This video by Machine Design magazine shows what is wrong.

The detent plunger was too short and it's spring too weak to firmly hold
the switch in the "run" position. So, extra weight on a keyring could
turn the ignition switch off. (By swinging I suppose.)

http://tinyurl.com/mdx67rn

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

On Sunday, May 18, 2014 12:59:00 PM UTC-4, wrote:
On Sun, 18 May 2014 12:49:11 -0400, Jeff Wisnia

wrote:





This video by Machine Design magazine shows what is wrong.



The detent plunger was too short and it's spring too weak to firmly hold

the switch in the "run" position. So, extra weight on a keyring could

turn the ignition switch off. (By swinging I suppose.)



http://tinyurl.com/mdx67rn



Jeff



The way I understand it your key chain would have to look like the

men's room key at a highway gas station.

It still takes a significant amount of weight to turn that key.



This is just typical of modern automotive engineering. They are not

looking at how big would be best, only how small they can get away

with.

That is true of just about everything in a car these days and explains

why a 6 MPH bump will do thousand of dollars worth of damage. They

only have to design for 5.

But in this case, I haven't seen any evidence that there
was any profit motive for the ignition switch plunger being
1/8" too short. An eighth of an inch additional length of a
tiny pin in a switch shouldn't make a difference in the cost
of the switch. Especially when you're GM and buying millions
of them.

Two other things about this. One is that there is a family
suing GM over this. I believe the parents were killed. They
were in the front seat, not wearing seat belts. Their infant
was in the back, not sure about in what. The child survived
and ia a paraplegic. Here's the interesting part. They
were driving along, apparently normally. A drunk driver
crossed the road, hit them head on. It was very major damage,
crumpled all the way to the fron seats. The airbags did not
go off and supposedly the key was found in the accessory
position. The only plausible scenario is that the force of
the collison caused the key to turn *before* the airbag
system could fire? I guess it's possible, maybe
because the airbag system needs enough force for it to go
off and by that time the decleration has caused the keychain
to move the key. So, it's a race between key turning and
bag firing....

The other crazy thing is GM had an instructional presentation
to it's employees on what they shouldn't say in memos discussing
engineering, safety issues, etc.

http://www.huffingtonpost.com/2014/0...n_5340385.html


When I first heard about this, I didn't think it was so bad,
as I can see a reason for not using some phrases that could look
bad in court someday. But if you look at that list, it's a joke.
Some of the forbidden words make some sense:

Hindenburgh
gruesome
you're toast
Titanic

Some I don't even understand:

Cobaine

Some I've never heard used in my life:

Kevorkianesque

And the worst part is that on that same list a

always
never
failed
safety
unstable


It looks like some nutty lawyers are running GM. I was thinking
of how difficult it would be to write a memo about something
without using those words. And those words were just examples.
When always and safety are on the list, IDK how you figure out
what should and shouldn't be on.

perhaps it would be safer if airbags always had power. since the worst that could occur and deploying some airbags in parked cars with no one inside

I have sat in cars waiting to meet someone with the ignition key off, or even removed.

ideally people should still be protected

On Sun, 18 May 2014 10:32:20 -0700 (PDT), trader_4
wrote:

On Sunday, May 18, 2014 12:59:00 PM UTC-4, wrote:
On Sun, 18 May 2014 12:49:11 -0400, Jeff Wisnia

wrote:





This video by Machine Design magazine shows what is wrong.



The detent plunger was too short and it's spring too weak to firmly hold

the switch in the "run" position. So, extra weight on a keyring could

turn the ignition switch off. (By swinging I suppose.)



http://tinyurl.com/mdx67rn



Jeff



The way I understand it your key chain would have to look like the

men's room key at a highway gas station.

It still takes a significant amount of weight to turn that key.



This is just typical of modern automotive engineering. They are not

looking at how big would be best, only how small they can get away

with.

That is true of just about everything in a car these days and explains

why a 6 MPH bump will do thousand of dollars worth of damage. They

only have to design for 5.

But in this case, I haven't seen any evidence that there
was any profit motive for the ignition switch plunger being
1/8" too short. An eighth of an inch additional length of a
tiny pin in a switch shouldn't make a difference in the cost
of the switch. Especially when you're GM and buying millions
of them.

