The KSDS (Knock Sensor Detection System) detects vibrations that are signs of immoderate connecting rod bearing wear. This system warns the driver about a previous phase of bearing wear because there may be extreme engine damage and failure.
When constant vibrations caused by bearing wear begin to occur, the MIL (Malfunction Indicator Lamp) will flash continuously to warn the driver of the situation. In addition to this, a DTC code will be set indicating the reason for the problem. In the case of the P1326 OBDII code for Hyundai vehicles, it means that the KSDS has had a malfunction.