Airbag didn't deploy

[herbaljim]

I was rear-ended this afternoon in my 328i while at a complete stop by a another BMW (Z3) doing 40 - 50 mph. He caught my right rear corner slamming me into the car in front of me. I'm assuming by the damage it totaled his car and his airbag deployed. Even with fairly extensive front end damage (right fender, bumper, and hood crushed) neither the driver or passenger airbag deployed...this concerns me. Does anyone have any idea why there was no sign of an airbag?

[fshubert]

First, I hope you and any occupants are OK. I guess if I (you) had to be hit by anyone, a fellow BMW owner would make it a but more palitable. Airbags are deployed based on measurements from accelerometers in the car. If some predetermined G-force is not met, the bags won't deploy. You could have the dealer verify a properly functioning system when the car is repaired but given you were hit from behind (negative G's) and then hit the car in front of you (positive G's), you may not have hit hard enough (for the car, not you) to have the bags deploy.

[TeaRoy]

Again - hope you're okay. But assuming you ARE okay then I would say the airbag system worked perfectly well. No sense in deploying if you didn't need them. Believe you me, airbags can do significant damage to YOU. They can save a life, but I have seen them do much damage to many folks.

[ErinFaulk]

Again - hope you're okay. But assuming you ARE okay then I would say the airbag system worked perfectly well. No sense in deploying if you didn't need them. Believe you me, airbags can do significant damage to YOU. They can save a life, but I have seen them do much damage to many folks.
That is so true. IT does seem like the system worked correctly.

[herbaljim]

I am fine but my wife has a knot on her head but we aren't sure what she hit her head on. She had her seat belt on. I talked to the dealer about it yesterday and he said that we have to be doing at least 15 mph in any situation for the airbags to deploy. I'm not sure if he was making excuses but that seems rediculous to me since I can think of half a dozen instances where I could be at a dead stop and I would want the airbags to deploy. I'm fine with the fact that mine didn't deploy but it might have saved my wife from a two day (and counting) headache if hers would have.

[Beer Goggles]

MPH doesn't matter...your dealer knows NOTHING about that stuff. If you want an answer call BMW.

But realistically if you walked away with a bump you didn't need airbags.

[Blue330i2006]

MPH doesn't matter...your dealer knows NOTHING about that stuff. If you want an answer call BMW.

But realistically if you walked away with a bump you didn't need airbags.

Correct. Airbags WILL break your nose almost every time let alone other bruises to your face. be glad it didn't go off.

[alexC01]

A few years ago I had an E36 and crashed at almost 120 MPH (no, it was not in the USA). The car was a total loss, but the cabin was perfect after the crash. The airbags deployed and I looked like I had been hit by Mike Tyson, but no broken nose or anything else. And by the way, back then (1994) they were 1st. generation airbags. Today's airbags are 2-stage, which means that they will not deploy in full force if not needed. In any case, I guess 120 MPH would have brought stage 2 anyway...

I was so impressed with the fact that I walked out of the car without even a scratch that I bought another BMW the next week with the insurance money.

[mryakan]

A few years ago I had an E36 and crashed at almost 120 MPH (no, it was not in the USA). The car was a total loss, but the cabin was perfect after the crash. The airbags deployed and I looked like I had been hit by Mike Tyson, but no broken nose or anything else. And by the way, back then (1994) they were 1st. generation airbags. Today's airbags are 2-stage, which means that they will not deploy in full force if not needed. In any case, I guess 120 MPH would have brought stage 2 anyway...

I was so impressed with the fact that I walked out of the car without even a scratch that I bought another BMW the next week with the insurance money.
I find it hard to believe you walked away with minor injuries from a 120mph crash. The dummies they use in crash tests crack up at 40 mph impacts. You must have slowed down quite a bit before hitting whatever you hit or you hit something going at a speed differential much much less than 120 mph (e.g. if you rear ended someone going 80 mph then in essence it is like you crashed into a stopped car at 40 mph). If indeed you hit a still object at 120 mph and walked away from that then I'd look for that angel that was in your passenger seat and thank it.

[alexC01]

Of course it was not a frontal crash at 120 MPH... There was a mudslide on the highway and the car went into a spin, hit the median divider, then the right side guard rail, which caught on the front right wheel, ripped it off while sending the car into the air like a football. After spinning several times while going down a small cliff (about 40 ft), the car came to a sudden stop after landing on a protruding boulder. I will post some pictures tomorrow when I get to my office and I can scan them.

It was really horrifying, but I walked out of there unscathed. I climbed back to the highway -took me almost 20 minutes from the time of the crash, to calming down and then climbing back- and the police was already there. They were saying that they will need to send rescuers down there... I told them that it was my car and that I was the driver. The police response was like "this is not the moment for stupid jokes, someone can be seriously injured or dead down there". Then I showed them my keys and said again, "seriously, this is my car"; then the police officer's words were EXACTLY yours: "you must have a really nice guardian angel to walk out of there alive..."

