I was extremely glad to have been in my 2002 V70 when another car slammed intomy rear-end(maybe going 40-50 mph). The cops suggested that in another car this would have been quite a different accident. I have a question about air-bags.

There was an SRS error (I think), and the car wouldn't start, although the electical system turned on (then shut down). The car frame bent (rear passenger doors wouldn't open). I was at a full stop and although my foot remained on the brake, the impact moved my car the two or so feet into the car in front of me, only giving that driver a shove, but zero damage to that car. My front bumper was mis-aligned, but certainly not the damage like in the rear (the car was say 2" shorter). Although I walked away (a little shaken, of course), my lap belt left bruises on my thighs. I did not hit the steering wheel or windshield on impact, but I also saw the car coming in my rear-view, so was ready.

As you all probably know, the battery is in the rear. Turns out the battery that sends a signal to the "sem" computer box, cut out. The sem died (the dealer replaced it to see if the car would start, which it didn't so the car was officially "totalled").

So: On a substantial rear-impact, should my air-bags have gone off? Is there a safety-design issue lurking here?

 

This subject is very touchy about the SRS systems on these cars and when they should go off.
I think it is like this with all cars but we only see the Volvo ones.
In my opinion with out seeing pics of your car it probably should have gone off.
Did you say the SRS light was on before the Accident?

Here is another one here is a couple of pics of a 850 that was hit by a navigator doing between 35 to 40 MPH and none of the air bags went off.

 

Glad you were in a Volvo.

In general (there are always exceptions[8D]), the air bags are not supposed to deploy upon rear-end collision. They are designed to deploy upon frontal (and side impact for SIPS) collision, and even so, in certain cases of frontal collisions they are not supposed to deploy to avoid harming the passengers. There are specific parameters, such as the location of the impact, vehicle speed, etc that have to be met in order for the SRS to go off. But the seat belt pre-tensioner & retractorshould kick in for any type of collision (even for speed bumps[8D]).

Anyway, you have proven another casethat Volvos are the safest cars available to the public.


JPN

 

No, the SRS light was definately not on before the accident. The back of the car looks quite a lot like the picture of the 850, but a little worse. The rear bumper took a lot more damage (makes sense since I was hit with a regular Dodge car, not a SUV), but the rear lift-door is about the same. My front-end, however, looked nothing like in the picture. No apparant hood damage, just the bumper. So if the air bags are not expected to go off with the kind of damage that 850 took to the front-end, I shouldn't expect mine to have gone off.

However, there was some kind of impact throwing people forward in that 850. I'm somewhat amazed the bags didn't go off and that Volvo isn't on top of this. I guess with a one-two punch (first rear, then front), there's some added risk. Thanks for your comments.

 

Why would one want the front airbags to deploy in a rear end collision? And if the front sensor was that sensitive wouldnt it increase the likely hood of the airbags deploying if say somone backed in to you in a parking lot which would hurt alot. As someone who has taken a head on collision into a cement wall with the airbag deploying and yes hurting but didmoregood then harm (Saab 900 first year of standard airbag). I am sure with the extensive testing done there is a very good reason that they would not deploy. I would think from a physics standpoint the airbag if deployed and it does so in miliseconds would throw the driver to the seat not preventing whiplash. I don't know if you have ever seen or heard of the Saab's SAHR (saab active head restraint) that moves the headrest forward upon rear end collision to in theory catch the head and prevent whiplash but that is the only rear impact deploying system I have heard of. Anyway I thought that it was an interesting idea bySaaband glad to hear you were in aswedish car and are ok.