Easiest way: Get an oscilloscope, and look at the output of each sensor. That will let you know which one is bad.

http://www.peachparts.com/shopforum/tech-help/288450-trying-troubleshooot-bosch-abs2.html

You could lift the front of the car and spin the wheels. You might be able to simply use an AC volt meter to look for differences, too.

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

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