TATA PUNCH-SERVICE MANUAL

SUPPLEMENTARY RESTRAINT SYSTEM (SRS) 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 connect 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 pre-tensioners are get triggered through ECU signal. The load limiter in the seat belts is a mechanical device which gets activate when the forces on the occupant upper body region crosses a defined force threshold limit. WARNING For driver RPDLL, Anchor pre-tensioner and for Co-driver RPLL should fit only in the vehicle having both frontal airbag. COMPONENTS 1. ECU 2. Remote Sensors  Front remote sensor / Front Impact Sensor 3. Air bags  Driver air bag  Passenger air bag 4. For driver RPDLL, Anchor pre-tensioner and for Co-driver RPLL 5. Clock spring 6. Airbag warning lamp 7. Airbag warning labels