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SUPPLEMENTARY RESTRAINT SYSTEM (SRS)
1
1.1. WORKING OF RESTRAINTS
RESTRAINTS WITH AIRBAGS
This restraint system falls under the category of
Supplementary restraint system.
SUPPLEMENTARY RESTRAINT SYSTEM
(SRS)
Air bags are the secondary restraint system, as the
vehicle occupant for the activation of air bags
requires no action.
!! WARNING
Every occupant shall wear seat belts whenever
they ride a vehicle. This is applicable whether a
vehicle is equipped with supplementary restraints
systems (SRS) or not.
WORKING OF SRS
Whenever there is an accident the sensor mounted
remotely sends crash signal to the ECU. The type
of accident and its severity, determines the time-to-
fire different airbags in the system. The basic
function of an airbag is to provide cushioning effect
to occupants.
There are remote sensors mounted for sensing
different frontal and side accidents. These sensors
are connected to the electronic control unit (ECU)
of the system. When an accident event input signal
crosses a pre-defined threshold level in ECU, the
ECU triggers the relevant restraints components in
the system. This helps in providing necessary
protection to occupants. The airbags and seat belt
pretensioners get triggered through ECU signal.
The load limiter in the seat belts is a mechanical
device which gets activated when the forces on the
occupant upper body region crosses a defined
force threshold limit.
WARNING
RPLL seat belts for Driver and Passenger should
be fitted only in the vehicle fitted with both frontal
airbags.
COMPONENTS
1. ECU
2. Remote Sensors
Front remote sensor / Front Impact Sensor
Side remote sensor / Side Impact Sensor
3. Air bags
Driver air bag
Passenger air bag
Side air bag
Curtain air bag
4. RPLL
5. Clock spring
6. Airbag warning lamp
7. PAB deactivation switch
8. PAB indicator
9. Airbag warning labels