Distributed SRS System

System Components

1. Airbag crash sensors
2. SRS warning light (airbag)
3. Rotary coupler
4. Driver's airbag module
5. Passenger's airbag module
6. Airbag diagnostic socket
7. Airbag diagnostic control unit
8. Airbag harness



System Operation
The airbag supplementary restraint system (SRS) is a safety device which, when used in conjunction with the seat belt, is designed to protect the driver and front passenger by operating when the vehicle receives a frontal impact (in the area shown) exceeding a certain set speed.

Front Impacts:

In the event of a frontal impact, when the airbag diagnostic control unit and one of the airbag crash sensors senses the impact, the diagnostic control unit triggers the airbag modules which fires an igniter. This in turn ignites tablets of sodium azide which generate a large amount of Nitrogen gas leading to airbag inflation in approximately 30 milli-seconds.

When fully deployed the airbag offers additional protection to the front seat occupant. As an occupant moves into the airbag it immediately discharges the gas from vent holes to provide progressive deceleration and reduce risk of injuries. The whole process is completed in approximately 0.3 seconds.

! WARNING: All the airbag system components, including the wiring harness, MUST be renewed after the airbags have deployed.







SRS Warning Light (Airbag)
The warning light in the instrument pack illuminates after the electrical circuits are switched on whilst a system check is carried out. After about 7 seconds the warning light will go out. The system checks the airbag diagnostic control unit, airbag crash sensors and the airbag harness.

In the event of a fault in the system the warning light will Illuminate and begin modulating. The airbag diagnostic control unit logs the fault which can only be accessed using TestBook Scanner.