[Mk2] [Turbo] how to test speed sensor?

[killerferret666]

I need to test the speed sensor is working correctly on the kitcar, because im not driving it and only on axle stands its not going quick enough to throw up any codes (i've read up above 40mph can throw up codes)

Is there anyway to test the speed sensor?

Also is the speed sensor a standard PPM output, is this a standard format? Reason being im going to a different cluster and obviously want to make sure its compatible.

I'm considering running a wire from the violet wire out of the speed sensor straight to the cluster rather then through the ECU.

Model; Rev 2 Turbo

[Peter Gidden]

Is there anyway to test the speed sensor?

Give it 12V pos and neg and hook signal output to a 'scope.

[killerferret666]

Is there anyway to test the speed sensor?

Give it 12V pos and neg and hook signal output to a 'scope.

Was hoping that wasn't the case, one of the few pieces I don't have is an oscilloscope.

[Peter Gidden]

BTW, it's a 12V square wave. 4 pulses per sensor shaft revolution.

[killerferret666]

BTW, it's a 12V square wave. 4 pulses per sensor shaft revolution.

Thanks, the brown wire from what I read earths to the dial cluster, (May be wrong so earthed seperately.) still didn't work, I'll splice directly into the feed wire tomorrow by passing the ecu, if the digital dials don't pick anything up then I know it's the sensor as I've checked continuity on all wires.

These speed sensors common to go its a rev 2 turbo, presume rev2-5 speed sensors the same.

[Rogue]

I'm considering running a wire from the violet wire out of the speed sensor straight to the cluster rather then through the ECU.

The speedo sensor feeds the instrument binnacle which then processes the signal and supplies the ECU.

[killerferret666]

would of explained why I got nothing....either way

earthing the brown wire and taking the violet wire straight to the cluster solved my problem and I was able to calibrate the speedo easily taking into account wheel size leaving me with an accurate speedo.

[Dame]

Another slightly less scientific method that works for me is to use the continuity tester on a multimeter. If the there is contiunity the meter will beep. Hook the probs up to the sensor wires and rotate the wheel. If your hear the beeping pulse then the sensor should be ok.