A bistable solenoid valve device for a fluid system includes a bistable solenoid valve and a detection device. The bistable solenoid valve has a permanent magnet yoke, an armature configured to be displaced between a first armature position for contact against a first core to form an air gap with a second core and a second armature position for contact against the second core to form an air gap with the first core. The bistable solenoid valve device further includes a detection device configured to evaluate and/or measure a first inductance of the first armature coil, and evaluate and/or measure a second inductance of the second armature coil without displacement of the armature, to compare the inductance of the first armature coil and the inductance of the second armature coil, and to output a state signal that indicates the armature position.