The noise can be anything from worn out brakes that are grinding to the normal sound of the anti-lock system activating, but when it's not called for. Given that GM has had a real big problem with their front wheel bearings causing false ABS activation, those are the likely suspects. The wheel speed sensors develop real wimpy signals to start with, then the normal play that occurs in the wheel bearings causes even weaker signals to be generated until the point when the computer can't see them. At that point it thinks that wheel stopped rotating and it needs to try to stop it from skidding.
Electrically the speed sensors are still okay so no diagnostic fault code may be set related to that, but since the yellow warning light is on, there will be some other fault code in that computer. You'll need to find a mechanic with a scanner that can access that computer to see what the fault code says. It will indicate the circuit or system that needs further diagnosis, or the unacceptable operating condition.
Wednesday, September 3rd, 2014 AT 5:28 PM