See also:

Operation
If the driver and/or front passenger have/ has not yet fastened the seatbelt(s) when the ignition switch is turned to the “ON” position, the seatbelt warning light(s) will flash for 6 seconds, ...

Specifications
These specifications are subject to change without notice. ...

Seatbelt warning light and chime
NOTE If your seatbelt warning device does not operate as described in the following, it may be out of order. Have the device inspected and, if necessary, repaired by the nearest SUBARU dealer. Y ...