Warning! Airbags do not replace seat belts. Moreover, when the car is moving, the driver and front passenger must be sure to wear their seat belts, since in the event of a traffic accident, the deployed airbag itself can cause serious injury to a person who is not wearing a seat belt.
The SRS system includes the following elements:
- a driver airbag module, located in the steering wheel hub and consisting of a folded airbag shell, a gas generator and an accelerometer that measures negative vehicle acceleration;
- front passenger airbag module (installed depending on the vehicle), located in the instrument panel on the passenger side and consisting of a folded airbag shell, a gas generator and an accelerometer that measures the negative acceleration of the car;
- an electronic control unit installed under the lining of the floor tunnel and controlling the system;
- seat belts.
The impact force in a traffic accident is determined by the electronic control unit (ECU) passive safety systems using electronic accelerometers. At the signal of the accelerometers, the control unit activates the airbags for the driver and passenger.
If the vehicle is equipped with pre-tensioners for the driver and front passenger seat belts, the electronic unit, having received a signal from the accelerometers, increases the belt tension before activating the airbags. Pretensioners provide a timely response to an emergency deceleration of the car, pulling the driver and passengers to the seatbacks, and also exclude their further movement forward by inertia and injury from a deployed airbag. In the event of a frontal impact of a certain severity, the safety computer issues a command to the pyrotechnic elements of the pretensioners.
Note. The seat belt pretensioner mechanism is always activated before the airbag.