Restraints and Safety Systems: Description and Operation

SEAT BELT TENSIONER
The seat belt system incorporates Seat Belt Tensioners. The tensioner is designed to hold the occupant in their respective seat by retracting the seat belt up to four inches. They are integral to the front seat belt buckles and cannot be serviced. If found defective they must be replaced. After an airbag deployment, the tensioner must be replaced.

At the onset of an impact event, each tensioner uses a pyrotechnic device which is triggered simultaneously with the airbags to rapidly retract the seat belts. With the slack removed, the occupant's forward motion in an impact will be reduced as will the likelihood of contacting interior components. After an impact that deploys the airbags, the seat belt tensioner assembly must be replaced.

The Occupant Restraint Controller (ORC) monitors the seat belt tensioner circuit resistance and reports active and stored Diagnostic Trouble Codes (DTC's) if any problem is found.

Once a vehicle has been in an accident, the tensioner must be replaced along with any deployed airbags and broken or damaged parts. Refer to the proper Body Diagnostic Procedures for diagnosis and testing.

WARNING: WHEN THE FRONT AIRBAG IS DEPLOYED, THE TENSIONER WILL HAVE DEPLOYED ALSO AND SHOULD BE REPLACED.