Air Bag Systems: Description and Operation

Airbag System Function
- The system is activated by a signal from a collision sensor which measures vehicle deceleration -or negative acceleration- equal to a direct head-on collision of at least 18 km/h (11.8 mph) against a solid (immovable) object.
- The electric circuit is made and the gas generator ignites. The swift combustion of the solid fuel mixture releases non-toxic gases which fill the folded airbag -or airbags- within approximately 30 milliseconds.
- As the occupant's body plunges into the airbag, gas escapes -at a controlled rate- through 2 apertures which will help ensure that the driver is caught gently.

System Monitoring
- Airbag system is monitored continuously by a diagnosing unit from the point in time when the ignition lock is turned to position "1". The indicator lights up and goes out again after about 6 seconds indicating that the system is ready for use.
- If this indicator light comes on again a fault has been detected in the system.
- Self-diagnosis - interrogate the fault memory with the BMW DIAGNOSIS SYSTEM.