Depending on the fault code meaning, the service personnel remove the right B-pillar trim board and prepare to check the tensioning line. However, after removal, it was found that the seat belt tightener looks good, the seat belt tightener plug-in and wiring are not a problem. The car seat belt for the double pretension structure, the bottom also has a tensioning device, with the upper tensioning device together to shrink, to protect the occupants of the car. The service personnel then remove the floor and focus on checking the floor harness connection for false or damaged.