939004683 - E7030 AIR BAG - DESCRIPTION

DESCRIPTION

The vehicle is equipped with an electronic control system that governs the acivation of specific containment devices in the event of frontal or side impact.The frontal protection system includes:- driver and passenger front air bags with two-stage activation;- single-stage driver''s knee bag, single-stage passenger''s knee bag (option);- front airbags with pretensioner on buckle and degressive load limiter;- direct mesh rear seat belts (without idler ring) and strap buckle branches- decentralised supplementary front impact detection sensor;- passenger air bag manual disabling switch.The side protection system comprises:- two sidebags under the fabric on the front seats;- two drop-down headbags housed in the under-roof rails;- two impact detection sensors located in the central pillar.The front protection system features new Air Bag Smart 2 activation software that automatically adapts activation parameters according to impact severity.Driver and passenger front airbags feature two-stage activation:- when the impact is of moderate severity, the electronic control unit controls the first airbag activation stage and then, following a significant temperature increase, the second stage so that the energy discharged onto the occupant is not harmful.- for very severe impacts, the control unit activates the second stage after a small temperature rise, i.e. almost immediately, so that as much of the occupant''s kinetic energy as possible can be absorbed before he or she strikes the steering wheel or dashboard.A supplementary ECS “Early Crash Sensor” on the front beam near the bonnet lock also helps the electronic control unit to operate more quickly than a conventional system so that the airbag activation stage is comleted before the occupant''s body begins to move towards the steering wheel or dashboard.The control unit is located under the centre console and is securely fastened to the bodyshell: in this way the deceleration sensors located inside the unit are near the centre of gravity and detect the deceleration for the entire vehicle accurately.There are two stages for the front Air Bag modules: the first intervenes at an intial impact level, the second in the case of a more serious impact.The driver side air bag module is located in the middle of the steering wheel. It is fitted on a tilting plate that is also used to control the horns. The plate houses a metal container that contains the folded bag and the gas generation device that inflates the bag.A clock spring allows the connecting cables for the Air Bag module to follow the rotation of the steering wheel without danger of breaking.The passenger Air Bag is located on the dashboard, and is fastened directly to the vehicle crossmember by means of a special bracket.The passenger air bag may be deactivated manually by means of a special switch which can be operated using the emergency key: it is located to the right of the dashboard, passenger side.In the OFF position the control unit also controls activation of a special "passenger air bag disabled" warning light.The "knee" air bag modules are also fitted in the lower part of the dashboard in front of the passenger''s knees and beneath the driver''s steering wheel. These single stage modules protect the lower limbs and increase protection for the driver and front passenger, particularly by preventing them from sliding forward, which is a possible cause of injury, particularly to the chest.The side bag protects the chest area and also - together with the door panels - protects critical areas of the body such as the ribs and abdomen. Its position on the seat always ensures maximum efficacy irrespective of seat position, even if the seat occupant is not seated correctly, because bag opening dynamics minimise the risk of body damage due to impact against the body.The window bags are activated together with the sidebags and interpose themselvers between the occupant and the vehicle to prevent the head coming into contact with highly intrusive objects such as glass, pillars etc.Because the window bags extend from the front pillar to the luggage compartment, they protect front and rear passengers. The window bag system offers the best performance due to the broad area covered and their ability to be self-supporting even without a backing.The pretensionsers are located on the front seat belt buckle. Activation of the seat belt pretensioners is controlled by the same strategy as the air bags.The pretensioners are designed to take up slack in the seat belt to ensure it holds the occupant against the backrest from the first moments of impact, thus reducing movement inside the passenger compartment.The control unit is equipped with an autodiagnostic function:- it detects and stores faults;- it recognises the various components and the fault type;- it indicates the onset of faults by means of the special warning light.The activation of the system following a particularly serious impact is memorized by the control unit.When the system autodiagnostic function detects a fault or an impact is recorded, the control unit sends a signal, via the CAN, for the Air Bag fault warning light located in the instrument panel.Similarly, it lights up the passenger Air Bag disabled warning light and the seat belts not fastened warning light: this warning light signals that the driver''s seat belt is not fastened, coming on constantly from the key on; the warning light in the panel starts to flash and the instrument panel buzzer sounds intermittently if the vehicle speed exceeds 25 km/h or more than 500 m is travelled.
The latter warning light uses information from the two switches in the front seat belt buckle and a passenger presence sensor under the cushion: this information does NOT affect the Air Bag activating logic.
For more details    See descriptions 5580C AIR BAG SYSTEM The system control unit supply lines are protected by a specific fuse in the junction unit under the dashboard.
When operations are carried out to the Air Bag system, the following safety recommendations must be closely followed. For more details    Op. 5580C AIR BAG SYSTEM