Armor FR bumpers & active airbags (srs) - who had gambled & lost / Blown the bags?

[LINUS]

So I was randomly daydreaming in traffic today & the title of this thread came to mind - and so the question to you all:

Who here ignored the ARB (or any aftermarket bumper I suppose) where there was that little sticker that told us all to DE-activate the airbag/SRS because the bumper would transmit more G's to the impact gauge & blow the bags - and by ignoring the sticker had the bags blow while out wheeling?

I had thrown the SRS fault light not to long after installing the ARB up front (cough, cough ~2002), so I just sidelined worry over the issue - then last Spring while doing my axle service/lockers/regear/winch install, I finally reset the light (yes, ~9 yrs later) & reactivated the SRS system.

So then while in traffic I gave more thought than just the normal "at least my airbags work again" - and realized I've done a few mildly fun / equipment wearing type things since getting the airbags active again & realized maybe I'd be in danger of a not-so-cool face rash & the crazy headache that airbags give if I don't install some sort of cutout switch for trail running that I can then re-arm for street driving (the only time I want SRS on in my mind).

So I ask, has anybody here popped the bags while out on a trail just because you landed/scraped a good size rock that the SRS decided was airbag worthy?

I thought this might be a good talking point anyhow as we are seeing a lot of guys building some real nice bumpers lately who, without the sticker - may not have really thought the issue through or know what the possibilities of a good "thump" might do / not do.

Sorry if this has been talked about recently, I might have 'missed class' that day.

 

[Hoosier Daddy]

FWIW, I had a slightly offset (30 degrees off?) head-on with a Durango in my last ARB-equipped 80, at moderately low speed (middle of intersection). The 80 was able to drive away but the Durango had its engine pushed into the firewall. I had active airbags, but they didn't go off.

Had a TJM on my old Tacoma and rear-ended an Olds Delta 88 hard enough to completely compress the car's trunk and total it. TJM was unscathed and the airbags did not deploy.

I realize your question is about vehicle vs terrain off road, but based only on my experience I'd guess the airbags won't go off unless really needed.

 

[NLXTACY]

FWIW there aren't impact sensors on the bumpers. There is an inertia (?) switch located under the console that senses the extreme sudden deceleration thus activating airbags.

...or something like that

 

[BrotherRob]

Never seen nor heard of an airbag deploying while wheeling (including one rollover).

As I understand the warning, it just means that the bumper manufacturers didn't bother to test the airbags with the bumper, so they had to add the warning. I see no reason to believe that the airbags are more or less likely to deploy with an aftermarket bumper. From what I've seen from the reports on 'Mud on auto accidents, it takes a pretty good jolt to deploy the bags, which is how they were designed.

 

[lndcruz]

FWIW there aren't impact sensors on the bumpers. There is an inertia (?) switch located under the console that senses the extreme sudden deceleration thus activating airbags.

...or something like that

This. The 80s SRS system is not very complex in its sensors say compared to a modern car with multiple airbags.

I was under the impression that a ARB or other aftermarket bumper would delay the airbag from being deployed or cause them to not deploy at all.

 

[jeffro109]

Any delay would not be very long, fractions of a second in a severe accident. The 80 series has the acceleration (or deceleration as it would be) sensor that trips the bags. There is probably some effect of an ARB or other bumper not absorbing as much of the impact and passing it on to the truck or whatever you ran into, but you are still decelerating pretty quick on the whole.

Newer designs with side air bags, etc that go off for various reasons including a side tip, are more prone to the offroad activation.

If you nose-dive off a ledge and hit hard dirt, you might set it off??

 

[LINUS]

Never seen nor heard of an airbag deploying while wheeling (including one rollover).

As I understand the warning, it just means that the bumper manufacturers didn't bother to test the airbags with the bumper, so they had to add the warning. I see no reason to believe that the airbags are more or less likely to deploy with an aftermarket bumper. From what I've seen from the reports on 'Mud on auto accidents, it takes a pretty good jolt to deploy the bags, which is how they were designed.

If what you get from the warning sticker is what the majority here have understood it to mean, then that makes sense.
I've had most parts of my 80 open at some point or another & IIRC the sensor was something I saw ahead of the dash on the center tunnel & I think it was some simple ball that if inertia pushed it forward would trip.

Not only that, but I personally think the OEM bumper & a ARB (or any) bumper would essentially transmit the same force to the trip sensor - the OE is just pretty channel iron bolted to the front frame horns, and the ARB does exactly that too. It's not like the OE bumper has impact foam or shock absorbers that we deleted adding the aftermarket bumpers -- we really just traded the shape of the channel iron we bolted to the frame using the same bolt holes -- at least that's how I see it.

