2003 Explorer ABS Light on

Does anybody know why this light is on?

It means that there is some fault with the ABS system. There should be a code stored.

brakes seem fine but i do notice that the back rotors are worn down pretty good. Have been told it could be a bad rear sensor but I am not sure where it is.

x2 on getting the code read. there are about 14 sensors, most common failure are the Master Cyl switch (if you have one), rear ABS sensor and fronts bearings are next, ABS module . . . There are some good post on this too. Codes will be the sure method of finding out what wrong.

This was my new year's headache for like a month...
Check out my thread after the codes are read, in case you get the same I did...maybe a Midas or a friend that has a scan tool with ABS readout compatibility...

http://www.explorerforum.com/forums/showthread.php?t=235081

Got underneath to find ABS sensor and see that my rear differential is leaking, looks like it is a bad seal. Pulled plug to make sure I had some fluid left and some metal shavings came out. Am taking it in to the shop to have ABS sensor checked out and I was wondering if the metal shavings could possibly have something to do with the ABS light on. Also am I in big trouble with the metal shavings being present or do I just need to put new fluid in? Not hearing any sounds or anything while driving. I had my rear differential repaired about 2 years ago.

The magnet in the ABS sensor will attract metal shavings, and throw an ABS light. How much metal did you find? Was there any fluid in there or just metal shavings?

pulled the plug and fluid came out, we were on an even surface. There was plenty of fluid, it looks like it was overfilled and there was some metal shavings in the fluid that came out, but not big chunks. It was fine metal shavings. We didn't open it up to take a look, just put plug back in.