Fuel cell system

A fuel cell system, comprising:

• a fuel cell;
• a hydrogen gas supply passage configured to supply hydrogen gas to the fuel cell;
• a solenoid valve configured to change an opening degree of the hydrogen gas supply passage;
• a pressure sensor configured to detect a pressure in a downstream supply passage which is a part of the hydrogen gas supply passage from the solenoid valve to the fuel cell;
• and
• a control circuit configured to control the solenoid valve,
• wherein
• the control circuit is configured to perform:
• detecting and storing a conducted electric current conducted in the solenoid valve and the pressure at plural points while changing the conducted electric current at a first sweep speed;
• detecting and storing the conducted electric current and the pressure at plural points while changing the conducted electric current at a second sweep speed different from the first speed;
• and
• controlling the solenoid valve based on the stored electric currents and pressures.