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. Dashboard/Steering Hanger Beam Removal and Installation (Natural Gas models)
8411J6
1.
Battery Terminal (SRS) - Disconnection
1.
Make sure the ignition switch is in LOCK (0).
2.
Disconnect and isolate the negative cab ...