Passenger side airbag deactivation

The electronic control unit is equipped with suitably calibrated deceleration sensors, through which it detects a collision situation and triggers the reaction of a chemical compound which produces nitrogen through two electric detonators. The gas inflates the two synthetic fibre cushions respectively housed at the centre of the steering wheel and in a compartment of the dashboard in front of the passenger.

Simultaneously, the control unit triggers the pretensioners which prevent the belts from unreeling by a piston operated by a gas generator which pulls the steel cable fastening the buckle.

PASSENGER SIDE AIRBAG DEACTIVATION

The passenger side airbag can be deactivated voluntarily or temporarily by means of the vehicle key. The control switch is located on the side cabinet panel on passenger side and activates (ON) or deactivates (OFF) the passenger side airbag. In this case, the ECU excludes passenger side airbag activation but enables normal operation of the respective pretensioner. This ensures that if a passenger is on board and the switch has been left OFF by mistake, the airbag will not be triggered but at least the pretensioner will operate normally. When the key on OFF, the ECU will also activate the respective “Passenger side air bag deactivated” warning light on the instrument panel.

1. Key switch
2. OFF: Passenger side airbag deactivated
3. ON: Passenger side airbag activated

For further details see "GROUP 55 - ELECTRIC SYSTEM DIAGNOSIS - Section "Air Bag and Pretensioners"."

SYSTEM COMPONENTS

ELECTRONIC CONTROL UNIT

(see "GROUP 55 - ELECTRIC SYSTEM DIAGNOSIS")

DRIVER’S SIDE AIR BAG MODULE

The specifically designed steering wheel is fitted with side controls (3) for the horns and the central part is used to accommodate the actual Air Bag module. It is fastened by two special screws (2) to the rear of the steering wheel.

The module (1) consists of a steel plate covered by a plastic container which forms the centre of the steering wheel. The container encloses the suitably folded cushion and the inflating device. The inflating device contains an electrically activated detonator and a chemical compound (Sodium azide) to produce gas (Nitrogen).

The rear of the cushion has holes which are sized to allow the cushion to deflate immediately after deployment.

The upper part of the module has pre-breakage lines which allow the inflated cushion to come out quickly leaving the module fixed on the steering wheel without the pre-established detached parts.