This is for an Audi tt but I suspect it will be no different. pin 1 blk/wht-12v, pin 2 wht/blu-signal, pin 3 brn-ground. If you dont have the pigtail, take a guess as to which is 1 and which is 3, sensor will be fine. I suspect if you are looking at the sensor connector with the locking tab pointing up, #1 will be on the left.
Testing-pin 1 to 12v, pin 2 to dvom + pin 3 to ground, dvom - to ground. Slowly turn the sensor, watch for high and low voltages. It should be square wave, not sign. You will see the switching points. Count the number of highs, that is your pulses per revolution. If you want pulses per mile, calculate your final drive and the speedo drive, figure out how many times in a mile it will pulse and there you go.
It looks like automatics might use vr sensors so if that doesnt work, connect a dvom to pin 2 and 3 on a lower voltage setting and spin the sensor as fast as you can, see if you get a reading.