate control, etc. * But nothing
says that one computer cannot be responsible for many systems. *Why
would it seem unusual to have a case where the engine start/shutoff
was in the same computer as that which determines the throttle
position? *It is part of the engine control, is it not? * *And if
there was an electronic shift interlock, why would it be unusual for
that same computer to control it? * That computer is the one that
knows if the car is running, what speed it's traveling at etc.

I don't know what exactly any of the computers in these cars controls
or how the system is put together. * Yet, you among others, are
jumping to conclusions on what is possible or impossible without any
facts.

And in FACT, on most current production vehicles, there is either one
or 2 computers that control everything. Common practice seams to be a
PCM (Powertrain control module) and a BCM (Body control module).
The PCM handles *engine and transmission and all related functions -
often including cruise control, stability control, ABS, etc, while the
BCM handles the AC, power windows, sometimes cruise control etc, and
the instrument panel, among others.

SOME vehicles use only one computer to handle everything (including,
apparently, the RADIO.


And your source for that would be? Everything I've seen over the
years is that there are more and more microprocessors, ie computers in
cars. And that only makes sense as cars become increasingly
complex. Do you really believe the radio, CD player, GPS, etc are all
controlled by one computer and that it makes sense to do that, when
you can have a cheap local microcontroller that tends to functions
right where they need to be handled, eg radio, gps, climate
control.

Here's a news story that says you are wrong:

http://news.bbc.co.uk/2/hi/8510228.stm

They identify at least 8 computers in a typical car. A computer
doesn't have to be a big module. It can be as simple as an 8 bit
microcontroller that sells for $1 and is used to run something like a
dashboard display or the radio. You can't even buy it or replace it
as a seperate part any more than you could with the one in your
dishwasher, microwave oven, etc.