Air Bag Systems: Description and Operation

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)




SRS Configuration
The air bag deploys if the air bag diagnosis sensor unit is activated while the ignition switch is in the ON or START position.

The collision modes for which supplemental restraint systems are activated are different among the SRS systems. For example, the driver air bag module, front passenger air bag module, front seat belt pre-tensioners and seat belt buckle pre-tensioner assemblies are activated in a frontal collision but not in a side collision.




SRS configurations for some collision modes are as shown in the table.




Front Seat Belt Pre-tensioner with Load Limiter
The seat belt pre-tensioner system with load limiter is installed for both the driver's seat and the front passenger's seat. It operates simultaneously with the SRS air bag system in the event of a frontal collision with an impact exceeding a specified level.

When the frontal collision with an impact exceeding a specified level occurs, seat belt slack resulting from clothing or other factors is immediately taken up by the pre-tensioner. Vehicle passengers are securely restrained.

When passengers in a vehicle are thrown forward in a collision and the restraining force of the seat belt exceeds a specified level, the load limiter permits the specified extension of the seat belt by the twisting of the ELR shaft, and a relaxation of the chest-area seat belt web tension while maintaining force.




Front Side Air Bag
Front side air bag modules are built into the front seatback assemblies.
Vehicles with side air bags are equipped with labels as shown.




Side Curtain Air Bag
Side curtain air bag modules are located above the vehicle headlining.
Vehicles with side curtain air bags are equipped with labels as shown.

Occupant Classification System (OCS)
The occupant classification system (OCS) identifies different size occupants, out of position occupants, and detects if child seat is present in the front passenger seat. The OCS receives inputs from the occupant classification sensor (located inside the passenger seat cushion assembly) and belt tension sensor (part of the passenger front seat belt assembly and located at the belt anchor location). Depending on classification of the passenger, the OCS sends a signal to the air bag diagnosis sensor unit. The air bag diagnosis sensor unit uses this signal and the seat belt buckle switch RH signal to determine deployment or non deployment of the passenger front air bag in the event of a collision. Depending on the signals received, the air bag diagnosis sensor unit can disable the passenger front air bag completely.

NOTE: In case of customer concern, CONSULT-II can be used to confirm the passenger air bag status (readiness).




Passenger Air Bag Status Conditions

Direct-connect SRS Component Connectors
The following SRS components use direct-connect style harness connectors.
- Driver air bag module
- Front passenger air bag module
- LH side front curtain air bag module
- LH side rear curtain air bag module
- RH side front curtain air bag module
- RH side rear curtain air bag module
- Front LH seat belt pre-tensioner
- Front RH seat belt pre-tensioner
- Seat belt buckle pre-tensioner assembly LH
- Seat belt buckle pre-tensioner assembly RH

Always pull up to release black locking tab prior to removing connector from SRS component.




Always push down to lock black locking tab after installing connector to SRS component. When locked, the black locking tab is level with the connector housing.