2001 Rodeo ABS Light

The ABS light, on my 2001 Rodeo, intermittently comes on. I have heard that it can be caused by the wiring harness that comes into the truck underneath the driver's seat.
I have checked this and did not see any obvious problems. Is there a way to trouble shoot the wiring and/or sensors without blindly replacing parts?

Does anyone know how to read the codes?
Also, where can I find an explanation of the codes?

Moved to the correct place, you'll get more views here.