Could be a bad sensor. The only real way is to check the signal with a scope; the resistance test only locates "obviously" bad sensors.

Still, you should ohm the rear one before tracing a bunch of wiring. If it's "good", then you should test the inputs for wire continuity at the controller from the sensors. If the wires are good, it's either your controller or one of the sensors...

How does it brake?

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A.S.E Tech A1,A6,A7,A8 & MVAC 609 + EPA 608

Unless stated otherwise, any question I ask is about my greymarket 1985 380SEL.