ABS wheel speed sensor failure

[Wh33lhop]

So I just grabbed 3 seemingly great condition wheel speed sensors from the yard and so far, combined with the 4 bad ones that came with my car, out of seven sensors I have a single good one. They all ohm out between 1020 and 1070 ohms. What exactly goes bad on these things, and are most of them bad at this point? Seems ridiculous to spend the $400 to get 4 new ones; if they are all dead though maybe it should be done.

And no, I don't want to delete ABS.

[e30vert]

This is a stupid question , but if they all ohm out at nearly the same reading then how have you diagnosed that they are non functional? Dont have any for you to sell or give away , but want to expand my knowledge of ABS sensors.

[Wh33lhop]

The ABS light will come on as you begin driving the car, if the wheel speed sensors don't agree with each other. So, you can unplug all but one sensor and drive the car in order to check if the sensor is operating. If that one sensor is sending a signal, then it will disagree with the rest that are sending nothing, and the ABS light will activate. If it's bad and not ending a signal, then the ABS light won't come on because they will all be sending a zero speed signal.

[Wh33lhop]

Update: found some wheel speed sensors and fixed it. The above procedure works, BUT ONLY FOR THE FRONT WHEELS. spin the rear wheels forward while the fronts are stationary and the ABS computer just thinks you're being a hooligan smoking the tires, so no light thrown. That means if you unplug all but the rear sensors, the light should not be thrown whether or not the rear sensors work.