Airbag deployed while 4WDing

Marko · #1 10-17-2008, 12:18 AM

I need some technical info regarding airbags on an 05 X5 3.0D.

While descending a (approx) 25 degree clay slope of about 10ft vertical, the skid plate under the transfer case hit a small rock and the passenger side airbags deployed (all except the dash). My passenger was injured and not impressed.

I had HDC on and was travelling very slowly. There is evidence of a scrape on the transfer case protection plate and cross-member but there was no impact anywhere else and certainly nothing from the side. The cost of replacing the airbags is $13k and the dealer says it's my fault. It's still under a 3 year warranty.

They have supplied me with diagnostics data showing a crash telegram was sent and triggered the bags - that much I know as I was in the car!

Does anyone know of similar incidents or better still about the dynamics of the airbags system and what it is meant to do (and not do)? I was doing far less than BMW say the car can do when advertising (videos, website pics, description of capabilities) and this just seems plain unsafe. The manual says 45 degrees and there is no mention that the airbags might trigger if you touch bottom or run over something mild.

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JCL · #2 10-17-2008, 01:18 AM

A few thoughts:

1) I can imagine that the airbag deployment was unexpected and unwelcome. It certainly appears to be expensive.

2) 25 degrees is a 47% slope by my calculation. That is approximately four times as steep as an extremely steep public road. It is six times as steep as a very steep public road. It isn't what BMW would consider normal use, IMO. I expect that is the basis of their opinion that it is your responsibility, on top of the impact to the undercarriage. Undercarriage impact is a known cause of airbag deployment, not specific to BMW.

3) While the airbag sensor is a g-sensor, it is conceivable that it is affected by its orientation, ie when it is inclined it may trigger at a different g-level.

4) Airbags don't usually go off under 10 mph, but some have been reported to go off at 7 mph. Most airbag injuries are due to low-speed deployments, often unwanted deployments.

5) Brochures and advertisements aren't generally proof of what is considered normal use. Many advertisements have notes in the fine print similar to "closed course, professional driver, don't try this at home" or something to that effect.

6) I don't know what the 45 degree reference is in the manual, can you elaborate?

There is lots of info here:

http://answers.google.com/answers/th...39.html#answer

vinuneuro · #3 10-17-2008, 01:20 AM

If you were driving off-road (which it definitely sounds like you were), I think the warranty would be thrown out the window. I'm sure it's specified in the owner's manual. Sorry.

sgt.sweetchuck · #4 10-17-2008, 02:39 AM

13k ??? ouch.
Is that just to replace one or all?

peacemf · #5 10-17-2008, 03:11 AM

where in the manual does it say you can go off road?
there isnt any clearance angles in the manuals! (compared to the RRS for example).

sorry but its true!
but 13k is a little steep! doesnt insurance cover it?

Marko · #6 10-17-2008, 03:39 AM

JCL, thanks for the links. 25 degrees was my guess at the incline but it was less steep than I have seen in the BMW offroad video they gave me when I purchased the car. Also check these stills from BMW Australia's website and a shot of the slope I was on.

The manual has a whole section about driving off road, which includes "the car can handle ascents and descents at gradients of up to 50%." It also says to "be aware that the car's underbody may make contact with the surface." No suggestion the airbags will go off! And in any case that's why there is a protection plate there.

peaceMF & sweetchuck, the $13K is for passenger front door, passenger rear door and head, and the passenger side curtain. So I figure if the whole set went off it would be about $33k! Of course I am insured but the fact is they shouldn't trigger in such circumstances - i.e. a very low speed, mild impact from below.

Hey I know it's not a Defender or a Landcruiser, but I don't expect the airbags to go off unless I crash the thing.

weirluo · #7 10-17-2008, 07:52 AM

disappointing result from X5. I have a X5 MY05 sports 3.0D. I know X5 is not designed as a off road monster,but it should handle some light off road duty. This is in Australia, lol. Otherwise I would go for a 530i.

From what I can see in the picture, my previous Subaru Forester would handle it without any problem as I used to take it off road to yarra ranges in vic. I have yet to take the X5 off road, but planing to do some sand driving over the Melbourne cup holiday. It's horrible to think the airbag has a possibility to deploy in such situation. Maybe I should think twice before joining another off-road trip.

Marko, was the passenger seriously injured? Lucky there was no kid in the car. I reckon BMW should not only be responsible for the repair/medical costs but it should offer a proper solution to such issues to all other car owners. But it's always hard to make them admit a product fault. I can only hope it's an isolated case. Lets hope...

weirluo · #8 10-17-2008, 07:58 AM

by the way, Marko, from my off road experience, it was possible to avoid the contact with a rock on that slope. if taking another path was not possible, which was according to the picture, I would rather ride the tyre on the rock rather than the bottom. In addition, one thing we all have to learn before taking our car off road is to get a real feeling of how high the bottom is so that we have the "feeling" before taking on any uneven slopes with rocks. Just my 2 cents.

JustinR · #9 10-17-2008, 08:53 AM

The only problem with using the tire is that it's going to crash down on the rocker panels instead of hitting the crossmember. That will cause more damage.

I can't believe the air bags would deploy by hitting the crossmember. Was the impact great enough to toss the passenger around?

Imagine if you were cruising down the highway at 70mph and a brick was kicked up into the crossmember. Are the air bags going to deploy and make you wreck?

Quote:

Originally Posted by weirluo

by the way, Marko, from my off road experience, it was possible to avoid the contact with a rock on that slope. if taking another path was not possible, which was according to the picture, I would rather ride the tyre on the rock rather than the bottom. In addition, one thing we all have to learn before taking our car off road is to get a real feeling of how high the bottom is so that we have the "feeling" before taking on any uneven slopes with rocks. Just my 2 cents.

Tominizer · #10 10-17-2008, 08:53 AM

Go up the tree on this with BMW. That's sounds like a huge load of CRAP. AND, you don't (or shouldn't have) said anything to them about what you were doing (off-roading)................. if it was me, I would have brought the vehicle back to the Stealership with a WTF look on my face.

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