Test the plug for voltage with a meter. With the key on you should see 4.8V or so. If not, then your wire is bad somewhere else down the line. Just went through this on my 00 GT. If the harness checks out then meter the 2 leads in the wheel bearing. Jack that side up and put it in neutral, chock the rear tires. Set meter to millivolts. At rest you should get 0, and then have someone spin the tire. You should see some voltage show up on the meter. If this does nothing then you have a bad hub and will have to replace it.
Also, check all your fuses and make sure none are blown. Should be the underhood and inside the car. Worst case save up some $$ and have it scanned at a dealer or shop that can read the ABS codes, as the scanners at most parts stores will not read these cars. Need a GM Tech II usually. That will tell you exactly which wheel is having an issue. Post the code here and we can help further.
