Impala V8-5.3L VIN C (2006)
Seat Belt Tensioner: Description and Operation
INFLATABLE RESTRAINT SEAT BELT RETRACTOR PRETENSIONER
The seat belt retractor pretensioner modules contain a housing, a seat belt retractor, the seat belt webbing, an initiating device, and a canister of gas
generating material. The initiator is part of the seat belt pretensioner deployment loop. When the vehicle is involved in a collision of sufficient force, the
inflatable restraint sensing and diagnostic module (SDM) will cause current to flow through the deployment loops to the initiator. Current passing
through the initiator ignites the material in the canister producing a rapid generation of gas and the release of compressed gas, if present. The gas
produced from this reaction deploys the seat belt pretensioner and retracts the seat belt webbing, which removes slack in the seat belt.
Depending on the severity of the collision, the seat belt retractor pretensioner may deploy without the frontal inflator modules deploying, or they will
deploy immediately before the frontal inflator modules deploy. As soon as three distinct deployment commands (representing different events) have been
issued to any belt pretensioner the SDM shall be considered to not be reusable.
Each seat belt retractor pretensioner is equipped with a shorting bar located on the connector of the pretensioner. The shorting bar shorts the seat belt
pretensioner deployment loop circuitry to prevent unwanted deployment of the pretensioner when servicing the seat belt pretensioner.
