Operations of SRS Airbag

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(1)In a collision, the airbag sensor detects the degree of the impact and when the degree exceeds the specified value of the center airbag sensor assembly (airbag sensor assembly), the initiator in the inflator is ignited.
(2)The initiator combusts the enhancer and propellant grain, and it generates a large amount of gas at that moment.
(3)The gas inflates the bag to decrease the impact to the occupants and rapidly escapes through discharge holes at the back of the bag. This reduces the force of impact to the bag, and also ensures an adequate field of view.
CAUTION:
After the airbag deploys, some smoke along with the nitrogen gas is released from the discharge hole at the back of the bag. This is not harmful even if it is inhaled. But when it comes into contact with the skin, be sure to wash off any residue as soon as possible to prevent the possibility of minor skin irritation.
An airbag that deploys instantaneously may cause a slight scratch, burn or swelling.
The airbag module parts (steering wheel, dashboard) become hot for a few minutes, but the bag itself does not become hot.
An SRS airbag is designed to deploy only once. Therefore, parts related to the airbag have to be replaced after deployment.
Operation

SRS Airbag will deploy (driver, passenger)
The SRS front airbag system is designed to activate in response to a severe frontal impact
SRS front airbags will deploy if the severity of the impact is above the designed threshold level, comparable to an approximate 20 km/h -25 km/h (12 mph -15 mph) collision when impacting straight into a fixed barrier that does not move or deform.

If the severity of the impact is below the above threshold level, the SRS front airbags may not deploy.

However, this threshold velocity will be considerably higher if the vehicle strikes an object, such as a parked vehicle or sign pole, which can move or deform on impact, or if it is involved in an underride collision (e.g. a collision in which the nose of the vehicle “underrides,” or goes under, the bed of a truck, etc.).

SRS airbag will not deploy (driver, passenger)
(1)SRS front airbags are not designed to inflate if the vehicle is involved in a side or rear collision, if it rolls over, or if it is involved in a low-speed frontal collision.
(2)SRS front airbags may deploy if a serious impact occurs to the underside of the vehicle. Some examples are shown in the illustration.
4.SRS airbag will deploy (side, curtain shield)
(1)Side airbag + curtain shield airbag (front only)
<1>SRS side airbags and curtain shield airbags are designed to operate when the vehicle compartment receives a side impact.
<2>When the vehicle receives an impact from the diagonal direction or the side impact illustrated on the left but not at the vehicle compartment, the SRS side airbag and curtain shield airbag may not operate.
(2)Side airbag + curtain shield airbag (front + rear)
<1>SRS airbags and curtain shield airbags are designed to operate when the vehicle compartment receives a side impact or quarter back side impact.
<2>When the vehicle receives an impact from the diagonal direction or the side impact illustrated on the left but not at the vehicle compartment, the SRS side airbag and curtain shield airbag may not operate.
SRS airbag will not deploy (side, curtain shield)
SRS side airbags and curtain shield airbags are designed not to operate when the impact is to the front or back, or in a rollover, or side collision at a low speed.

Types
1.Types of SRS airbags
Front airbag for driver (single-stage, dual-stage)
Front passenger airbag (single-stage, dual-stage)
Side airbag
Curtain shield airbag (only front, front + rear)
2.Types of airbag sensors
Front airbag sensor
Center airbag sensor assembly (airbag sensor assembly)
Side airbag sensor (side and curtain shield airbag sensor)
Curtain shield airbag sensor (only when curtain shield airbags are installed both at the front and rear)
Side door sensor(only for 2-door and 3-door hatchbacks with side airbag)
Seat position airbag sensor(only with the dual-stage airbag)
Occupant detection sensor
Some types have airbag sensor No.2 that plays a role as a front airbag sensor on the passenger seat floor (example: Dyna).

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