A good friend of mine recently wrecked his brand new 2008 F150 SuperCab 2WD truck. He hit a tree head on doing approx 25-30mph. He didnt have his seatbelt on but his passenger did. Hitting a tree head on at those speeds was enough to send him up over the steering wheel into the windshield w/ enough force to shatter the glass but not send him through it. It was also enough force to render the truck as a complete write off according to his ins co. Now here is the concern/ question... there was ZERO airbag deployment on either side of of the truck.

I simple cursory inquiry netted some responses form Ford guys along the lines of "Sometimes if you dont have your seatbelts on the bags wont deploy"...

I call BS on this concept. Esp since one belt was plugged in and the other was not... neither bag deployed. I know air bags are not designed to replace sealbelts but at the same time they are there to try to save lives in any situation that warrants thier deployment... Soooo can any of you fine folk here enlighten me as to what my next course of action/ inquiry could or should be? I'm just trying to get an idea of where to go... Thanks in advance for any information.

~RB

 

Don't crash into trees.

 

What exactly are you (he?) trying to find out? Just to find out why the airbags didn't go off? I noticed you mentioned that some Ford guys said "Sometimes if you dont have your seatbelts on the bags wont deploy." Is he trying to sue Ford? Just doesn't seem clear to me:
Next course of action for/to do what?

I guess the next question would be, why did he crash into a tree? Airbag or not, he should have just had the seatbelt on? That's what they are there for...

 

I agree!

 

air bags take 2 of the 3 sensors to deploy

two impact sensors up front, and the "safing" sensor in the cab that has to do with how fast of a decel is forced upon the driver/passenger

 

I agree with the RCM on this one.

 

Im pretty sure he had no intentions of hitting the tree. I cant answer why his seatbelt was unbuckled but in all reality thats not the point. Seatbelt on seatbelt off...in a full frontal collision at speeds that can create enough force to total the truck and send a 250 lb man into the glass and shatter it... it's my opinion that the airbags should have deployed. Sue Ford? Maybe. Im pretty sure in the eyes of the court... why he hit the tree and whether he was using a seatbelt or not will be of less concern rather than why the airbags didnt deploy. Unless of course as was mentioned in the only useful response here...there are series of events that need to happen that maybe this particular incident didnt create... in order to get deployment.

What am I trying to find out? I drive the same truck... although I wear my seatbelt every time I drive...if seatbelts were 100% failsafe I suppse we wouldnt need airbags now would we? But for some strange reason they are federally mandated in all motor vehicles now... Whats my point? If the F150 is prone to airbag malfunctions in any type of serious collision let alone a full frontal... THAN I DONT WANT IT.

I was hoping for relatively comprehensive information here. Responses like "Dont crash into trees" remind me why I have been a member of this site for 8 years and have only made 20 posts. Maybe he was swerving to avoid a child who ran out into the street. Einstein.

Thanks for the insight Patman! Much appreciated

~~RB

 

where did he hit the tree in relation to the vehicle? If he hit it dead on a frame rail (about halfway to the side of the truck) then he would have been more likely to trip the air bags vs if he hit it dead center in the truck.

The system would see the impact but would say that the decel isnt hard enough to deploy the bags. The system also gets wierd with "glancing blow" colisions etc that can be very violent, but not decel the vehicle "enough"

Remember the highway saftey comission does their offset collisions at 40mph, almost double what your friend was doing.
-Patrick

 

N2,it is a bad situation when the airbags don't deploy in an accident like this.I'm sure Suzuki was just kidding,not in a sarcastic way,but just to lighten up the situation.That was my intention with my reply anyway!

 

Patman- he hit pretty dead nuts on the driver side front of the truck. I know they have over the years upped the protocol/ conditions for deployment. I am more or less just trying to get an idea of what that process is these days. Thanks for taking the time to help!

Blue- I'm sure both of you were jsut keepin it light...it's just seems as if the 1st 3-4 responses were all facetous as to people sitting back and wondering how they would feel if if it was them...they may or may not have the same questions.

I got thick skin... Im just (obviously) not on the forum enough to know who cynics are. LOL no worries. Thanks to all.

~R

 

In all reality, if the airbag DID go off, he would probably have been hurt worse. Those things are extremely dangerous without having a seatbelt buckled. To be flying forward with that much force and then to have an airbag deploying with a huge amount of force in the opposite direction equals a really bad combination.

If anything, he is extremely lucky it didn't deploy IMHO.

