An airbag jacket activating system includes radio communications transceivers configured to make RF communications and LF communications, respectively. An acceleration sensor configured to detect acceleration of a motorcycle. An update unit configured to update an LF communications ID, to code the updated LF communications ID together with an RF communications ID, and to transmit the coded updated LF communications ID and the coded RF communications ID to an airbag jacket through RF communications. An update unit configured to store the updated LF communications ID in a case where the LF communications ID is received together with the RF communication ID. A control unit configured to cause the coded RF communications ID and an ignition signal to be transmitted through the RF communications, and to cause the LF communications ID and the ignition signal to be transmitted through the LF communications when the acceleration exceeds a predetermined value.