On Fri, 2007-06-29 at 04:18 +0000, McReynolds, Alan A wrote:
> The "electronic throttle modules", actually pedal position sensors, are
> rarely, if ever, a simple rheostat.  The Bosch variety uses two Hall
> effect sensors mounted 180 degrees to each other.  These are in turn
> subjected to a field that rotates as the shaft is rotated.  This way a
> signal and anti-signal is produced.  Only if they match correctly does
> the ECU operate on the signal.  A simple rheostat would kill a lot of
> folks.

Cool! Makes sense.

For cars that do have a throttle cable, but have electronic fuel
injection and ignition, the sensor is often (in my experience) a
rheostat. Of course in those cars it isn't as important a safety issue
if the computer thinks you're flooring it when you're not since it's the
cable moving the throttle plate, all the computer is doing with the info
is adjusting timing.

Very interesting info on the throttle by wire, thanks for that!

TTYL

PS. My latest car has throttle by wire and I actually don't mind it.
Other cars I've driven with throttle by wire had a "lag" when you hit
the gas that was most annoying, this car doesn't have that lag. OTOH, it
is kinda annoying being under the hood with the engine running and being
unable to "rev" the engine up by pushing the throttle cable
connection! :)

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