Yes, a nice guardian angel... and BMW's german engineering!

[WHITEXi]

I believe the sensors actually know how sudden the deceleration of your vehicle is along with impact thus maybe that is why they did not deploy. Your were stopped and there not supposed to go off under a certain speed also as the dealer stated from what I was told. This if I had to guess was to lower the costs due to low impacts say slight fender benders or a bump, but im not certain on this. Also as stated before any car 98 an up was equipped with 2 stage airbags. They deploy slower in slower collisions and faster in faster ones.

Found this with a quick google
http://midsouthrescue.org/id7.html
Example: As we seen before, if your car is running 30 mph, your body is also running 30 mph. If the car hits a wall and suddenly stops your body not being a part of the car is still traveling at 30 mph. causing you to lunge forward. That sudden slowing of the car is called deceleration.
These sensors works on the same principle, The sensor housing being part of the car, stops at the same time as the car but, the internal parts (like your body) are still moving at 30 mph, causing them to lunge forward and contact an electrical switch completing the circuit.

This electrical impulse is then sent to a control module, or airbag brain. The control module is simply a small computer that receives impulses from many sensors, sorts them out, or decides which airbags to deploy, and sends an impulse to the appropriate destinations.
To prevent airbag deployment in small fender benders, the control module can not deploy an airbag from this one signal. Every control module must receive two or more impulses to deploy an airbag. This second impulse comes from the safety or arming sensor. This sensor is usually mounted inside the vehicle and must experience a sudden deceleration just like the crash sensor.

[Beer Goggles]

So wait you were going 120mph in the rain?

[FORDMANWITHA330]

I have been on hundreds of vehicle accidents in my career. Everything from minor fender benders to 140 MPH impacts on the freeway (70 MPH + 70 MPH head-on). To explain when & why an air bag or supplemental restraint system will deploy would require a lot of your time. What I can tell you is that the Germans have it down. Most of the car manufacturers today, have very sophistocated safety systems. These systems work with various inputs from sensors regarding "G-Force", Intrusion, Speed, etc. Then you have to trust the computer to make safety decisions. Some times the bags won't go off if the impact is above the bumper with minimal radiator support compromise. Usually looks worse than it is.

Every year, Mercedes, BMW, Toyota, and several other Manufacturers allow us to completely tear apart brand new cars. From $20,000 to $90,000, the new cars are remarkable. However, the Germans always impress me. But, the hard part is extricating you from the crumpled metal once you've survived the initial impact.

One last story. Rolled on a head-on a few weeks ago.....2008 Audi A8 head-on into a Mitsubishi Montero. Audi A8-Air Bag deployment, Seatbelts on, moderate intrustion. Killed the Driver & the 12 y/o child in the back seat (Rapid Deceleration). Mitsubishi Montero-Air Bag deployment, Seatbelts on, Major Driver's side intrusion. Killed Front Seat Passenger who was talking to me until we got her out of the car, Driver survived with major trauma and died 4 days later. Mid size SUV vs. Very Safe full size Audi........Bad day for everyone, even us.

P.S. Keep an eye on your wife. Sometimes head injuries surface days later.

Good Luck & God Bless

OK, One More Story. HOT OFF THE PRESS!!!

We just cleared a 3 car accident. Newer Chevy 1500 4X4, Chevy 4 door Sedan, Jeep Grand Cherokee. Jeep goes head-on/deflected with Chevy Sedan, then head-on into stopped Chevy 4X4. Jeep-Air Bag Deployment, minor intrusion NO Injuries. Chevy Sedan-Moderate intrusion, NO Air Bag Deployment, minor injury. Chevy 4X4-Front Bumper Damage, NO Air Bag Deployment, Driveable, NO Injuries. Better story, no one transported, no one died. Just another example of the variation of Air Bag Deployments.

P.S. To all the subscribers, PLEASE tell everyone you know, "Red Lights, Sirens, Air Horns, PULL TO THE RIGHT". I know the laws haven't changed for at least the 27 years I've been driving. I know it's inconvenient to pull-over. Just in my City, we're rippin' up & down the streets & highways 13,000 times/calls each year. Last year, we lost an Engine (Total Loss) out of my Station, because someone failed to yield the right of way. Public's falt. My Brothers & Rig hurtin'.

[wsolveson]

Weird: I just totalled my X5 slamming into another SUV that was spinning out of control. I was going 45 MPH. The crash disintegrated my front bumper and grill and crumpled my hood. The driver behind me said the impact lifted my rear wheels off the ground. I walked away, fine, but my airbags did NOT deploy. Are those German engineers good, or what? How did they know I was not going to die? I miss my X5, but am not sure about another.

[02325]

i know this is an old thread, but

i have a 07 328 coupe at work. he was run off the road and hit an embankment. the whole frt is a loss. the only thing it blew was the bst cable on the batt. str wheel bag and buckle are all ok. the computer knows what to do and when to do it.

I have seen several wrecked bmw and the bags not go off. its not that uncommon.