Air Bags Did Not Fire
03-17-2017, 04:40 AM
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Air Bags Did Not Fire
The wife and I were in an accident in our '08 unlimited with enough front right force to crush the bumper and bend the frame. Although about a 90 degree impact with another car, our front right to her front left (she ran a stop sign), the air bag did not fire. I am a little concerned about the system. Question: Does an '08 have a "crash record" of collision events such as airbags, belts, speed, etc. I understand these items are recorded by a module in some vehicles. I would like some clue about the airbags. Don Parrish
03-17-2017, 08:36 AM
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Could be the impact was such that the air bags were not called for.
However...
The '08 (and other years near that) has several recalls on the air bags for not firing because of a clockspring defect, and for firing with shrapnel.
Take it in and have it looked at.
However...
The '08 (and other years near that) has several recalls on the air bags for not firing because of a clockspring defect, and for firing with shrapnel.
Take it in and have it looked at.
Last edited by ronjenx; 03-17-2017 at 08:41 AM.
05-29-2017, 06:30 PM
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The wife and I were in an accident in our '08 unlimited with enough front right force to crush the bumper and bend the frame. Although about a 90 degree impact with another car, our front right to her front left (she ran a stop sign), the air bag did not fire. I am a little concerned about the system. Question: Does an '08 have a "crash record" of collision events such as airbags, belts, speed, etc. I understand these items are recorded by a module in some vehicles. I would like some clue about the airbags. Don Parrish
From experience... Your going to have at min of 25mph impact before deployment. Rate of speed, G's and point of impact are all calculated before deployment.
05-30-2017, 06:14 AM
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05-30-2017, 07:06 PM
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I'd like to shine some light on your question about the airbag control modules. I was a supervisor for the accident reconstruction team for a large police department. These reconstructions often dealt with traffic fatalities. The airbag control module, or crash data recorder, record information relating to a traffic collision. This information varies by year, make, model, and production date of the vehicle. This information is not accessible to you, and even if it was, you do not have the equipment to download, image, and read the information. Usually, only car manufacturers, law enforcement, and specialized reconstruction companies (engineers, attorneys) have this information. Even then - very few people have the updated software, all of the required cables, components, etc.. to properly read the vehicle.
In addition, depending on year, make, model, and production date of the vehicle, once you turn on the vehicle and attempt to drive it, the memory of those modules are erased. Once the memory is erased, you cannot retrieve the information easily. (I'm sure it might be possible, but you'd have to remove the module and ship it to the manufacturer or other types of forensic IT person to get it back).
Some of the information that could be stored, would be speed, acceleration, braking, seat belt sensor information, all the up to much more complicated physics, again, depending on the year, make, model, etc..
As for why/when an airbag fires, there is a complicated algorithm that again varies by year, make, model, etc... that will tell the sensors the crash is serious enough for the airbags to fire. If the sensors don't detect that the crash is serious enough, or if it doesn't hit on the correct algorithm to fire the airbags, they won't fire. I've seen rollovers without airbags firing, and I've seen parking lot fender benders where the airbags fire. Perhaps an engineer on the board could shine more light onto this.
One other thing, if your jeep is brand new, or was purchased new, you shouldn't have any issues. If you purchased it used, perhaps the airbags were taken out and/or damaged or deployed previously. I've seen people with used cars that thought the air bags were there, when in fact, they had been taken out or stolen previously, and the new owner had no idea.
Hope this helps a little.
In addition, depending on year, make, model, and production date of the vehicle, once you turn on the vehicle and attempt to drive it, the memory of those modules are erased. Once the memory is erased, you cannot retrieve the information easily. (I'm sure it might be possible, but you'd have to remove the module and ship it to the manufacturer or other types of forensic IT person to get it back).
Some of the information that could be stored, would be speed, acceleration, braking, seat belt sensor information, all the up to much more complicated physics, again, depending on the year, make, model, etc..
As for why/when an airbag fires, there is a complicated algorithm that again varies by year, make, model, etc... that will tell the sensors the crash is serious enough for the airbags to fire. If the sensors don't detect that the crash is serious enough, or if it doesn't hit on the correct algorithm to fire the airbags, they won't fire. I've seen rollovers without airbags firing, and I've seen parking lot fender benders where the airbags fire. Perhaps an engineer on the board could shine more light onto this.
One other thing, if your jeep is brand new, or was purchased new, you shouldn't have any issues. If you purchased it used, perhaps the airbags were taken out and/or damaged or deployed previously. I've seen people with used cars that thought the air bags were there, when in fact, they had been taken out or stolen previously, and the new owner had no idea.
Hope this helps a little.
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05-30-2017, 07:20 PM
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05-30-2017, 07:45 PM
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For air bags to deploy a couple things need to happen. On your jeep the impact generally needs to be within 30 degrees from the centre of the vehicle. Also as well as either of the front sensors being triggered there is also a module in roughly the centre of the vehicle under the dash on the floor that needs to trigger as well before airbag deployment. ( I'm an autobody tech by the way)
