'94 speedometer reading higher speed
 

Been checking around and figured I'd ask...


My '94 V6 LE automatic 4-wheel disc with ABS has been giving me a wrong speedometer reading for the past year and a half. Blew it off as one of those little quirks I can drive with as I've got the ratio down to somewhat know my actual speed. It first started out as sometimes wrong speed then back to normal and now just wrong all the time. It shows a higher speed than actual. 25mph reads 30mph, 50mph reads 58mph, 75mph reads 90mph...


There are four speed sensors, one at each wheel. I'd replaced the driver front wheel speed sensor with a factory/dealer part just before the whole problem began. Any troubleshooting techniques to try with these speed sensors or is there another module that I need to inspect?

Speed sensor is on trans, not wheels.

Maybe I'm confusing the wheel speed sensor at each wheel for the ABS system. I'll check the tranny sensor this weekend. Any diagnostics to do or just go and replace it?