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Airbag deployment

jeppesen.io

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The JL will be my first off-road vehicle with airbags. Is there some way to prevent them from going off if you hit the steel bumper on a rock or something?

I honestly never really thought about it until now - what's the trigger threshold? I see lots of JKs off-roading, so I can't be that big of a deal.



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Billy

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The airbags are switched off when in 4lo (IIRC). Plus there has been no chatter about deployment when running trail, so I'd guess the threshold has been engineered to handle low Gs without deploying.
 

The Great Grape Ape

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Yep, after doing this many times myself, was curious as to why, I was also told that they are off at low speed too (IIRC under ~25KPH/15MPH).

PS, without having thought about it the first time in my old Sahara years ago was a rutt that looked like a puddle that I couldn’t attack at an angle, and bang head on into the ground (even dented bumper) was wincing for deployment, did that again with the Rubi in Glacier park a few years later, D’Oh!
 
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Low speed airbag deployment hasn't been a thing since probably the 70s. Airbags don't go off unless you actually need them, or around a 30-40mph impact. Airbag deployment is based on the impact sensed by the computer.
 

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Low speed airbag deployment hasn't been a thing since probably the 70s. Airbags don't go off unless you actually need them, or around a 30-40mph impact. Airbag deployment is based on the impact sensed by the computer.
There must be more engineering involved. Although maybe the front and rear crash sensors may be disabled in 4LO, over the summer an FJ rolled while climbing The Wall on Poughkeepsie Gulch in Colorado and its airbags deployed. So certain conditions may be able to be met to have them go off, unless Toyota just does something totally different than Jeep.
 

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an FJ rolled while climbing The Wall on Poughkeepsie Gulch in Colorado and its airbags deployed
I see no down-side to this.
 

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There must be more engineering involved. Although maybe the front and rear crash sensors may be disabled in 4LO, over the summer an FJ rolled while climbing The Wall on Poughkeepsie Gulch in Colorado and its airbags deployed. So certain conditions may be able to be met to have them go off, unless Toyota just does something totally different than Jeep.
There is a roll-over setup to the sensors (to cut-off fuel pump for one), so that may be involved where the roll-over event takes priority and deploys airbags. Just a guess though.

That being said said, my (low speed to me) t-bone wasn’t enough of a ‘tip-over’ event to deploy airbags.
 

AZCrawl

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There is a roll-over setup to the sensors (to cut-off fuel pump for one), so that may be involved where the roll-over event takes priority and deploys airbags. Just a guess though.
Yeah, that is the same line of thinking I had.
 

ERAUGrad04

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The JL will be my first off-road vehicle with airbags. Is there some way to prevent them from going off if you hit the steel bumper on a rock or something?

I honestly never really thought about it until now - what's the trigger threshold? I see lots of JKs off-roading, so I can't be that big of a deal.
Airbags are NOT disabled in 4LO. Recently on a trip to Moab, had a friend hammer down on Rocker Knocker and his driver side, side airbag deployed! To be fair, he came down HARD on his slider. I'll see if I can find the video.

That said, my last Jeep was a 14 Rubicon and I had some incredibly hard hits on trails in Moab, the Rubicon and Fordyce, and never had an issue with the airbags.

Also, airbag deployment requires quite a bit to line up for them to actually fire. They are activated by acceleration in a given plane. So a low speed rollover would not trigger an airbag deployment, no where near the acceleration threshold. The systems these days behind the safety features are rather advanced and smart.

Hope this helps!
 
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jeppesen.io

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Airbags are NOT disabled in 4LO. Recently on a trip to Moab, had a friend hammer down on Rocker Knocker and his driver side, side airbag deployed! To be fair, he came down HARD on his slider. I'll see if I can find the video.

That said, my last Jeep was a 14 Rubicon and I had some incredibly hard hits on trails in Moab, the Rubicon and Fordyce, and never had an issue with the airbags.

Also, airbag deployment requires quite a bit to line up for them to actually fire. They are activated by acceleration in a given plane. So a low speed rollover would not trigger an airbag deployment, no where near the acceleration threshold. The systems these days behind the safety features are rather advanced and smart.

Hope this helps!
Sure does! Thank you!
 

Billy

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The only downside is it totals the vehicle, but safety first.
I'm guessing the roll over itself will total the vehicle.
 
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There must be more engineering involved. Although maybe the front and rear crash sensors may be disabled in 4LO, over the summer an FJ rolled while climbing The Wall on Poughkeepsie Gulch in Colorado and its airbags deployed. So certain conditions may be able to be met to have them go off, unless Toyota just does something totally different than Jeep.
The engineering involved has to do with the requirements of the G-sensors. I only listed the speed as a reference of hitting a brick wall or a tree, but there is a G-limit. You accelerate at 8m/s/s. So in a 2 second free-fall, you're falling fast enough in a vehicle to warrant the airbags going off. In a 3 second free fall you're going highway speed. A roll over will also change the angle the G-sensors feel the hit, the same reason why a side impact will not usually set off the steering wheel airbag.

I have never heard of airbags being disabled no matter what driving mode you're in. The only thing that shuts off in 4 low on a JK is the traction control, but even then the BLD system is still active.
 

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