What's the electrical signal on the VSS wire?

[TobyB]

So I was thinking about logging channels, and realized that logging rear wheel
speed's as easy as capturing the VSS sensor... if I knew what, exactly,
what that signal was!

Is it anything more complicated than a tach signal from the rear end sensor?

(which is, what, 8 blades or so, so 8 pulses per wheel rev?)

Thanks!

Toby

[nando]

it's a 9-tooth wheel. get the signal from the back of the cluster (where the cruise control plugs in), not straight off the VSS sensor. the sensor itself doesn't output a good enough signal to be useful.

a 0-5v switched input should work. you could also tap into the black/white wire of the C101.

[TobyB]

Righty- o, so VSS (the signal from the cluster)'s just a conditioned 9 pulse- per- rev signal?

Sounds pretty straightforward.

Thanks!

t

[nando]

yep! all you need to know is the size of your tire and you can calculate the pulses per mile/km.