DESCRIPTION
The vehicle is equipped with an electronic control system that governs the activation of specific containment devices in the event of frontal or side impact.
The comprehensive version of the system includes the following for frontal protection:
- driver and passenger front airbags with two-stage activation;
- single-stage driver's knee bag;
- front seat belts with dual pretensioner and load limiter;
- rear seat belts with load limiter;
The most comprehensive version of the side protection system comprises:
- two side bags on the front seats;
- two window bags housed in the under-roof side members;
- two impact detection sensors located in the central pillar.
The front protection system features new Airbag Smart 2 activation logic that automatically adapts activation parameters according to impact severity.
The driver and passenger front airbags feature dual-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.
The control unit is located under the centre console and is securely fastened to the body: 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 two front airbag modules: the first intervenes at an initial impact level, the second in the event of a more serious impact.
The driver's airbag module is located in the middle of the steering wheel. It is fitted on a rocker 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 airbag module to follow the rotation of the steering wheel without danger of breaking.
The passenger airbag is located on the dashboard, and is fastened directly to the vehicle crossmember by means of a special bracket.
The driver's knee bag module is located in the lower part of the dashboard, beneath the steering wheel. This single-stage activation module, in addition to protecting the lower limbs, increases protection for the driver, 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 side bags and place themselves 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 pretensioners are located on the front seat belt retractors. Activation of the seat belt pretensioners is controlled by the same strategy as the airbags.
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.
This vehicle also features a second electronically controlled, pyrotechnic type pretensioner, which acts on the seat belt mounting third point, drastically reducing the forward movement of the pelvis and legs and, therefore the violence of the impact of the shins and knees against the lower part of the dashboard.
In addition, the combined action of the two pretensioners, working at different points, almost totally eliminates slackness of the seat belt, keeping the effect of the occupant slipping under the seat, known as the submarining effect, to a minimum.
The control unit is equipped with a self-diagnostic 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 memorised by the control unit.
When the system's self-diagnosis function detects a fault or an impact is recorded, the control unit sends a signal, via the CAN, for the "airbag failure" warning light located on the instrument panel.
Similarly, it lights up the "passenger airbag disabled" warning light and the "seat belts not fastened" warning light - SBR function:
The Seat Belt Reminder comprises a buzzer which switches on the warning light in the instrument panel and flashes, warning the driver and the front passenger that their seat belt is not fastened
On some versions there is also a trim, located above the interior rear view mirror, that, through visual and acoustic signalling, warns all the passengers, even those in the rear seats, that their seat belt is not fastened. The red and green warning lights work as follows: - off if the ignition is in the MAR-ON position and the seat belts are already fastened - red if the front seat belts are not fastened - red flashing (for the rear seats only) if the front seat belts are not fastened - green if seat belts are fastened. The two side warning lights relate to the front seats, whilst the three middle warning lights relate to the rear passengers.
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The information for the five switches located on the seat belt buckles and the passenger presence sensor are used for the SBR function and do NOT in any way affect the airbag activation logic. |
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If it is absolutely vital to transport a baby in the front seat, the front passenger airbag and the relevant side bag can be deactivated as well as the front passenger seat belt pretensioner. The passenger airbag disabling function is activated via the setup menu in the instrument panel, not using the key! When it is deactivated the warning light in the instrument panel comes on. |
For more details
See descriptions 5580C AIR BAG SYSTEM
The system control unit supply lines are protected by a specific Body Computer fuse.
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When operations are carried out on the airbag system, the following safety recommendations must be closely followed. For more details |