I just wanted to make sure that it wasn't something of common knowledge to kill the bags when really offroad & catching little jolts etc, especially the kind that might be transmitted by a direct rock to frame type "thump".

Really - it's bad enough if you leave a big ol' dent up front, but to add insult to injury like having the bags go off to really announce "Hey, look how big of a dummy I am guys!" - that would just be a little too much, let alone the ride home without side windows & fishing tempered glass slivers out of your butt the whole next week each time you sit in the seat. Just a whole bag of "no fun to me" I'm trying to avoid.

If some of the more experienced guys with more rock time than myself haven't tripped the bags, then I doubt my sissy butt will - I suppose I could just ask Christo & see what his experience is, if he hasn't popped a bag then I doubt many others would have either

 

[Nay]

Generally speaking, it would be difficult to to deploy the airbags in slow speed wheeling/rock crawling. I have never hit anything offroad at remotely the impact you would see in a 5 mph fender bender, and those accidents don't generally deploy the airbags. I have never seen anybody in any vehicle deploy an airbag as the common accident is a roll, not a front end impact.

I see it fairly simply - if my airbags ever deploy offroad, it will be because I needed them, and chances are pretty good that the rig is not getting back out under its own power at that point.

 

[Jacket]

Just as a further data point - the newer Tacomas (and maybe other Toyota 4x4's) now include a deactivation switch to turn off the side curtain air bags. But they have nothing to disable the front bags. I don't know how the side curtain bags work, and if it is different than the front air bags, but I think I remember reading that one theory is that the side curtains could be triggered in an off camber situation.

The after market bumper folks just need to include the air bag disclaimer to defend and protect themselves.

 

[ardentyota]

When in 4lo, the airbags are deactivated.

 

[timer00]

Just trade in for a pre-95 model

 

[LINUS]

When in 4lo, the airbags are deactivated.

Really? This is a point I'd never heard of before.

In that vein then, I wonder if the "pin 7" mod means the bags are off anytime you use your CDL switch?

 

[ardentyota]

CDL and Pin 7 are two different things. CDL lock does not turn off the airbags but 4low does. It's in the owner's manual and the airbag light turns on when in Low.

 

[LINUS]

CDL and Pin 7 are two different things. CDL lock does not turn off the airbags but 4low does. It's in the owner's manual and the airbag light turns on when in Low.

I'll go doublecheck when I run to town, but after doing the pin 7 mod I get the ABS, the CDL, and I know 1 more (SRS would fit) - I'll just really go do it, but it seemed that to me by doing the pin 7 that when you hit the CDL button was now the driver & whichever position you were in on the trans case was immaterial.

I'll go run it, but that's what I swear I see going on.

Just so we're clear - if the airbag light is on, they aren't working - correct?

 

[Impreza]

CDL and Pin 7 are two different things. CDL lock does not turn off the airbags but 4low does. It's in the owner's manual and the airbag light turns on when in Low.

My 1996 def does not show airbag light in 4L.

 

[lndcruz]

Nor does my 95. Only ABS and CDL

 

[BrotherRob]

When in 4lo, the airbags are deactivated.

I've never heard this either. It's kind of a moot point though. In 4lo, you are unlikely to be going fast enough to deploy the airbags.

 

[86tuning]

CDL and Pin 7 are two different things. CDL lock does not turn off the airbags but 4low does. It's in the owner's manual and the airbag light turns on when in Low.

Are you confusing ABS with SRS?

 

[ToyotaDon]

Just as a further data point - the newer Tacomas (and maybe other Toyota 4x4's) now include a deactivation switch to turn off the side curtain air bags. But they have nothing to disable the front bags. I don't know how the side curtain bags work, and if it is different than the front air bags, but I think I remember reading that one theory is that the side curtains could be triggered in an off camber situation.

The after market bumper folks just need to include the air bag disclaimer to defend and protect themselves.

To clarify, these are Roll Sensing Curtain Airbags designed to deploy in the event of a rollover. Yes, an off-camber situation could also set them off, hence the switch to disable.

When in 4lo, the airbags are deactivated.

Not finding anything about this in the owner's manual, pretty sure you're thinking of ABS.

What I did find in the owner's manual was this info:

The SRS airbags will deploy if the severity
of the impact is above the designed
threshold level, comparable to an approximate
20 km/h (14 mph) collision when impacting
straight into a fixed barrier that
does not move or deform.
If the severity of the impact is below the
above threshold level, the SRS airbags
may not deploy.

 

[ardentyota]

Crap. I know I read that somewhere in the manual, but can't find it. I remember telling the wife about it so she wouldn't worry about the airbags while wheelin'.

Sorry if that was bad info. Maybe it was on a different vehicle.