Hyundai is conducting a service campaign to enhance the knock sensor logic with the Cylinder Noise Diagnostic System (CNDS) software update. CNDS is to detect abnormal cylinder wall scuffing or noise of the engine block before potentially severe engine damage occurs. If abnormal noise is detected, the Malfunction Indicator Lamp (MIL) will blink continuously. In addition, DTC P1327 will be recorded in the ECM.
