A fuel system is provided, including a fuel tank isolation valve comprising an actuation coil and a latchable valve shaft at least partially disposed within the actuation coil. A controller may be configured to indicate a position of the valve shaft based on a measured current-voltage relationship between the first and second terminal wires during a condition in which the magnetic field generated by actuation coil current has a flux density below a threshold required to adjust a position of the latchable valve shaft. In this way, the position of the latchable valve shaft may be indicated without moving the valve shaft, and without requiring a dedicated valve position sensor.