Air Bag Supplemental Restraint System (SRS): PRETENSIONERS
WARNING: This page is about a different car, the 2011 Jaguar XKR, 2011 Jaguar XK, 2010 Jaguar XKR, and 2010 Jaguar XK. However, it is still accessible from the selected car via links, so may be relevant.
| Item Number | Description |
|---|---|
| 1 | Electrical connector |
| 2 | Pyrotechnic pretensioner |
| 3 | Safety belt buckle |
The pretensioners are used to tighten the front safety belts during a collision to ensure the occupants are securely held in their seats. A pretensioner is integrated into each front safety belt buckle.
Each pretensioner has a tube containing an inflator and a piston. The inflator is connected to the restraints control module (RCM). The piston is attached to a steel cable, the opposite end of which is attached to the safety belt buckle.
On receipt of a fire signal from the restraints control module (RCM), the inflator generates nitrogen gas that rapidly expands to drive the piston along the tube, pulling the cable and drawing the safety belt buckle downwards.