The front seats are equipped with automatic seat belt tensioners to enhance safety.
The tensioners automatically tighten the front seat belts during a moderate-tosevere frontal collision, sometimes even if the collision is not severe enough to inflate the front airbags.

Automatic Seat Belt Tensioners
The seat belt tensioners can only operate once.
If a tensioner is activated, the SRS indicator will come on. Have a dealer replace the tensioner and thoroughly inspect the seat belt system as it may not offer protection in a subsequent crash.
During a moderate-to-severe side impact, the tensioner on that side of the vehicle also activates
Seat Belt Reminder
Fastening a Seat BeltHonda Civic Service Manual. Passenger's Dashboard Trim Panel Removal and Installation (With Navigation)
8411K3
1.
Driver's Dashboard Lower Cover
1.
Remove the driver's dashboard lower cover (A).
2.
Dashboard Subdisplay Visor
...