Speed Sensor/Abs light/ Speedometer

[E-rock]

my abs light has been on for several months and ive noticed rapid wear to the front brake pads. ive read almost every post on this forum related to the abs sensors and problems, which has mostly answered my question. My speedometer is about 8 mph off in the wrong direction. when the speedometer says im doing 55, im really only doing 47 or 48 mph. after i put 31 inch tires (replacing the stock 29's) i figured that the car will not know to adjust so i did a little bit of math and the wheel speed should be up 3mph. so when the speedometer says im doing 55, now i should actually be doing about 50-51 mph. my question is: is the reason for the illuminated abs light and speedo whacked out caused by the speed sensor in the differential? or is it two different problems? i dont have enough money to have a dealership diagnose and i am new to the area in tampa, florida. i dont trust any mechanics down here to work on my truck as much as i trust myself. ive been doing all my own maintenence since i was 15, and i can do almost anything except for engine/transmission work. is there a way to turn off the abs light without using a code reader? i have a 2001 explorer xls with auto-4wd btw. thanks to anyone that can help.
-erik

 

[rwenzing]

The speedometer in your 2001 Ex 4-door is driven by the rear axle ABS sensor so the problems are likely related. The sensor is probably what's wrong but without the ABS trouble code, you're just guessing.

 

[E-rock]

thats true but im trying to make the most educated guess possible. all of the drive-speed information is electronic, so if i replace the speed sensor will the speedometer read the stock speed again or will it have to be recalibrated?