To ensure the proper functioning and safety of the Seat Belt system, look at the seatbelt and parts. Next, check for the seatbelt indicator on the vehicle's dashboard. As for seatbelt locking, it is common for that to occur when there is a sudden stop or impact. However, it will not lock in place during regular motion. Check the retractors on your seatbelt to make sure it sits firmly against your chest and retracts place into place when not in use. If there are any issues with the parts of the seatbelt, be sure to replace them right away to ensure proper safety for yourself. Regular inspections will ensure the safety of your vehicle and you and your passengers.