Two other things about this. One is that there is a family
suing GM over this. I believe the parents were killed. They
were in the front seat, not wearing seat belts. Their infant
was in the back, not sure about in what. The child survived
and ia a paraplegic. Here's the interesting part. They
were driving along, apparently normally. A drunk driver
crossed the road, hit them head on. It was very major damage,
crumpled all the way to the fron seats. The airbags did not
go off and supposedly the key was found in the accessory
position. The only plausible scenario is that the force of
the collison caused the key to turn *before* the airbag
system could fire? I guess it's possible, maybe
because the airbag system needs enough force for it to go
off and by that time the decleration has caused the keychain
to move the key. So, it's a race between key turning and
bag firing....

The other crazy thing is GM had an instructional presentation
to it's employees on what they shouldn't say in memos discussing
engineering, safety issues, etc.

http://www.huffingtonpost.com/2014/0...n_5340385.html


When I first heard about this, I didn't think it was so bad,
as I can see a reason for not using some phrases that could look
bad in court someday. But if you look at that list, it's a joke.
Some of the forbidden words make some sense:

Hindenburgh
gruesome
you're toast
Titanic

Some I don't even understand:

Cobaine

Some I've never heard used in my life:

Kevorkianesque

And the worst part is that on that same list a

always
never
failed
safety
unstable


It looks like some nutty lawyers are running GM. I was thinking
of how difficult it would be to write a memo about something
without using those words. And those words were just examples.
When always and safety are on the list, IDK how you figure out
what should and shouldn't be on.

Nothing nutty about it, just good defense against emotionally worked
up juries who like to stick it to big corporations even when the
"victim" is at fault.

Does anyone know if that GM ignition switch recall extends to Canada or not and whether the Oldsmobile Alero is one of the models being recalled? My sister has an Oldsmobile Alero, but I don't know what model year it is.

excuse me my wife owned a cobalt, it had all sorts of lost power, engine quit, etc etc. then local dealer MUST of known the car had a design defect, it must of been to the dealer 15 times. my wife was very short and heavy and her key ring had everything but the kitchen sink on it..... power steering quit too.

she fit the profile for the problem exactly. we got divorced....

if you ask me GM should be required to pay every original owner who had complaints that fit the defect 5 grand each. so no manufacturer will ever cover up such a defect again!

On 5/18/2014 11:49 AM, Jeff Wisnia wrote:

This video by Machine Design magazine shows what is wrong.

The detent plunger was too short and it's spring too weak to firmly hold
the switch in the "run" position. So, extra weight on a keyring could
turn the ignition switch off. (By swinging I suppose.)

http://tinyurl.com/mdx67rn

Jeff


for want of a nail, a horse was lost ... it happens

"bob haller" wrote in message
news:4a5e3b3e-6b4a-4603-8537-

if you ask me GM should be required to pay every original owner who had
complaints that fit the defect 5 grand each. so no manufacturer will ever
cover up such a defect again!

It always makes me wonder when I hear about stuff like this: "What else are
they covering up?"

--
Bobby G.

On Sunday, May 18, 2014 1:32:20 PM UTC-4, trader_4 wrote:


Two other things about this. One is that there is a family

suing GM over this. I believe the parents were killed. They

were in the front seat, not wearing seat belts. Their infant

was in the back, not sure about in what. The child survived

and ia a paraplegic. Here's the interesting part. They

were driving along, apparently normally. A drunk driver

crossed the road, hit them head on. It was very major damage,

crumpled all the way to the fron seats. The airbags did not

go off and supposedly the key was found in the accessory

position. The only plausible scenario is that the force of

the collison caused the key to turn *before* the airbag

system could fire? I guess it's possible, maybe

because the airbag system needs enough force for it to go

off and by that time the decleration has caused the keychain

to move the key. So, it's a race between key turning and

bag firing....



I was talking to someone else about the above and they came up
with a scenario that may explain not only the above, but many of
the other crashes. IDK about you folks, but watching the media
reports they showed some of the crashed cars where people died,
and talked about the key moving, causing the power assist to the
steering and brakes to stop, and the airbags failing to deploy.
From that I assumed the scenario was that the key moved *first*
causing the loss of power steering and braking making the car more
difficult to control. The steering being more difficult, I get,
because that's going to happen instantly. The braking, given that
there is a vacuum reservoir, I would expect to be perfectly fine
for at least one full application of the brakes. If you pump, pump
a few times, then you'd use it up. So, I was wondering how the
key moving initiated the crash, since that is what the reporting
seemed to suggest.

