After they’ve had an accident, some people wonder why their airbags didn’t go off.  Movies and television lead us to believe that airbags go off with the slightest bump.  The reality is much more complicated.  First, airbags come out with great force and speed.  Although getting hit in the face with an airbag is much better than getting hit in the face with the windshield, if the impact of the accident isn’t hard enough that you might be severely injured, the airbags may not be triggered at all….but that’s a good thing because they could do more harm than good.

So what about airbags?   How does your vehicle know when an accident is likely to result in life threatening injuries that would merit deploying the airbags?  Well, there are sensors all around your vehicle that send information to the Supplemental Restraint System (SRS) computer that decides when and which airbags should be deployed.  There are impact sensors that measure the direction and intensity of an impact in the front, rear, and sides of the vehicle.  There are seat sensors that determine if someone is sitting there…as well as how much they weigh.  This way an airbag doesn’t go off when no one is in a particular seat and it can deploy with less force for a smaller person.

The SRS computer takes into account vehicle speed and if there is a rollover.  Built into the computer program are the design specifications of your vehicle as they relate to “crumple” zones in a crash.  As you can imagine, the computer program is pretty sophisticated.

When an airbag actually does go off, there are some things you should know…when the driver side airbag deploys, the steering wheel clock spring is usually damaged and should be replaced.  Also, an “airbag worthy” event triggers all the sensors we’ve talked about…so something as slight as hitting a pothole could cause airbags to deploy.  So after an airbag has actually been deployed, all the SRS sensors should be replaced.

Finally, when you start your engine, you will briefly see the SRS dash light come on and then turn off.  This is a system self-test.  If the SRS light remains illuminated, that means the system has detected a problem that could affect the proper deployment of your airbags.  Although we don’t provide all these services at our shop, we thought these were important tips that can help if you’ve had your airbags deploy in a minor incident.