Do airbags activate if you aren't wearing your seatbelt?

**jatcos** · November 23rd, 2008 01:49 PM

May i just butt it mga boss, curious din kasi ako..

Maybe marv25s question is related to the algorithm car manufacturer set on ECU..Based from my research, airbag deployment/ threshold is a function of overall vehicle design. Common vehicle safety design decides when to deploy airbag given the following conditions:
1. if front driver/ passenger is belted
2. acceleromometer senses deceleration to a 23 km/h barrier collision (US, dont know whats global standard)
3. if front seats senses a load(occupant)

It seems that most vehicles sold here deploy airbag if it satisfies condition number 2 only..Tama ba?? Kaya wether belted or unbelted, sure deployed airbag nun. My question is.. will it deploy if ignition key is not present, not set to on or acc, engine not running? Say for example car parked encountered parking brake problem and accidentally fell in a ravine nose first.. Deploy kaya airbag nun??

**v6dreamer** · November 23rd, 2008 02:45 PM

Originally Posted by jatcos

May i just butt it mga boss, curious din kasi ako..

Maybe marv25s question is related to the algorithm car manufacturer set on ECU..Based from my research, airbag deployment/ threshold is a function of overall vehicle design. Common vehicle safety design decides when to deploy airbag given the following conditions:
1. if front driver/ passenger is belted
2. acceleromometer senses deceleration to a 23 km/h barrier collision (US, dont know whats global standard)
3. if front seats senses a load(occupant)

It seems that most vehicles sold here deploy airbag if it satisfies condition number 2 only..Tama ba?? Kaya wether belted or unbelted, sure deployed airbag nun. My question is.. will it deploy if ignition key is not present, not set to on or acc, engine not running? Say for example car parked encountered parking brake problem and accidentally fell in a ravine nose first.. Deploy kaya airbag nun??

No, airbag operate on a electronic circuit and active only when the ignition is on.
If no power is being sent to the SRS computer everything is off.

**mbeige** · November 23rd, 2008 03:20 PM

Originally Posted by marv25

ok fine. sorry na nga. pls close this thread. thanks.

That was for your own sake.

**jatcos** · November 23rd, 2008 05:05 PM

No, airbag operate on a electronic circuit and active only when the ignition is on.
If no power is being sent to the SRS computer everything is off.

Hehe..oonga pala, airbag ecu is active only when engine is running..

So to answer marv25 - other cars depende sa design would not inflate airbag if it detected an unbelted passenger/driver, but most likely kung philippine model ang car, it would inflate basta may 23km/h deceleration..

**marv25** · November 23rd, 2008 05:31 PM

sorry ha but i mean... i can be convinced to wear a seatbelt easily... but redorange didnt sound like he was trying to convince me... more like reprimanding me...

**CVT** · November 23rd, 2008 05:52 PM

^^^ No need for that bro.,- I would strongly recommend wearing your seatbelt, all the time. It's our primary line for safety when riding in a vehicle.....

7000:diver:

**jatcos** · November 23rd, 2008 05:53 PM

Maybe because you sounded like wearing seatbelt is not of big importance wherein some people may get irritated with that idea. Katulad ko when oldies ang passenger or even my mom, hindi sila nag sseatbelt kesyo short distance lang daw ang travel kaya i ended up na pinapagalitan ko sila..Icipin monalang concerned lang sila kasi life isnt worth with that negligence..hindi din nagkulang ang owners manual on how to operate the machine safely..hehe..always buckle up..

peace po mga bossing.

**marv25** · November 23rd, 2008 05:56 PM

yeah i do wear the seatbelt sometimes. coz theres this buzzer thing that wont stop beeping every 300m if i dont put it on. Now just to make it a habit to wear it all the time regardless of the car.

**niky** · November 24th, 2008 10:43 AM

It's just that not wearing your seatbelt in an airbag equipped car at slow speeds is actually more dangerous than actually putting it on. Even a very slow "hit" can set off the airbags, and they're not programmed to know whether your face is two feet from the dashboard or two inches.

Don't fret about it... we were all newbie drivers at one time or another.

RE: airbag deployment:

In the US, sensors that detect whether the front passenger is a child or a small person are now mandatory, to prevent suffocation due to airbag deployment. With older airbags, the airbag will turn off. With new, two-stage airbags, the airbag can be inflated with less force, thus being safe for short passengers. You still can't put rear facing child seats in front, though.

**mbeige** · November 24th, 2008 12:45 PM

Originally Posted by niky

It's just that not wearing your seatbelt in an airbag equipped car at slow speeds is actually more dangerous than actually putting it on. Even a very slow "hit" can set off the airbags, and they're not programmed to know whether your face is two feet from the dashboard or two inches.

Don't fret about it... we were all newbie drivers at one time or another.

RE: airbag deployment:

In the US, sensors that detect whether the front passenger is a child or a small person are now mandatory, to prevent suffocation due to airbag deployment. With older airbags, the airbag will turn off. With new, two-stage airbags, the airbag can be inflated with less force, thus being safe for short passengers. You still can't put rear facing child seats in front, though.

The problem with that is some people have unique body physique. It's hard to determine the baseline numbers that activate an airbag, let alone one that has sensors to detect the weight of a person in the passenger seat. It could be that some person who's light weight may fool the sensor into thinking it's a child, when it's a small adult in reality. If an accident occurs and the air bag does not deploy and the person acquires injuries because of that, then we have a lawsuit.

Also, the position of the passengers in a crash also determines if they survive or not, or acquire severe injuries. Some cars just do with airbags and a seatbelt per front passenger, not taking into consideration pretensioners that pull the seatbelt firmly in order to pull the passenger closer to the seat, preventing him or her from hitting the airbag (or what is supposed to be there anyway) too soon. If you hit it too soon, you'll probably hit the dashboard, too late and the bag will have deflated.

Which brings me to my point, seatbelts are your primary line of defense. The airbags are SRS equipment - supplementary restraint systems designed to work on top of the seatbelts. One cannot rely on the airbags alone for safety.

Even if we're newbie drivers at one point, we should learn to be safe from the beginning. I cannot stress enough the necessity to wear seatbelts in case of an accident.

[ame="http://www.youtube.com/watch?v=dWZOzc-mb68"]YouTube - No seatbelt, bad news[/ame]