So I’m writing a thriller that features a car chase scene. The driver of the car knows it’s likely to get rough, so he needs to get rid of the airbag the night before the chase. How would he do this?
Is this easier (or safer) than just removing the airbag? I mean, it’s pretty cool, so I’d like to include it in the novel, but if just removing the airbag (after disconnecting the battery) would be so easy that the actual deploy option is dumb, then maybe I should have my character just remove the airbag without setting it off.
I’m not sure about the actual process, but one thing to think about is whether or not removing an airbag is legal. Iirc there are “tampering” laws related to removing certain parts from cars in the US and possibly other countries. E.g. if it were legal, the protagonist could probably get a local garage to do it. If illegal, not so easy and might require some more underhanded dealings.
Also, I thought that when an air bag deploys it makes the vehicle inoperable?
So just removing the air bag might not be enough. While it would keep the bag from exploding in your face while racing along, the engine might still get shut down. That is, the collision detector that triggers the air bag might need to be bypassed as well so that a collision wouldn’t stop the vehicle.
I could very well be wrong about it, so hopefully someone in the know could speak to that.
But it might be another detail you could add to lend authenticity to the narrative.
A quick search reveals that some vehicles do have engine shut down features either via the fuel pump or a small explosive device of some kind to disconnect the battery to reduce the risk of fire.
I don’t know though whether the collision detector sets off the air bag and the other devices or if it’s the air bag deploying that sets off the other devices.
However, I did see one story of a guy driving down the road and his side airbags went off for no reason and he was able to keep driving.
Anyhow, something for you to look into if it sounds interesting.
Removing the driver’s airbag is generally fairly quick and easy. It might be more work to remove the passenger’s bag, but I’d still do that over deploying it, which makes a mess and on some models rips open the dash.
::: shrug:::
As has been mentioned a deployment can cause engine shut down, that is not the 600Lb gorilla in the room.
If the airbag deployed that means your character had an accident. Cars that have been in accidents often don’t drive well, or at all for that matter.
Also which bag(s) are you disconnecting? Driver’s? Passenger’s? Side impact bags in the seat? Curtain bags from the headliner?
What kind of accident is our hero having?
As far as disconnection goes, key off unbolt (or release) the bag from it’s mounting in the steering wheel and disconnect the electrical connector(s).
The passenger bags is often more difficult as the bag is often under the surface of the dashboard.
If you want to disconnect the airbag module it is probably in the center console or under a front seat. I’ve never seen one under a dash.
Hope this helps.
I would have thought that pulling the connector off the ECU (probably under the seat) would do the trick. A mechanic must have a way of making it safe to work on.
I note that an airbag will not go off for the passenger seat if there is no weight on the seat. At least in my Nissan. There is a warning light on the dash to let you know that the passenger airbag is not armed.
So there is a weight sensor for the passenger side. I doubt the driver side has such a sensor… but…
So the question for the OP is the protagonist removing them stealthfully or not?
One thing that might-in theory-work is if the car is an automatic, have the Protag turn the car on, put it in drive, and while it’s moving, whack the exact spot of the airbag sensor with a sledgehammer. (Different cars have different sensor spots).
Otherwise, if you GIS stolen airbag, you can just see where the hole is now on a steering wheel.
Both of those are going to show evidence where it’s been tampered with. Although, I would reckon with the second, the Protag could get a steering wheel cover.
Part of the problem with the whole premise of the thread is that this isn’t how airbags work. There are impact sensors, but the computer only uses them to determine what kind of collision (front end, side, etc). To actually deploy the airbags, it relies entirely on inertial sensors. The amount of deceleration required for the computer to fire the airbags is WAY more than the brakes are capable of delivering. Even tradin’ paint in a car chase won’t do it unless, you know, you actually crash.
But, to actually answer the OP, finding the inertial sensor(s) and just unplugging it will prevent the computer from deploying the airbag (and illuminate the SRS or Airbag dash light.) There shouldn’t be any need to physically remove the airbags.
Also note that for the passenger airbag, some cars have a switch by which you can manually disable the passenger airbag (in case you want to put a child seat in the front) rather than a weight sensor. A weight sensor would never be put in the driver’s side because there is no practical way of driving the car without someone in the driver’s seat, so such a sensor would be redundant. To put it another way - if the car is moving, the driver’s airbag should always be armed.
This is from memory so my apologies if I get something wrong:
GM cars, at least back when I worked on them in the late 90’s, used 3 inertia switches. 2 of the 3 switches had to indicate a collision for the airbags to deploy. The inertia switch needed a deceleration comparable to driving into a solid wall at a speed of at at least 14 mph. That’s a pretty serious whack!
Fords from the 90’s and 00’s (maybe even now?) had an inertia switch in the trunk that disabled the fuel pump after a crash. I remember reading about criminals being chased by police in Ford Crown Victorias would hit their brakes hard, making the police car hit them and set off the inertia switch. I think Ford had to change the switch in police spec cars after that?
Easiest way to disable the airbag is pulling the fuse. If that fuse powers something else that you need, you can just unplug the airbag. Or if you don’t have time to find the wire connector you can just remove the whole thing from the steering wheel.
I only just noticed that, and it’s because we had a baby and my wife explained to me that’s why it was there. If there’s nothing on the passenger side, in my car, though, there is no “passenger airbag not armed” light. But once there’s a certain range of weight on it, it comes on. Anything heavier than a certain amount, and it goes off again. I always wondered what the hell was wrong with my car, as I used to put camera gear on the passenger seat, and sometimes the passenger airbag light would be on, and sometimes off. I only just recently realized it was because it was just on the cusp of whatever threshold there is for that sensor. It didn’t even occur to me that there was a sensor on the passenger seat. I just assumed my car’s passenger airbag was flaky.