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, to ...

ON
This is the normal operating position after the engine is started. ...

Unfastening the front seatbelt
Push the button on the buckle. Before closing the door, make sure that the belts are retracted properly to avoid catching the belt webbing in the door. ...