I've had my ABS go out a few times in the past and always fixed it by either replacing one of the relays (could hear the pump stuck on), or by cleaning the wheel sensors.

However, this time none of the usual tricks work. The light does not come on until you get the car moving at least 5-10mph, just creeping does not trigger the light. I figured this was an obvious bad sensor but the cleaning didn't help. Resistance checks for all 4 sensors were good, as were most of the other system checks in the manual. The only odd thing I could find was while measuring AC voltage from the sensors while spinning a wheel manually. Trying to spin about 1rev/sec, three of the sensors would read about .3-.4V, and the right rear would read more like .7-.8V. This behavior is very consistent.

I have some new sensors on the way, just curious if it makes sense to anyone else that the one sensor it bad? If the AC amplitude is proportional to speed it would make sense, but I couldn't really check over higher speeds.

-Andy M.