What Is The Seat Belt Pretensioner

The front passengers of this car have seat belt pretensioners. Although the seat belt pretensioners cannot be seen, they are an integral part of the seat belt assembly. If the threshold conditions for pre-tensioner activation are met, they help to tighten the seat belt during the initial stages of moderate to severe frontal collision, near-frontal collision, or tail collision. And for vehicles equipped with side impact airbags and roof curtain airbags, the seat belt pretensioner can help to tighten the seat belt in a side collision or rollover accident.

The pretensioner only works once. If the pretensioner is activated during a collision, the pretensioner needs to be replaced, and possibly other parts of the seat belt system.