Four Button Diagnosis
The OnStar control unit will perform a four button diagnosis. When an open or short to ground failure has been found at the button input line, the OnStar control unit will store the DTC and turn the red LED ON.
The OnStar control unit will perform a four button diagnosis. When an open or short to ground failure has been found at the button input line, the OnStar control unit will store the DTC and turn the red LED ON.