Sounds like you may have trashed a speed sensor and that will NOT come up on most ECU scans. I tore my right rear sensor wire in Moab last year and I have the light on and no rear ABS - no code with several scanners. Have you tested to see if you the front ABS is working by stopping hard in a parking lot?

To reset the computer so you don't loose your presets or clock, remove the cover below the cd changer and unplug the three large connectors to the ECU for a few minutes.