Pyrotechnical Seat Belt Tensioner

Pyrotechnical seat belt tensioner




The driver and front seat passenger seat belts are each equipped with a pyrotechnical seat belt tensioner.
These seat belt tensioners have a gas generator with an electrical igniter (C) connected to a cylinder. In cylinder (D) is a piston with a wire, one end of which is wound around a drum connected to the belt reel.
An electrical signal from the sensor module activates the gas generator and the gas produced drives down the piston in the cylinder. The cable is tightened and rotates the seat belt reel, taking up any slack in the seat belt. The tensioner can take up a maximum of 9 cm (3.5") of slack.

Warning! Seat belt tensioners must never be disassembled, repaired or transferred to another vehicle.

If the car is to be scrapped or the seat belt tensioners removed, see Handling non-deployed airbag modules/pyrotechnic seat-belt tensioners Handling Non-Deployed Airbag Modules/Pyrotechnic Seat-Belt Tensioners.

Note! Volvo recommends that seat belt tensioners be replaced every 10 years to maintain reliability.