Seat Belt Pre-Tensioners
Inertia reel three point seat belts are installed on the front and rear seats. The inertia reels are of the ALR (Automatic Locking Retractor) type. The MRS control unit deploys the pyrotechnic seat belt pre-tensioners at a slightly lower threshold level than the front airbags.
The two pre-tensioners are side specific, but otherwise identical. Each pre-tensioner has a tube containing propellant and a piston. The piston is attached to a steel cable, the opposite end of which is attached to the seat belt buckle. An igniter (squib) in the base of the tube provides an ignition source when triggered by a fire signal from the MRS control unit.
A "pigtail lead" with a 2-pin connector links the igniter to the vehicle's MRS wiring and is located on a bracket underneath the seat frame.