But talking to a friend, he came up with a different scenario
that explains the specific odd crash I brought up in the case
above and could explain many of the other crashes too. In the case
above, the car was working fine, until a drunk driver came across
and hit them head on. What would a driver in the GM car likely do
at some point prior to impact in that case? Slam on the brakes.
And doing so, with a heavy keychain, the extreme deceleration
causes the key to move. That cuts off the airbags. So, a similar
thing could have happened in many of the other 13 deaths, ie
it wasn't the key moving that instigated the accident, through
the steering/braking being more difficult, but some other event.
The scenario being you're running off the road already headed to
a tree, whatever, you slam on the brakes, that moves the key, turning
off the airbags.

trader_4 wrote:

In the case above, the car was working fine, until a drunk driver
came across and hit them head on. What would a driver in the GM
car likely do at some point prior to impact in that case?

Slam on the brakes.
And doing so, with a heavy keychain, the extreme deceleration
causes the key to move. That cuts off the airbags. So, a similar
thing could have happened in many of the other 13 deaths, ie
it wasn't the key moving that instigated the accident, through
the steering/braking being more difficult, but some other event.
The scenario being you're running off the road already headed to
a tree, whatever, you slam on the brakes, that moves the key,
turning off the airbags.

Aren't cars made during the past 10 years (and moreso 5 years) supposed
to have sophisticated "black-box" data logging systems that record a lot
of what's going on with the car (steering wheel movements, braking,
speed, etc) compared to 10+ years ago?

So much more logging that it's become standard practice for cops to have
sophisticated data recovery tools sold to them by third-party equipment
makers with slick marketing that tells cops that there's valuable
evidence just waiting for them at crash scenes?

If so, then it should be a simple matter to know the state of the
ignition switch or airbags prior to, say, loss of main battery bus or
engine RPM offscale or zero (the loss of either one being the indicator
of impact damage in progress).

I never heard of that, but I haven't been looking to buy a new car. But, even if newer cars have such systems, that system might not monitor the car's key position because the system would presumably only work while the car is running, and in that case the key position is known without a black box to record it. It would only be a recorded parameter if the manufacturer expected the key position could change DURING a crash that they would bother to monitor it, but considering that turning the key off or to the accessory position could disable the air bags, that doesn't hold much water either because they should design the switch so that it doesn't turn no matter how violent the crash or no matter how much stuff is on the key chain.

The thing is that air bags are a life saving accessory. GM should have tested how the air bag deployment would be affected by people that have lots of stuff on their key chains. I know my father used to keep all kinds of stuff on his key chain, including a tiny flash light, a rabbit's foot and a small jack knife, and that's besides all the keys. I expect there are people with even more stuff than that.

On 5/18/2014 10:36 PM, bob haller wrote:
perhaps it would be safer if airbags always had power. since the worst that could occur and deploying some airbags in parked cars with no one inside

I have sat in cars waiting to meet someone with the ignition key off, or even removed.

ideally people should still be protected



If you are in a parking lot, the impact would not be hard enough to
trigger the airbags. If you got rear ended, the airbags would not deploy.

I'm not even sure if they would deploy in a front collision of a parked
car. I think rate of deceleration is a factor in the trigger. Standing
vehickles would not have deceleration, only impact.

I did a bit of reading on air bags tonight, and whether or not an airbag deploys, and which of the airbags deploy is not just a matter of how strong the impact is.

If the ignition is off, then there's no power to the vehicle's computer, and so no amount of impact will cause the airbags to deploy because the computer will not generate a signal to deploy the air bags.

In a collission, or if the vehicle's airbag sensors sense an impact, then within 15 to 20 milliseconds the vehicle's airbag computer decides whether or not to deploy an air bag and which air bag(s) to deploy. It takes into account the direction of the impact and the weight of the passengers in the seats. If the car gets hit from the back, then the passengers are pushed back in their seats, so deploying the front air bags won't help at. In that case, no matter how hard you're hit from the back, the front air bags will never deploy. If the car is moving slowly when the impact occurs, or the driver in the front seat is very small (like 70 pounds or less) then the front air bags may not deploy because the explosive deployment may cause more injury to the driver or passenger than the collission. In any collission or impact, the car's computer does a lot of calculations and within 15 to 20 milliseconds it decides whether or not to deploy air bags, and which air bags to deploy. Most of the time when airbags don't deploy it's not because the impact wasn't severe enough, it's because the car's computer decided not to deploy any air bags because the conditions didn't warrant it.