Which is maybe why it didn't go off.....maybe there is a sensor that detects if a seatbelt is not buckled it won't deploy the bags???

 

JD- Turns out that are prolly correct. I found what I needed on another forum. For those that care to read here you go. Thanks again to all! all that were productive at least.

~RB

Props to BigS1975 over on YellowBullet for this one...

Safety Belt Buckle Switch
As part of the supplemental restraint system (SRS), the driver and front outboard passenger safety belt buckles are equipped with a Hall-effect switch. The safety belt buckle switches indicate to the restraints control module (RCM) whether the safety belt buckles are buckled or unbuckled.
The RCM uses this information in determining the deployment rate of the dual-stage driver and passenger air bag modules.
The safety belt buckle switches are also used for the driver safety belt warning system and the driver Belt Minder® and passenger Belt Minder® (if equipped). Refer to Section 501-20A and Section 413-01 or the Owner's Literature.
Safety Belt Pretensioners
As part of the supplemental restraints system (SRS), the safety belt buckles are equipped with pretensioners. The safety belt buckle pretensioners remove excess slack from the safety belt webbing. The pretensioners are activated by the restraints control module (RCM) when the module detects a frontal impact event exceeding a programmed limit and the safety belt is latched (buckled). The passenger safety belt pretensioner can deploy regardless of the presence of an occupant if the front outboard passenger safety belt is latched (buckled).
Principles of Operation
A supplemental restraint system (SRS) consists of a driver and passenger dual stage air bag module (containing an inflator/squib or gas generator and an air bag), safety belt pretensioners (containing an inflator/squib or gas generator), impact sensor, a restraints control module (RCM), a clockspring, an air bag warning indicator, occupant classification sensor (OCS) system and a passenger air bag deactivation (PAD) indicator. These components are all interconnected by a wiring harness and powered by the vehicle's battery. The RCM includes a backup power supply. This feature provides sufficient backup power to deploy the SRS components in the event that the ignition circuit is lost or damaged during impact. The backup power supply will deplete its stored energy approximately one minute after power and/or ground has been removed from the RCM. If a SRS fault exists, the RCM supplies a ground to flash a coded sequence which is called a LFC on the air bag warning indicator located in the instrument cluster (IC) module. Each LFC is flashed 5 times after which the air bag indictor will remain lit for the remainder of the key-on cycle. In addition to the self-test at start up, the RCM continuously monitors all of its external and internal circuitry for faults.
In a frontal collision, the impact sensor located in the front of the vehicle detects sudden deceleration and sends an electrical signal to the RCM. The RCM uses the information from the impact sensor in the deployment determination. If the RCM determines that deployment is required, the RCM sends voltage and current to the squib(s) causing the solid chemical propellant to undergo a rapid chemical reaction. This controlled reaction produces harmless nitrogen gas that fills the air bag(s) and/or activates the safety belt pretensioners to remove slack from the safety belt(s).
The RCM communicates through the data link connector (DLC) the current and historical DTCs
Because the driver and passenger front air bags each have 2 deployment stages, it is possible that Stage 1 has deployed and Stage 2 has not.
If a front air bag module has deployed, it is mandatory that the front air bag module be remotely deployed using the appropriate air bag disposal procedure.
For this vehicle line, the SRS uses one satellite sensor in addition to the RCM. The RCM is mounted to the center tunnel beneath the 20 percent seat or floor console (if equipped). All vehicles have one front impact severity sensor located in the front-center area of the vehicle, behind the grille mounted on the lower radiator support. Mounting orientation is critical for correct operation of all impact sensors.

 

Agree with JD790. Can't remember where I read this, but I believe with the early sensors, the air bag would go off even if the seat belt was not in use. It was found that this was worse than no air bag and no seat belt. for all I know, they may have it set up so that the air bag will not go off if the seat belt was not in use. Similar to it not going off on the passenger side if the passenger is under a certain weight. Also they have changed seat belts to not go off with too much force as they were killing people who would sit too close to the wheel. Minimum distance from the wheel is supposed to be about 10". I have sen many people sit much closer than that.

 

There is no hard/fast rule about airbag deployment. Sometimes they go, sometimes they don't. They're supplemental restraints, they're the last line of defense for when your *** is on the line and things are going bad in a big hurry. They tend to not deploy unless you really, really, really need them.

 

hope your friend is alright, other than that.. a lawsuit is not the answer..