Air Bags

[PRFD101]

Just wanted to let people know and to watch for this. It has become more evident and has even now been posted on the inside of the doors which is not always that visible. It has become evident that even after the airbags have deployed it is still possible for them to once again deploy meaning that you must still watch yourself with already deployed bags. I have not seen this happen yet but still something to watch for. Safety first.

[simfirdept]

We have a chrysler mechanic on our volunteer department and he has said the airbags can be activated from 30-40 mins after impact. The more and more airbags present in these vehicles the more dangerous our job becomes.

[hwoods]

Wow.........

If that doesn't get your attention...... Thanks for the "heads up". Anyone know of any particular make/model that this applies to?? Stay Safe....

[cmjones]

Another challenge is side-impact "curtain" air bags that are made into the top rail between A-post and B-post. Has anyone ran up on these yet?

[dragonfyre]

Re: Air Bags

"It has become evident that even after the airbags have deployed it is still possible for them to once again deploy meaning that you must still watch yourself with already deployed bags."

Are you saying that once a bag has deployed it can once again be deployed or that if the front bags deploy you have to watch for the side bags?

If you're saying the former then I don't know where you get your information from. Once the bags have been deployed there is no way to "re-deploy" the system. The ignitor and the sodium azide have been burnt off so there is no way to create the nitrogen to inflate the bag.

I've been teaching a class on air bags since 1991, get all my info from the manufacturers and have never heard of anything like that.

[Bones42]

dragonfyre, I'll agree with you, I have never heard of a bag re-deploying as a possibility. But, are there not some bags now that have 2 charges, 1 for a slow speed "lesser" inflation and a second charge for a higher speed "larger" inflation? I have not found any information but had heard something about smarter airbags that take speed into the calculation of whether to do a full inflation or less. Just wondering if you have heard anything about that and if so, are there 2 different charges or just 1 that only partially fires?

[ThNozzleman]

"Some cars have "dual stage" airbags, also called Multi-Stage Airbags. They contain two ignitors. One ignitor is designed to deploy (with less power) if the vehicle occupant is a small person, while the other ignitor deploys (with more power) if the occupant is a larger person. One ignitor is always left over after the airbag deploys. And that ignitor is still capable of going off in spite of the fact the airbag looks deployed."

This quote came from http://www.airbaginstitute.com/

[ThNozzleman]

"Always assume a deployed dual stage inflator module has an active second stage because it is impossible to visually determine if both stages have been activated."
From http://www.asashop.org/autoinc/dec2002/collision.cfm

[dragonfyre]

Bob:

I hear what you're saying and visted the websites but according to everything I've gotten from GM (I work at a GM dealership) it doesn't matter which ignitor goes off, the sodium azide is burnt during the deployment no matter which stage, which PSI is chosen.

If there is nothing left to burn, when the 2nd ignitor goes off, how can there be re-deployment?

I'm going to e-mail Keith at the one web-site, I'll let you know what happens.

[ThNozzleman]

I understand your approach; however, it seems to me that merely having two or more separate ignitors would not change the rate or velocity of the single airbag activation, much like a pile of gunpowder would ignite the same, no matter how many matches were used to ignite it. The only way I could see dual stage airbags being able to work as the auto manufactuars claim would be to have two different charges behind the bag, ignited by two different systems; either separately, together, or in series. I'm an ASE certified Master Tech, myself. But, it's been several years since I worked for a dealership (the last being a Chrysler/GMC dealer), so I'm not as involved in the automotive world as I used to be. I would be very interested in getting to the bottom of this issue. I remember installing airbags in the early 90's; we handled the things like a bomb squad on speed. I sure wouldn't want one going off on my precious melon.

[simfirdept]

With my post I'm sorry if I confused anyone but the mechanic has said if there are airbags that haven't been deployed you have to watch because 30-40 mins after impact they can go off. I haven't heard or been told anything by the mechanic about a bag redeploying after it's been deployed.

[canada33]

We bought a book ( I think Halmatro put it out) that discribes where every vehicles airbags are located. Covers just about every vehicle imaginable.

[ThNozzleman]

Thought I'd knock this one back to the top. Anyone else have any info?

[PRFD101]

Started this

Hi there all, thanks for all the discussion, I am going to check which vehicle it was that I got the actual peice out of that said it flat out in on it to warn of the poosiblity of redeployment, it didn't state that if tehy haven't gone off that they might deploy, it actually did state a warning that they can poosibly REDEPLOY, If my memory is correct it was a newer M class mercedes. I am 98 percent sure that was the vehicle we found it in. I know there are alot of mechanics out there but each company does their own thing and one might not know what the other has in their concerns. The only reason it stands out so much is we were so shocked to find this we took that peice with us. All this news is great to hear, Nothing better then learning more with each day. thanks to all

[ThNozzleman]

I dug this up, because I think it's very important. Link to the story about automotive safety devices, including two-stage airbags, on Firehouse.com:
http://cms.firehouse.com/content/art...Id=19&id=22458
I followed the link to the news video, and watched it. The headlights on the vehicle the injured firefighters were working in were still on. If your department does not have a policy of disconnecting batteries (both cables) on wrecked vehicles immediately, you should. I'd hate to be that guy. Also, it appears that two stage airbags are a fact, and should be approached very carefully.