Air bags have an redundant deployment system. They require electrical power from the car's battery or alternator to deploy, but if electrical power to the airbags is interrupted as a result of the collision, air bags have a power capacitor that provides enough power to deploy the air bags for up to 90 seconds after the crash. So, if your car gets hit in the left front fender which causes the car's battery to go flying, the power stored in that capacitor still operates the car's computer and provides enough power to deploy the airbags in the car for up to 90 seconds. When you park your car, if it gets hit from the front by another car, the air bags can deploy for up to 90 seconds after you turn off the ignition. After that 90 second window passes, then there won't be sufficient power to run the car's computer or deploy the air bags, so no matter how hard you're hit after 90 seconds of turning off the ignition switch, the air bags won't deploy.

Or, at least, that's what I understand now.

On Monday, May 19, 2014 2:23:49 PM UTC-5, Ed Pawlowski wrote:


I'm not even sure if they would deploy in a front collision of a parked

car. I think rate of deceleration is a factor in the trigger. Standing

vehickles would not have deceleration, only impact.

Physics 101: Impact IS deceleration.

Acceleration/deceleration is a change in speed. You are going from zero to a negative forward speed if struck from the front while standing still. An accelerometer doesn't know the difference, unless it is somehow hooked up to the speedometer, and I don't think that's how airbags work.

I am sure it is not this simple in reality, but one would think that if front-ended while idling, the airbags SHOULD deploy.

If a car is stopped and the engine is shut down; that is another issue entirely, because you would have to determine whether the airbag system still has power while the engine is not running.

On Monday, May 19, 2014 6:10:46 PM UTC-4, nestork wrote:
I did a bit of reading on air bags tonight, and whether or not an airbag

deploys, and which of the airbags deploy is not just a matter of how

strong the impact is.



If the ignition is off, then there's no power to the vehicle's computer,

and so no amount of impact will cause the airbags to deploy because the

computer will not generate a signal to deploy the air bags.



I think here you mean that if the key has been off longer than the
stored energy period that you talk about below.



In a collission, or if the vehicle's airbag sensors sense an impact,

then within 15 to 20 milliseconds the vehicle's airbag computer decides

whether or not to deploy an air bag and which air bag(s) to deploy. It

takes into account the direction of the impact and the weight of the

passengers in the seats. If the car gets hit from the back, then the

passengers are pushed back in their seats, so deploying the front air

bags won't help at. In that case, no matter how hard you're hit from

the back, the front air bags will never deploy. If the car is moving

slowly when the impact occurs, or the driver in the front seat is very

small (like 70 pounds or less) then the front air bags may not deploy

because the explosive deployment may cause more injury to the driver or

passenger than the collission. In any collission or impact, the car's

computer does a lot of calculations and within 15 to 20 milliseconds it

decides whether or not to deploy air bags, and which air bags to deploy.

Most of the time when airbags don't deploy it's not because the impact

wasn't severe enough, it's because the car's computer decided not to

deploy any air bags because the conditions didn't warrant it.



Air bags have an redundant deployment system. They require electrical

power from the car's battery or alternator to deploy, but if electrical

power to the airbags is interrupted as a result of the collision, air

bags have a power capacitor that provides enough power to deploy the air

bags for up to 90 seconds after the crash. So, if your car gets hit in

the left front fender which causes the car's battery to go flying, the

power stored in that capacitor still operates the car's computer and

provides enough power to deploy the airbags in the car for up to 90

seconds. When you park your car, if it gets hit from the front by

another car, the air bags can deploy for up to 90 seconds after you turn

off the ignition. After that 90 second window passes, then there won't

be sufficient power to run the car's computer or deploy the air bags, so

no matter how hard you're hit after 90 seconds of turning off the

ignition switch, the air bags won't deploy.



Or, at least, that's what I understand now.


I saw on a car talk website where they said a similar thing,
ie that the bags have some reserve energy to deploy for some short
period eg couple mins, after the key is off. If that's true though,
then how do you explain the GM car crashes at issue, where the airbags
did not deploy? All the media reports I've seen say it's because the
key was not in the on position.

