Genuine Daikin 1717969 Solenoid Valve Coil is the electrical coil that opens and closes a solenoid refrigerant valve on command from the control board, switching a refrigerant path on or off. When it fails, the path may not switch correctly and the unit can lose output, heat or cool poorly, or stop and start at odd times. A genuine coil drives the valve the way your Daikin expects, holding reliable switching — where a non-genuine part can drive it weakly or unreliably.