Chris Young

Are you using a multi meter or just a circuit tester. the speed sensor will have a resistance in it so might not set off a buzzer. have a look at the resistance level on a multi meter and look for the odd one out. I really would recomend OBD2 reader or Vag Com, will save you a load of time.

Where did you test the sensors? did you unplug it from under the car and test it like that? Sure open circuit means faulty sensor. Checked the fuse? I have just replaced one of my sensors using vag com to check which one was faulty. Took me ages to get the faulty sensor out. But the new one did the trick.