Seatbelt Buckle Sensor
WARNING: This page is about a different car, the 2018 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.
The seatbelt buckles contain integrated sensors that are Hall-effect switches. The seatbelt buckle sensors are serviced with the seatbelt buckle.
On vehicles equipped with rear inflatable seatbelts, the buckle at each rear outboard seating position includes the seatbelt buckle sensor. The rear seatbelt buckle is serviced only as an assembly with the sensor.