It's my understanding, and this is from a write-up in a magazine a while
back, that GM's ABS is not electronic, but mechanical. There is a
differential pressure maintained during braking by wheel rotation.
Somehow this is released if the wheel stops, and a valve opens and
bleeds pressure off the piston. When the wheel starts rolling, the
differential reapplies and braking resumes. There is no wheel speed
sensor, no computer, no hydraulic servos. It's cheap, and by the letter
of the definition, it is ABS, but it's very slow in response compared to
electronic systems, easily demonstrated by driving just about anyone
else's ABS-equipped car. It's cheap enough, though, to put on everything
they make, which GM thinks is a marketing bonanza.
Walter Fooshee
Dixie Region Probe GT
"D. Barry Stubbs" wrote:
> Another example of what happens when we
> let something electronic take over something that a human could've
> done perfectly well... <sigh>.
>
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