On Monday, May 19, 2014 7:05:04 PM UTC-4, Nicholas Kriho wrote:
On Monday, May 19, 2014 2:23:49 PM UTC-5, Ed Pawlowski wrote:





I'm not even sure if they would deploy in a front collision of a parked



car. I think rate of deceleration is a factor in the trigger. Standing



vehickles would not have deceleration, only impact.



Physics 101: Impact IS deceleration.



Wrong. Deceleration is a slowing down. In the example you're replying
to, a parked car being hit was cited. That is an *acceleration* of the
parked car. It doesn't matter from which direction it's hit. From
Newton, F = MA. Hitting the car applies a force and it accelerates.



Acceleration/deceleration is a change in speed. You are going from zero to a negative forward speed if struck from the front while standing still.

That may be true, but it's not deceleration. The parked car is accelerating.
It's going faster 100 ms after being hit than it was at 5ms.


An accelerometer doesn't know the difference, unless it is somehow hooked up to the speedometer, and I don't think that's how airbags work.



An accelerometer would record an acceleration, not a deceleration. The
parked car is speeding up, not slowing down. It's going faster 100 ms after being struck than it was 5ms after being struck.

And actually I'm pretty sure speed is also a component the computer looks
at.



I am sure it is not this simple in reality, but one would think that if front-ended while idling, the airbags SHOULD deploy.



Logically you would think so, but it depends on the exact criteria that the
airbag computer uses.



If a car is stopped and the engine is shut down; that is another issue entirely, because you would have to determine whether the airbag system still has power while the engine is not running.

Apparently from the media reports, the allegation, which I haven't seen
GM refute, is that the airbags did not deploy in these fatalities because
the ingnition key had moved from run to acc.

On Monday, May 19, 2014 9:00:44 PM UTC-4, wrote:
On Mon, 19 May 2014 16:39:57 -0700 (PDT), trader_4

wrote:



I saw on a car talk website where they said a similar thing,

ie that the bags have some reserve energy to deploy for some short

period eg couple mins, after the key is off. If that's true though,

then how do you explain the GM car crashes at issue, where the airbags

did not deploy? All the media reports I've seen say it's because the

key was not in the on position.



The air bags are fired electrically and I assume they are wired to the

ignition position not the accessory position.



That's what I thought too. But according to Nestor, he found where
there is an energy reserve of x minutes, for the airbags. I found a
similar discussion:

http://www.cartalk.com/content/will-...ing-not-moving


But I think the real answer is that it likely varies from manufacturer
to manufactuer and even NHTSA is confused. NHTSA testified to Congress
that they do have a reserve, like Nestor said, but GM says it's recall cars
airbags go inactive 150ms after the key moves from run.



http://www.autoblog.com/2014/05/16/n...-airbags-work/


"There might actually be a bit of a silver lining to General Motors' ignition switch recall of 2.6 million cars. In the end, it may mean safer vehicles on the road from every automaker. The debacle has shined a light on how little the National Highway Traffic Safety Administration actually understands about airbags and their deployment. The regulator is now working to change that, and it's investigating how to make the devices even safer.

In its Congressional testimony, NHTSA said that it believed the General Motors recalled vehicles had 60 seconds of power for the airbags after their ignition switches were turned off, according to The Detroit News. The automaker has denied this - its own research has found that the bags will only work for about 150 milliseconds after the ignition has been moved from the run position.

This discrepancy between GM and NHTSA investigations may lead to major improvements in how airbags work. The regulator has begun surveying automakers and airbag suppliers to learn more about how ignition position affects activation, according to the report.

At the moment, these airbag activation parameters remain unregulated. While the pyrotechnic devices legally have to be in cars, automakers tune their deployment differently, depending on their own internal standards. NHTSA's analysis could eventually lead to new regulations determining whether these safety devices should continue to work for a period of time after a vehicle is shut off. "

On Monday, May 19, 2014 9:56:19 PM UTC-4, wrote:
On Mon, 19 May 2014 18:18:46 -0700 (PDT), trader_4

wrote:



GM says it's recall cars

airbags go inactive 150ms after the key moves from run.



That is just a capacitor discharging. Not much of a reserve.

Yes, that's probably all it is in those GM cars. Given that NHTSA told
Congress that the airbags had a minute of reserve, as do some other
sources, it's not clear how other cars designs work. There is no
specific requirement, so who knows.