Seat Belt Pre-Tensioners
Inertia reel three point seat belts are installed on the front seats. The inertia reels are of the ALR (Automatic Locking Retractor) type. The MRS control unit at a slightly lower threshold level than the front airbags activates the front seat belt pre-tensioners.
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 fly 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.