Rainier AWD L6-4.2L VIN S (2005)
Seat Belt Tensioner: Description and Operation
Seat Belt Pretensioner
SEAT BELT PRETENSIONER
The seat belt pretensioner consist of a housing, a seat belt retractor, the seat belt webbing, an initiator, and a canister of gas generating materials. The
initiator is part of the seat belt pretensioner deployment loop. When the vehicle is involved in a collision of sufficient force, the sensing and diagnostic
module (SDM) causes current to flow through the seat belt deployment loops to the initiator. Current passing through the initiator ignites the material in
the canister producing a rapid generation of gas. The gas produced from this reaction deploys the seat belt pretensioner and retracts the seat belt
webbing, which removes all of the slack in the seat belts. Depending on the severity of the collision, the seat belt pretensioner may deploy without the
frontal inflator modules deploying, or they will deploy immediately before the frontal inflator modules deploy. The seat belt pretensioner will deploy
immediately before the frontal inflator modules deploy. Each seat belt pretensioner is equipped with a shorting bar that is located in the connector of the
seat belt pretensioner. The shorting bar shorts the seat belt pretensioner circuitry to prevent unwanted deployment of the seat belt pretensioner when the
connector is disconnected.
