Restraints and Safety Systems: Description and Operation

The air bag deploys if the diagnosis sensor unit activates while the ignition switch is in "ON" or "START" position.

The collision modes for which supplemental restraint systems are activated are different among the SRS systems. For example, the driver air bag module and passenger air bag module are activated in a frontal collision but not in a side collision.




SRS configurations which are activated for some collision modes are as shown.




Seat Belt Pre-tensioner with Load Limiter
The seat belt pre-tensioner system with load limiter is installed to both the driver's seat and the front passenger's seat. It operates simultaneously with the SRS air bag system in the event of a frontal collision with an impact exceeding a specified level.

When the frontal collision with an impact exceeding a specified level occurs, seat belt slack resulting from clothing or other factors is immediately taken up by the pre-tensioner. Vehicle passengers are securely restrained.

When passengers in a vehicle are thrown forward in a collision and the restraining force of the seat belt exceeds a specified level, the stopper-A pin will break, allowing the ring gear to rotate. At this point, resistance force from the belt housing is applied to the wire attached to the ring gear so that the wire keeps a constant level of tension (resistance against further rotation of the ring gear in the normal direction). As the ring gear stopper-A rotates and reaches the stopper-B position, it will cease rotation, causing the seat belt webbing to stop extending. By the mechanism, the load limiter permits the specified extension of the seat belt, and a relaxation of the chest-area seat belt web tension while maintaining force.




Built-in Type Side Air Bag
Side air bag is built-in type.

The front seat back with built-in type side air bag has the label shown in the figure at left.