Genuine Fujitsu 9900197025 Outdoor Expansion Valve Coil is the expansion valve coil in the outdoor unit, the motor that opens and closes the valve to meter refrigerant flow as the board asks. A failed coil leaves the valve stuck, so the system loses that control and heats or cools poorly or stops with a fault. The genuine part is the one Fujitsu built this outdoor unit around, so it goes back in as the original did.