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Why Did It Take GM a Decade to Identify Ignition Switch Problems?

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William K.
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Re: Why are Air bags requiring the key switch on any way?
William K.   3/26/2014 3:31:10 PM
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Bob, the prolem that I see is that it should have been done that way from the very first airbag installation way back in history. The situations needing to fire the airbag with th engine switched off existed way back then, as well. I have had a stuck-wide-open throttle happen to me several times in cars of the sixties and seventies era, and that is a situation where a vehicle wouldn be going fast and have the engine switched off. So really, it is a case of it never was done right, and it should have been that way from the beginning. T%hen there would be no need to make such a big change. 

I saw at Chrysler a package able to fire the airbags after the battery was destroyed in a front-end collision, so I know that the technology was available in 1974, at least. I don't know if it ever n

made it into those cars, but even back then some were at least thinking about it.

Bob985
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Gold
Re: Why are Air bags requiring the key switch on any way?
Bob985   3/26/2014 3:21:47 PM
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That would be a good change, but changing a complex system such as that and testing it thoroughly enough that the confidence in correct operation is high enough to release the changes to production is very expensive. It also entails thinking about the system in a new way, and when you have as much history in the process of producing something like an automobile, there is a lot of inertia, and rightly so because _any_ kind of change introduces a risk of its own. So, while it is easy for us to say "this is how it should be done", in an industry with the gigantic economies of scale that automotive manufacturing has, even small changes cary enormous risk and cost - which may be why changes such as you have proposed, good changes, have not been and probably won't be introduced until the cost of not making them is high enough to drive the changes through the inertia.

William K.
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Platinum
Re: Why are Air bags requiring the key switch on any way?
William K.   3/26/2014 3:01:48 PM
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985, in a standard setup things would indeed all switch off when the switch was turned to the off position, which is why my comment was suggestijng a change in the system. While the system is on, it knows what the car speed is, and because of that it would be quite simple tp realize that the vehicle will keep on moving even if the system is switched off. So adding a bit of timing to keep the crucial systems powered for a few seconds if the key switch was switched off while the car was rolling would not only be fairly simple, but it would make a lot of sense.BUT, OF COURSE, it would require a departure from the way things had always been done, and so it would indeed be fought by the ones who never see any reason to change things.  And consider that if the speed sensing system were to stay energized, then it could continue to monitor the speed and allow the safety systems to remain powered until the vehicle stopped. The other situation where it would be valuable to keep the safety systems active with the ignition switched off would be the instance of a stuck throttle linkage, which would produce unwanted acceleration, which would prompt any clear-thinking individual to switch off the engine. 

SO, just because the car controller doesn't work that way now does not mean that it would not be a life-saving idea to make it work that way. 

Bob985
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Gold
Re: Why are Air bags requiring the key switch on any way?
Bob985   3/26/2014 9:43:35 AM
With the ignition off, I can't imagine that the circuitry that measured the speed would still be powered to provide a speed input to the airbag controller, and the airbag controller probably wouldn't be powered either. Virtually all the electronics is probably shut down when the ignition is turned off to avoid discharging the battery.

Charles Murray
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Blogger
Re: Why are Air bags requiring the key switch on any way?
Charles Murray   3/18/2014 6:31:59 PM
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I agree with you, backwater. I can't imagine any engineer foreseeing this problem. That said, they learned of the problem in 2004, and failed to identify it correctly or remedy it after they had a better understanding of it.

Backwater
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Iron
Re: Why are Air bags requiring the key switch on any way?
Backwater   3/17/2014 9:10:07 AM
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Finally, an honest answer of how the engineering managment works!  After they fire all the persons connected to problem, no one will be left to solve problem.  I have been a design engineer for 45 years and have only had two customers say "well it did not work, just like you said it would not, but you designed exactly what I asked for, not your fault".

Lets have a show of hands, how many designers out there could have foreseen the heavy key torque turning off the ignition and even better yet, how would you test for it.

etmax
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Gold
Re: suppliers
etmax   3/16/2014 9:14:04 PM
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I worked for delco electronics in the early to mid nineties as they were trying to spin off part suppliers they owned which looking at the state of a lot of them now was about as short sighted as of-shoring. Anyhow it was normal with Delco to retain part No.s if form fit and function didn't change. changing the torgue performance a switch in my mind is function and should have seen a P/N change.

William K.
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Platinum
Re: Why are Air bags requiring the key switch on any way?
William K.   3/14/2014 9:44:24 PM
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The whole problem with the airbags failing to deploy could have been solved if the algorithm had used vehicle speed to decide if the system should be disabled. Wires do break and switches may accidentally get switched off, but if the system knew that the car was still rolling at 45MPH it could keep the protection on. So that failure is pure code-specification error.

The mechanical flaw was the slot in the top of the key, allowing the heavy keychain to create torque to turn the key.

And the part number problem is undoubtedly that nobody wanted the top bosses to know that there had been a problem, because being responsible for a problem can end any hope of advancement in one's career at an auto company. Been there, done that, and I carry the scars to prove it. And all I did was report a problem on a part that our purchasing people selected. And that was for the EFM program, which was cancelled for other reasons. The guilty know who they are.

bobjengr
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Platinum
IGNITION SWITCH PROBLEMS
bobjengr   3/9/2014 7:36:36 AM
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It's no real consolation, but the appliance industry has the very same problems relative to solving nagging issues.  There are several problems discovered by home owners and users that remain on the "top ten" list year after year. Always, always number one (1) is electrical and electronics.  Now, for the most part, these issues are not nearly as critical as the one mentioned in you post.  Thirteen (13) deaths are certainly tragic.  GE had such as issue with an electronic  re-ignition system applied to  gas burners.  The system would fire, even when the gas valve was not energized.  We had complaint after complaint that sparking would occur at 2:00, 3:00, 4:00 A.M., etc.  in the morning.  Our sales teams would say "why can't you geniuses fix this problem".  Finally we did--we took it off the market.

  I never will forget, Ross Periot told GM, "Let's make one item-one component that is world class and not tied to cost".  He chose a cigarette lighter. They thought he was nuts and finally kicked him off the board of directors. (Maybe he left voluntarily but he was gone after just a few years.) I agree with one of the comments in that Federal oversight is really lax on this one as well as GM management.  Great post Charles.

Charles Murray
User Rank
Blogger
Re: Switchs
Charles Murray   3/7/2014 4:52:47 PM
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Thanks for the heads-up, Backwater. We were not aware of any Fox News references.

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