"I brought it in to have the ABS sensor troubleshot. The scanner was only able to read 1 wheel speed sensor."
Was this a local garage or GM garage?
What were the codes?
So you are saying that, when they put the scan tool on, they could not read data from three of the wheels? But they could from one?
Most shops have a spare hub that they can attach to the harness connector....they spin the hub and look for data....this verifies if the hub sensor is bad, or if it is a harness problem.......