General description

GENERAL DESCRIPTION

The car has a safety system complete with:

• Airbag for frontal protection of driver and passenger.
• Side airbags

The system actuates:

• the airbags on the driver and passenger side in case of frontal collision of a certain severity.
• In the case of a side collision of a certain severity, the side airbag on the collision side alone is actuated.

The system is made up of the following components:

• ECU
• Driver’s side airbag
• Passenger’s side airbag
• Sensor for automatic disabling of passenger’s side airbag (only present up to June ’99)
• Side collision sensor on left doorjamb
• Side collision sensor on right doorjamb
• Right side airbag
• Left side airbag
• Diagnostics socket for checking the system with Examiner or other diagnostics instruments

ECU

An ECU manages the entire system by controlling all the components and activating, when necessary, all the retrain systems (pretensioners and airbags).

Operation in the case of frontal collisions

The ECU contains an accelerometric sensor whose signal, appropriately processed by a microprocessor, detects the severity of a collision, and consequently decides to activate the airbag.

The second sensor has safety functions and consents to activation of the airbags. The ECU detects only front collisions. It does not intervene whatsoever in cases of side collisions, rear collisions or rollovers.

Operation in the case of side collisions

On the doorjamb of the front doors there is an accelerometric sensor that detects side collisions and transmits a signal to the control unit.

SIDE AIRBAGS

Collision sensors

On the doorjamb of the two front doors is an accelerometric sensor which, in the case of side collisions, transmits a signal to the control unit.

This signal is appropriately processed inside the control unit, which consequently decides whether or not to activate the side airbag on the side collision where the impact was detected.

In fact, the control unit has a second safety sensor which detects side collisions (much like the sensor that detects frontal collisions) and consents to activation of the side airbag on the side of the collision.

This sensor is positioned so as to detect impacts only on the side on which it is located: e.g.: the sensor on the driver’s side doorjamb detects only collisions on the left and not from the upper right side.

NOTE: The sensor must always be mounted with the arrow pointing towards the front of the vehicle.

Side airbag

The side airbag is housed on the external part – toward the window – of both front seats.

It consists of a container – built into the seat back – that houses the gas generator and the folded bag.

The container is fixed to the frame of the seat back by means of a bracket.

The gas generator can be activated electrically by means of a signal from the ECU, whereby a charge of propellant is fired and releases a compressed gas (Argon) which expands in the cushion. The side cushions are smaller than the front cushions.

Cushion deflation – after being inflated by the gas – is immediate, thanks to a hole located on the rear part of it.

The seat upholstery has seams with predetermined breakage lines which allow the complete release of the cushion.