Prius Airbag system

I thought that the definition of a dual stage airbag is to know the location of the passenger, but maybe I have this wrong...

I'm unsure if it senses the position of the seat. I should've looked when I had my passenger seat out....

As for the weight thing, it doesn't sense the amount of weight. Only that a certain amount of weight is required to let the system know that there is a passenger. A contact is made when the passenger sits down.

This is what the sensor looks like. This is looking at the seat bottom, just under the upholstery and from the rear of the seat looking forward...

Cheers,

 

The Prius detects the presence of a passenger AND the position of the seat. Thus, it will adjust the airbag parameters depending on the seat position.

Cheers
don r

 

It also detects the position of the driver seat to adjust airbag deployment intensity.

 

So, my salesperson told me that the passenger airbag would deactivate with a child in the front seat. I have heard of this in other vehicles, but in those there is usually and on/off indicator somewhere. She directed me to a page in the owners manual, but the only thing I see in the owners manual is "Toyota strongly recommends that all infants and children be placed in the rear seat of the vehicle"
She said that most Toyota's have this feature and was telling me a page to reference in the owners manual. Is this one of the options that I don't have? Just curious, obviously I am not putting my kids in the front seat, just would be good to know if it was at all safe to do so in a pinch.

 

RE: Children in the front seat...this is an important question. Naturally, they go, and belong in the back. However, all that begging to sit in the front on short trips sometimes wins me over. DanMan, do you know if the passenger bag deactivates if a child is in the front seat?

 

There is a sensor to detect if there is weight on the passenger seat, as Bob's post shows. It doesn't directly go to the SRS ECU at all.
The seat position sensor was for the driver side airbag.
The system does detect if the buckles are being used, but I don't find any information on how that information is used.
Only the driver side buckle and seat position sensors go directly to the SRS ECU. I would imagine the passenger seat information comes from SIL through the body ECU, if it gets to SRS at all.

So, at best passenger airbag is disabled if no weight is in the seat, otherwise it is on. I am suspecting however that the airbag deploys whether seat occupancy is detected or not. The occupancy detector may simply be for the passenger buckle warning lamp.

 

This thread is an important issue for me. I pick up my Prius next Wednesda y (August 3). My wife is a slight woman, around 100lbs. She is worried that she would be killed by the bag if her air bag deployed. She's read about children in the front seat being killed (neck broken) and she doesn't want that to happen to her. She says she's about the same weight as some children around 12 years old, and she's read about 12-year-olds being badly injured by the air bag.

I don't suppose there is a disabling switch for the front passenger seat, is there?

 

Leo,
I would not worry about it. The main thing is for her to wear her seat belt and position the seat well back. I think the people injured or killed by air bags were not wearing seat belts. Also, air bags are much better now than the earlier generations. 80% of the safety factor comes from wearing the seat belt.

 

Heres what the NHTSA says about children and air bags:

"Air bags pose special hazards for any children who ride unrestrained or incorrectly restrained in the front seat. Like all occupants, children should always be properly restrained in safety seats or safety belts. Unfortunately, surveys indicate that as many as 35 percent of young children ride unrestrained. Pre-crash braking may throw an unrestrained child against the dashboard at or near the passenger air bag location. When this happens, the inflating air bag and its plastic cover can violently impact the out-of-place child with such force that it can injure or even kill the child. The safest place for all children is correctly restrained in the back seat of the vehicle."

So, it sounds like the issue is whether or not the passenger is properly restrained, not the weight of the passenger.

 

Here's a web page that talks about air bags and also references "short statured adults" is several places.

http://www.ou.edu/oupd/kidseat.htm

(search for the word "short" on the page)

 

Well, at this web site http://www.nhtsa.gov/NCAP/Cars/2562.html it appears the 2003 Prius had an optional air bag on-off switch. And at this site http://www.nhtsa.dot.gov/cars/testing/ncap.../cars/1721.html it appears that the 2005 Prius does not have one.

 

I'm not sure where I read this, if it was in the manual, sales lit. or on a website. But if I recall the Prius has a weight sensor in the seat. If you are under a certain weight, the deployment force of the airbag is reduced.

Terry

 

The current (2004/2005) Prius are dual-stage airbags, and do not detect the weight of the occupant, for use in calculating deployment force.

However, a more advanced airbag system will be a feature in the 2006 Prius (though it's not confirmed.)

Initially, I thought this might be airbags whose force of deployment is based on the weight of the occupant. However, after reading the links below, it sounds as if that weight-based deployement isn't implemented yet.

However, deployment that takes into account whether your seat belts are on or not are being implemented in cars; and really, this is probably the most useful criteria an airbag has. As mentioned in the Car Talk article sited in the link below, by law, airbags are supposed to absorb impact for someone who is not belted in. That's way more force than is needed for someone who is belted in; and supposedly, that "extra force" is what has caused injuries in the past.

Frankly, airbags should be used as supplements to seat belts -- not as replacements!
[hr:34798b1a97]
Anyway, here are a bunch of links detailing how safe airbags are for smaller people and children, what dual airbags are, etc., take a look at this old article.

I had many of the same questions when I was first shopping for a Prius; these articles provide good summary information on the topic.

 

Good article, thanks!