ABS light came on - codes said it was right front sensor. Sensor voltage is low, about 1/4 of normal according to my mechanic.

Questions are these:

1. What causes low voltage? Dirty sensor, nicked wire, or other cause?
2. Can a dirty sensor be cleaned easily?
3. If sensor is defective, how much does it cost, and how hard is it to replace? I am competent at basic repairs (brakes, tune-up, etc.) but I have my limits when it gets more in depth.

1997, S-10, 4x4, 4.3 l, 180,000 miles!

Thanks guys!

 

Low voltage is typically caused by an increased air gap between the sensor and the reluctor ring. On the newer style hubs which have the WSS bolted to them, you would tighten up the air gap by filing down the surface that the sensor mounts into. The voltage needs to be >350mV-AC.

The sensor can be cleaned. Just have to remove it which may require the removal of your front hub if you have the old style sensor that is in the brake backing plate.

You can look up the wheel speed sensor costs via your favorite autoparts store webpage. Depending on which style you have, the job can be quite easy to a bit on the difficult side.