[BNaylor]

You can't tell if a wheel sensor is bad by listening to mechanical hub noise. Many times there is no correlation between the two. It needs to be scanned with an ABS capable scan tool like a GM Tech II. The wheel sensors are temperature sensitive to include the EBTCM module.

Also, you can check wheel sensor resistance with a DMM. They will read around 1K ohms. Just pull the electrical connector at the backside of the hub and go across the two contacts hub side.