Air bag didn't deploy--should I be concerned?

A few years ago I bought a used 2006 Toyota Rav4. I was rear ended in 2010 and my air bag did not deploy. Only damage was to back bumper. Yesterday I was again rear ended. I am guessing the only problem will be a damaged bumper, but once again the air bag did not deploy. This time I had an elderly couple in my car and both said the impact was hard enough that my air bags should have deployed. No one was hurt. How much force does it take to make the air bags deploy? Should I be concerned? If so, can the body shop check my air bags or do I need to go to the dealer for that?

No need to be concerned. Getting hit from the rear is not going to deploy the air bags. Every time you start the car the cars computer checks the air bag system. Look for the air bag system light on the dash. You can have the system scanned if it will make you feel better. They don’t go off like in the movies. A lot of things have to happen for a air bag to deploy. Its starts with a side hit or front hit. You have to be moving over a set speed and have decelerate at a set rate.

I wouldn’t worry about it. I rear ended a truck a few years ago at probably 25-35 mph in my '96 Contour and the air bags didn’t deploy. I don’t know what amount of impact it has to be to deploy air bags, but you don’t want them deploying at every light impact. At the speed the air bags deploy they could be more dangerous than the impact.

I have some friends that were rear ended. The airbags did not deploy on the first impact but did deploy when they hit the car in front of them.

Airbag deployment is pretty violent and can cause serious injurys on its own. They have to inflate in an instant or they will inflate to late to do any good.
That’s why they are not set to trigger for every fender bender. If they did, they could easily cause more injuries than they prevent.

As mentioned before, air bags do not deploy in a rear impact. They would be of no benefit, as your body is not thrust forward in the same fashion as a front end collision. Your airbags do a self test every time you start the car. As long as the light comes on and then goes out at startup, the system is operating as designed.

I wouldn’t worry, but make sure it does at TXdealer describes. Sometimes they’re taken out of used cars and sold. Rare, but it happens.

The airbag system is not just “hardness” dependent. Your vehicle has a network of not only accelerometers but crush/body deformation sensors that feed into a central computer that decides if all the parameters are met for airbag deployment.

Pissed me off when I was driving my buddy’s pontiac sunfire and I mashed the brakes violently at 60+ to avoid an unguided ballistic missile (old lady with landyacht)… I avoided the collision but the poorly designed computer system blasted the airbag into my face and hurt my hand. Cost of replacing airbags exceeded the value of the car… so we bought it back from the insurance, bought beer, and cut the airbags out.

Front airbags are set up to deploy on rapid deceleration. When hit from behind you receive a rapid acceleration (opposite of deceleration). Unless the rear impact causes you to hit something in front of you the front airbags will not deploy. If you think about it this makes total sense. As the car behind you rear ends you your body is forced into your seat and away from the steering wheel and dashboard. The airbag would provide zero protection.

When you hit something in front of you your body flies forward toward the steering wheel and dashboard. NOW you WANT the airbag to deploy to save your life. Airbag deployment is scary, explosive, and expensive. You would only want to have an airbag deploy when it will absolutely make a difference.

I know a lot of you kids have grown up with air bags and don’t know any better, but you can sustain quite an impact with seat belts and shoulder harness on and not get hurt. Contrary to air bags exploding in your face breaking ribs and noses and killing kids. We just had another 25 year old die in a rollover with no seat belt and I believe part of the reason kids don’t use belts is that they think the air bags will protect them. When the crash is from the side or severe enough to deform the passenger cage, the bags will do some good.

Just as everybody else stated, don’t worry about it. They were not supposed to. There are no sensors in the rear and if it were a front hit it would also depend on where the impact took place in relation to sensor position.

You stated an elderly couple was in the car with you and they stated they should have blown. How would they know? With all due respect they haven’t a clue about these things.