Bob

I would like some advice as to how to connect an oscilloscope to an Audi 90
quattro in order to check out the ABS sensor outputs.
I have located the multiple connector under the rear seat and identified the
wires associated with each wheel sensor.

I'm not sure how to connect the oscilloscope leads -

a) into the unplugged connector ?

b) leave the connector in place and connect into the wires before the
connector ?

c) if the connector is left in place, should the ignition be left 'on'
or 'off' ?

d) there are two connectors for each wheel sensor, should the scope lead
and its ground wire be connected across the two connectors ?

Any advice greatly appreciated,

Regards,

Bob

JPF

What are you trying to achieve?

On Sat, 27 Sep 2003 19:54:43 +0000 (UTC), "Bob" <nospam@here.com>
wrote:

> I would like some advice.....................

the rogue

You need to plug the ground of the scope to any grounded part of your
vehicle......turn on the ignition......Jack up the wheel you want to test so
it's off the ground....

Plug the test lead of the scope to any one of the two wires comming from
your abs wheel sensor and then turn the wheel.......one of the two leads
coming from the sensor will give you a higher signal than the other....and
what you should see is a nice square wave that changes frequency with wheel
speed.....

There....that should help!

The Rogue








"Bob" <nospam@here.com> wrote in message
news:bl4pu3$cpi$1@sparta.btinternet.com...
> I would like some advice as to how to connect an oscilloscope to an Audi
90
> quattro in order to check out the ABS sensor outputs.
> I have located the multiple connector under the rear seat and identified
the
> wires associated with each wheel sensor.
>
> I'm not sure how to connect the oscilloscope leads -
>
> a) into the unplugged connector ?
>
> b) leave the connector in place and connect into the wires before the
> connector ?
>
> c) if the connector is left in place, should the ignition be left 'on'
> or 'off' ?
>
> d) there are two connectors for each wheel sensor, should the scope lead
> and its ground wire be connected across the two connectors ?
>
> Any advice greatly appreciated,
>
> Regards,
>
> Bob
>
>

Bob

Thanks,
I'll try this and see if I can find out what is happenning at the wheel
sensor output.
I had been previously connecting the oscilloscope leads across the two
sensor wires...

Thanks for your help.

Regards,
Bob


"the rogue" <therogue@videotron.ca> wrote in message
news:7G7eb.43950$Wk2.1109988@weber.videotron.net.. .
> You need to plug the ground of the scope to any grounded part of your
> vehicle......turn on the ignition......Jack up the wheel you want to test
so
> it's off the ground....
>
> Plug the test lead of the scope to any one of the two wires comming from
> your abs wheel sensor and then turn the wheel.......one of the two leads
> coming from the sensor will give you a higher signal than the other....and
> what you should see is a nice square wave that changes frequency with
wheel
> speed.....
>
> There....that should help!
>
> The Rogue
>
>
>
>
>
>
>
>
> "Bob" <nospam@here.com> wrote in message
> news:bl4pu3$cpi$1@sparta.btinternet.com...
> > I would like some advice as to how to connect an oscilloscope to an Audi
> 90
> > quattro in order to check out the ABS sensor outputs.
> > I have located the multiple connector under the rear seat and identified
> the
> > wires associated with each wheel sensor.
> >
> > I'm not sure how to connect the oscilloscope leads -
> >
> > a) into the unplugged connector ?
> >
> > b) leave the connector in place and connect into the wires before
the
> > connector ?
> >
> > c) if the connector is left in place, should the ignition be left
'on'
> > or 'off' ?
> >
> > d) there are two connectors for each wheel sensor, should the scope
lead
> > and its ground wire be connected across the two connectors ?
> >
> > Any advice greatly appreciated,
> >
> > Regards,
> >
> > Bob
> >
> >
>
>
>
>

JPF

Which is the only way to read the sensors output. Two wires out, A/C
voltage and frequency. Once again, what are you trying to achieve?

On Sun, 5 Oct 2003 21:47:55 +0000 (UTC), "Bob" <nospam@here.com>
wrote:

>Thanks,
>I'll try this...................