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What is the airbag system/what does it do?

The airbag system is a crucial part of the car's safety system. The car's airbag system can mean the difference between survival and serious injury or death in a crash situation. The airbag system is a very clever and complex piece of kit which is made up of various components, which work together with the airbag control unit ECU, a highly advanced computerised part, to ensure this crucial safety device functions effectively.  The airbag system is referred to as a SRS, which stands for 'supplemental restraint system', which means the airbag system provides extra or supplementary safety protection to the car seatbelt, the primary restraint system, in a crash situation. 

Getting into the details of the airbag system

Airbags are made out of stretchy material and are housed, usually in airbag covers, which protect the airbag and hide it from view. The airbag is compressed tightly beneath this casing, in several areas throughout the car.  Airbags can be placed in all of the doors, on the dashboard, the roof of the car, the steering wheel and in all of the seats. The airbags located in the car doors are situated in the door panel, offering particular protection to the inhabitants in a side impact and rollover crash, by inflating between the inhabitant and the door, avoiding damage to the torso and shoulders. The airbags located in the seats  help to shield the driver and passengers from potential injury, preventing the body and head from hitting the car, particularly in a high impact side collision. The airbag located in the hub of the steering wheel provides protection to the driver in a frontal and rollover crash. The passengers airbag is located either in or beneath the panelling on the passenger dashboard, and acts as a safety device in the same way, cushioning the passenger sitting in the front, in a frontal and rollover crash.  The airbags in the roof are located in a protective casing in the roof of the car above the heads of the driver and passengers, to protect the inhabitants of the car, particularly in a rollover crash or a high impact frontal crash.

Airbags react when there is a crash by filling with air at exceptional speed, creating a pillow which bursts out of the airbag cover or panel it is secured behind and into the car, protecting the people sitting inside the car by cushioning the impact of head or upper body with the interior of the car. The airbag will then deflate afterwards. An airbag needs to spring into action practically as soon as the crash happens. According to studies, an airbag will activate within 55 milliseconds of impact.  You can see why it is imperative that the airbag system is functioning fully, and that vital components, such as the airbag itself, are in sound working order to be able to respond accurately. Passengers and driver need to be seated properly and wearing seatbelts for the airbags to work effectively in a crash and to avoid receiving an injury from the airbags. 

The car's airbag system has airbag sensors which are electronic sensors that detect when the vehicle has crashed and which area is damaged. These advanced sensors monitor and measure factors such as brake pressure, wheel speed and which seats are occupied and sends this information to the airbag control unit ECU which is the control centre of the airbag system. The airbag control unit ECU, also referred to as the airbag SRS control module, will determine if it needs to implement the activation of airbags as well as deciding if functions such as automatic seat belt and door lock are put into place.  The airbag control unit ECU is located in the front section of the car and can be found in various places, such as underneath the passenger or driver seat or hidden in the casing beneath the radio, for example.

What if something goes wrong with the airbag system?

The airbag control unit ECU will regularly carry out routine diagnostic checks of the air bag system. If the airbag control unit ECU picks up a fault, the air bag system warning light will illuminate on the dashboard. Once the airbag system warning light illuminates, the system becomes inactive, which means if you have a crash the airbags will not work, so it is important to address the problem as soon as possible. If any of the airbags are activated then the airbag control unit ECU will need to be replaced or reset by a professional and the airbags will need to replaced as they cannot be reused once inflated.