Prenotification information of releasing prohibition of an engine operation is stored in an EEPROM in an interval. The interval is after that a lock controller commands a steering lock to be operable. The interval is before that an engine controller switches an engine operation prohibiting signal to be in a prohibition releasing condition. The engine operation prohibiting signal may change from the prohibition releasing condition to the prohibition setting condition after an engine starting controller starts an engine. In this condition, the engine is stopped, or is continuously operated in accordance with the prenotifying information stored in the EEPROM.