My wife's terrain has just started displaying the warning lights for the stabilitrac and the ABS. whenever she first starts driving the brakes flutter when you press them. they tend to work properly once you drive for a minute but the light never goes out and the problem occurs everytime you start out again. Any suggestions for what this might be? The pads and rotors are brand new. Saw somewhere that it might be the wheel hubs but I don't want to start tearing things apart on a wing and a prayer.