Evap. Canister Control Circuit Solenoid. Opens to vent canister of fuel fumes into engine. Check for: broken/cracked vacuum hose leading to solenoid, solenoid coil resistance, resistance to ground. If all good, solenoid plunger may be stuck. Buy new solenoid, not a big cost item. Or ignore CEL, drive with it ON, but doing so masks new codes which if generated could prove real serious.