2003 Ford Focus RS - sensors question ?

[stevieturbo]

I don't think you can view the raw data from slaves in the same way as direct inputs.

Slave driven speed on mine from the expander is unreliable compared to a when they were a direct connection
Which was annoying

[Jackstrath]

Aww well, guess I’m moving some pins around

[Jackstrath]

So been doing a bit more wiring and moving things about.

Iv now decided to tap into the abs wires to get the signal from them for wheel speed. Iv moved left and right signal to an03/04 respectively.

But I can not seem to get a signal from them. I was told to wire into the “signal side not the ground” so that’s what I think I have done but all I see is 5v when I set the gauge up on scal?

Just for info Iv tied into both the white 45 pin and white red 34 pin which when I did my checks prior to wiring these are the signal wires as the browns went to earth?

Set the sensor type to 5v bipolar but still nothing showing?

[stevieturbo]

No idea what sensors are fitted to your car.

Scope them and see. And I'd be surprised if the abs unit will be happy with you tagging into the wires.

What does the raw input look like on a graph trace at 1000hz ? Or logged at same?

[stevieturbo]

If 2 wire as the drawing seems to say, they could be vr or the more awkward resistive sensors.

Their x4 expander seems to say it can hook up to and sensors.
Whether that expander can be used in conjunction with other expanders, I don't know.

But scope the sensors

[Jackstrath]

They are MR sensors, so I know they will be polarity sensitive.

That’s a thing I think I set the gauge to 1htz so that could be why I didn’t see anything on the gauge! Doh!

I don’t have a scope sadly not sure my multi meter will do the job. Il have a play and see.

[stevieturbo]

If they are mr, not sure the syvecs will be able to use them directly ?

X4 specifically mentions MR sensors.

[Jackstrath]

So had another poke about there.

So the abs system works on 12v’s it would appear…. An03 and an04 only show 5v……

Turn the wheel with my multi meter in and you’ll see the voltage fluctuate….. just can’t get that onto the syvecs

[stevieturbo]

MR sensors have a constant voltage and work off current variations.

As already said, the X4 manual makes specific reference for MR sensors.

Not sure what other option there might be, unless you can point another sensor at the tone wheel ?

Does the DSG need all 4 wheel speeds ? Or what exactly does it need ?

[Jackstrath]

Yeh i think you might be right with regards to what other options are left!

The DSG soft wear requires a stable, but high resolution signal for wheel speed.

I was using the 12 brake bell bolts as a reference with my own hall effect sensor but was getting some errors on the box which was causing it to lock into neutral.

The soft wear only needs to see left and right driven wheel speed to work. So two minimum inputs. Doesn't let you use GPS or anything as a speed input...

Iv attached a photo of my brake bell speedo sensor that i had on each side of the car. Like i said for the most part worked but still chucked a transmission error....


So i guess my only question is if i do go down the X4 route, i see its to be pin'd to CAN2, I have my Dash on that? Can you run 2 things on one CAN?
If not and i need to move the dash or the expander to CAN3, That currently has my EGT going into it? Could that move onto the expander?