Freelander System Description and Operation
RESTRAINT SYSTEMS
DESCRIPTION AND OPERATION
75-9
Passenger's Airbag Module Components
1 Trim panel
2 Deployment door section
3 Housing
4 Fixing bracket
5 Tethers
6 Electrical connector
Seat Belt Pretensioners
During a frontal collision the seat belt pretensioners tighten the front seat belts to ensure the occupants are securely
held in their seats. A pretensioner is integrated into the buckle assembly of each front seat belt.
The two pretensioners are handed, but otherwise identical. Each pretensioner has a tube containing propellant and
a piston. The piston is attached to steel cables, the opposite ends of which are 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 airbag DCU.
A fly lead with a 2 pin connector links the igniter to the vehicle wiring.
On receipt of a fire signal from the airbag DCU, the igniter ignites the propellant. The burning propellant rapidly
produces nitrogen gas that drives the piston along the tube, pulling on the cables and drawing the buckle towards the
buckle assembly fixing point on the seat.
Seat Belt Pretensioner Components
1 Seat belt buckle
2 Gaiter
3 Steel cables
4 Fixing
5 Igniter
6 Fly lead
7 Piston tube