Checking Seat Belt Tensioner Piston Position

Fig 1: Identifying Piston Positions

Courtesy of VOLVO CARS OF NORTH AMERICA.

Insert a wire in the pipe on the seat belt tensioner as illustrated.

Check seat belt tensioner piston position.

Piston in position A: 

• The seat belt tensioner has deployed. Replace both seat belt (inertia) reels with seat belt tensioner.

Piston in position B: 

• The seat belt tensioner has not deployed.