Any air bag guru's out there?

I had a wreck the other day that should have triggered the steering wheel air bag. It never occured to me @ the time why the bag did not deploy until someone asked why it didn't go off.

Never has been any codes air bag related & the car had been running perfectly.

I'm curious as to why & would like to explore the reason why. Looking for a logical approach & don't understand how the system works.

Tx's

 

What was the speed you were traveling when the accident occurred? That may have played a part.

Did you check for any fuse being blown? Check fuse #16 in the fuse panel under the passenger side instrument panel under the toe-board.

Guess that the air bag wire harness connectors in the steering column are fairly sensitive; maybe that would be a reason.

 

I will check the fuse for sure, would you know if a deploy code would be stored?

Makes sense the mph would involved, highway speed I'm sure the airbag would have been commanded.

In the cars younger years column lock issue's reared their ugly head. I finally disabled thru HPT & removed the column lock kit. It's so long ago I don't remember what was apart & messed with. Potentially a steering harness finger trouble with that!

Tx's for the comments.

 

Please describe the collision events further.

If your Airbag warning light was not on then the system was fully functional.

 

Where was the car hit - direct frontal or off center/side hit?

 

No airbag warning light....ever.

The front impact was strong enough to break the engine cradle & push the front frame ahead of cradle to the left aprrox. 12". Hood is buckled , Rad & AC condenser destroyed, bumper & fenders including inner fender junk.

If the system was functional as suggested by no warning light where would I look for a problem?

 

Impact was directly in between the frame rails.

 

Are you the original owner?

Do you know if the car has ever been in an accident before?

It is legal to remove (or disable) the airbag in your vehicle and still sell it in the U.S., but it must be disclosed. I don't however believe an insurance company would have authorized a repair in the past that didn't restore the SRS to its pre-mishap status.

You will probably need someone with a Tech II to read the computers to see if it was disabled or possibly why it didn't deploy without giving you some indication it was out of commission. The computer actually performs a diagnostic on startup to check all of the sensors and verify all is well.

Good luck... GUSTO

 

GUSTO, I'm not the original owner nor do I know if a previous accident occurred. I doubt the car had been hit before as I'm **** beyond!

I'm very comfortable with HP Tuner, no Tech II, anything I may see?

 

If you are going to be repairing the car, I would make the fact that the air bag didn't deploy a major topic of discussion with the body shop. It is possible that someone had disabled the SRS light, but I suspect it would set a code. Have you pulled the codes with the DIC.

It will be too convenient to simply repair the car without investigating why it didn't deploy. Repairs will certainly be cheaper than if it had deployed. Your insurance adjuster may provide some insight about it. But if they don't look for a problem they certainly won't find one.

We had a Tahoe customer that hit a deer and tore up the front of her SUV. I was very surprised it didn't deploy the drivers air bag. It did keep the ins company from totaling the SUV. I asked the customer about it and she reported that her SRS light had been on for a while. It turned out she had a bad sensor on the front radiator support. We don't know if that didn't allow it to deploy or if it was just the hit. After repairs we replaced the sensor and were able to clear the SRS code.

GUSTO

 

Tx's GUSTO, I don't believe the car is repairable nor would I want to repair it.

This air bag thing is for my own information as to why it did not deploy, is it something I've done or someone else. I've a habit of modifying & working on things, this car was out of hands in a shop for several months for mechanical work. That involved dropping the drive line out.

Trying to avoid another mistake if that is what caused the issue. The other thing is you hear so much on the news these days about ignition switches & air bags I would like to rule that out.

I've not looked @ the DIC codes, HPT scanner has the ability to read codes & nothing has ever come up. My next step will be to look @ the DIC.

 

This does not describe the collision events. What did you hit? At what speed and direction?

Collision damage alone is not sufficient to determine Airbag deployment. I have seen hundreds of cars without deployment and significant damage.

From what you described the structure of the vehicle that is designed to take the impact energy did what it was supposed to do. Buckling a fiberglass hood and fenders, and all the aluminum bits behind it is a very easy thing to do.

 

this

 

My wife was recently involved in a wreck where she was hit from behind, and driven into the car in front of her. The damage to our car, a 2012 Jaguar XJ-L, was in excess of $36,000, and the car was totaled, yet the airbag did not deploy..........

 

In almost all newer systems, not sure exactly what year things were changed from early to later systems but, with todays systems there are some complicated formulas that determine when an air bag gets deployed in a frontal or near frontal collision, but in simple terms, (as I'm a simple man) rate of deceleration in a crash is what determines when an air bag is deployed, not the amount of damage. And those formulas very depending on type and strength of said vechicle structure. Don't hold me to these exact figures, this is just an example but if you hit a concrete wall at 20mph your rate of deceleration will set off an air bag, but if you hit a vehicle traveling in the same direction, although you may be going faster than 20mph your rate of deceleration won't be as significant. There by may not set air bag off. Another example would be if you hit a road sigh on a small pole or 4x4 timber might not set off bag as you will knock those down or they will break away, where a tree with a diameter similiar to a 4x4 post will not move or break and will create a faster rate of decel and the air bag will deploy.
Hope this helps, alot of info on this on the net, just google it. Asfor your car not deploying the air bag doesn't mean the system was malfunctioning, instead depending on the circumstances of the accident it may have function as designed.

 

Thank you for the input & comments

I will do the internet search thing & see what comes.