issai

My friend's 05 tC was involved in a moderate speed collision yesterday. One aspect of the collision that has stumped him and me is that none of his airbags deployed. He was third (from behind) in a rear-end collision chain, where he was slowing down at 15mph, whereas the person causing the accident was going 60 mph.

I didn't have a chance to snap photos of the damaged areas, but I'll try my best to describe it:

There was major intrusion into body panel and frame in the rear left corner of the car. Frame / body panels were crumpled in to the point where I can tell that the car that hit him from behind was stopped by his left rear tire. Rear crumple zone was crushed, bumper has completely fallen off, trunk lip and some of the trunk compartment was crumpled inward and upward (but the force was eventually absorbed by his spare tire-- passenger cabin was not intruded). Control and trailing arms, rear axle all appear intact and unintruded.

There was major intrusion into the left front section of the engine compartment, stopped, again, only by the front left tire. The crumpling was as far inward as his battery, as the front half of his battery is cracked open. Anything forward of the battery was destroyed (radiator, fusebox, etc.). Passenger compartment wasn't compromised.

Mechanically, I don't know the tC at all, but we were shown where the airbag sensors were located by the body shop who tends to fleet cars for Denso and Toyota Motor Sales NA HQ (where the car is currently stored). It appears at least one of these sensors was openly visible because the front-left engine compartment's corner was curled inward and upward, revealing it.

What we're wondering is how come the car's accelerometer did not deploy any of the airbags. Judging by the amount of damage alone, the force seems sufficient to deploy them. My friend's head didn't hit the steering wheel, however, so maybe they do deploy, but at a much higher, aggressive decceleration threshold?

I've experienced a side collision before in my BMW with far less resultant damage (wheel, trailing arm, control arm, other misc. suspension components), and with apparently far lesser force, but still my curtain airbags did deploy.

Thanks in advance for any insight.

titolito

Unfortunately, I wrecked my tC yesterday. I was hit at an angle by a car doing about 40 MPH. I found what was left of my bettery up against the firewall. I don't know where the airbag sensors are, but my airbags did not go off either.





The weird thing is, it didn't FEEL that bad from inside the car. The only reason I knew it was bad was because I watch in slow motion as the front end of my baby was accordioned into the windshield. I don't know if the airbags were SUPPOSED to deploy, but I know I felt totally safe inside the car as the crash occured. I walked away with only my feeling hurt.

engifineer

ahhhhhh this has been discussed a million times.. no offense.. but it has.

Sounds to me like they did thier job. They dont just go off from getting hit in a certain spot. They are ACCELEROMETERS. This means that it takes a rapid decelleration in the right direction to cause them to go off. Airbags should never go off in a rear end colliision to start with unless you are pushed into something in the front hard enough to warrant them. And regardless of the direction of the impact, the car has to decellerate (or accelerate in the right direction if from the side) at a rate high enough to warrant the airbags to deploy. If the occupants did not slam into the steering wheel or side of the car violently, that is a pretty good indication that they should not have deployed.

When airbags first came out, many companies were in some deep poo because of airbags that deployed when they should not have, causing serious injury (an airbag hitting you in the face in a minor collision can mess you up) or a worse wreck because the airbag caused the driver to lose control of the car and further crash into something else.

The fact that both your friend and the other person posting here are unscathed is a good indication that the car did just what it should have.

paul34

While I understand your concern, the amount of damage a car takes is (usually) not a good way to judge whether the airbags should have gone off. Modern cars are built to crumple like a tin can, with some cars being worse than others (Civic DX, anyone?).

The airbag is there to prevent you from hitting your head on the steering wheel - it would seem that the collision your friend was involved was not severe enough for this to happen, so airbags were probably not needed in this scenario.

Glad your friend is ok, though. And if it had been that bad of a wreck, I'm sure the airbags would have gone off. I think your friend is better off for the airbags not going off... that thing can cause injuries of its own.

Again, glad you both are ok. Be careful out there everyone! These types of threads always make me a little scared of someone hitting me or me otherwise getting into an accident...

issai

I apologize for the "repost."

I did a search with various terms, and the # of results returned were immense. Would've taken me significantly longer to sift and pick for my answer, vs. simply posting it again.

issai

titolito-- sorry about your loss. Hope you're physically OK. My friend's tC looked exactly like yours! (except his had that metallic, dark slate ext. color).

Thankfully, I wasn't in the car with my friend. Unfortunately, he's experiencing some pain, though.

Thanks for the airbag explanations, all. After mulling over my thoughts for a bit, and right while I was writing up the OP, it's what I thought the answer would be.

Viscerally, though, I still find it ironic that the collision was forceful enough to almost rip off the accelerometer / sensor needed to deploy the airbags.

Budsmoke

Large dents in the car don’t indicate that the airbags should have deployed. Large dent in the skull indicates a malfunction.