Airbags
Construction and Design

Airbag are assemblies consisting of the air bag (made of Nylon), inflator modules, and sensor housing, electrical connectors (clockspring), airbag retainer, and the cover you see which usually says "SRS" on it. The driver's side bag is mounted in the center of the steering wheel.

TYPICAL DRIVER'S SIDE AIR BAG CROSSECTION



What happens in a Collision

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When you are involved in a frontal collision somewhere in the neighborhood of at least 12-15 mph, a number of things happen very quickly. The sudden deceleration of your vehicle causes 2 SENSORS to send an electrical signal to the diagnostic module. The diagnostic module self tests to confirm that a crash event is taking place, then it allows the signal to trigger the airbag deployment.

AIRBAG Deployment
Below is an illustration of a driver side airbag deployment. The first image is the airbag inflation, the second depicts your contact with the airbag, and the third is your coming to rest in the seat and the deflation of the airbag. This all takes place in about 30 milliseconds. In fact the entire inflation/deflation cycle takes less than 1/2 second. The speed of the airbag inflating is around 200 MPH*. The vehicle hasn't come to a stop at this point, nor hopefully have you lost control of it.
*UPDATE- 1998 is the first model year for De-powered bags. Unfortunately these are NOT standard equipment on all cars.

Driver's Side Airbag
The image below shows the parts of the air bag module in the steering wheel. From top to bottom we have the cover, the airbag assembly, the retainer attached to the steering wheel, the steering wheel, and the 'clockspring'


Photo Courtesy of Autoliv.Inc

The Clockspring allows the steering wheel to move while maintaining the electrical connection to the airbag module.

Passenger Air Bag
The passenger bag is mounted in the top of the dash on the passenger side of the vehicle. Below is a Photographic cross section of a Passenger Side Airbag Module


Photo Courtesy of Autoliv.Inc

Airbag Checks What you can do for your Airbag System.

• When you get in your vehicle and turn the key,
  look at the dash to find your Air bag or SRS light.
• It should come on for 7-10 seconds and then go out. This tells you all is well with the Airbag System.
• If the light does not come on, HAVE IT CHECKED. After all, it could just be a burnt out light bulb.
• If the light does not go off after this period(usually 7-10 seconds) there is a problem
• If the light comes on while you are driving, it also needs attention.

You need to take it to a repair shop that has the equipment to diagnose and repair the problem.

Supplemental Restraint Systems cannot be repaired at home. This is not a challenge. Hand held Diagnostic equipment that may read the error codes and may be able to clear them to reset your system are around $3000-$6000. This does not include the cost of the software involved.

In addition to the front Airbags, the car companies are putting Airbags in the doors for side impacts that are not covered by the primary Airbags. They are putting them in the seats for the drivers and rear passengers as well. This increases the cost as well as the complexity of the systems.

Since 1990 the National Highway Traffic Safety Administration, which is responsible for vehicle safety rules and statistics relating to vehicles, found that of 19 drivers killed by airbags, only five of them were wearing seat belts and two of them were determined to be unconscious before the airbag deployed.

All new passenger cars are required to have driver and passenger air bags by Sept. 1, 1997 and all sport utility, minivans and light trucks will be required to have them a year later.

Air bags are SUPPLEMENTAL RESTRAINT SYSTEMS so Buckle Up!