Skip to comments.An Engineer’s Eureka Moment With a G.M. Flaw
Posted on 03/30/2014 1:19:58 PM PDT by jazusamo
DETROIT Somewhere inside the two-inch ignition switch from the 2005 Chevrolet Cobalt was the clue that Mark Hood was seeking.
Mr. Hood, an engineer in Florida, had photographed, X-rayed and disassembled the device in the fall of 2012, focusing on the tiny plastic and metal switch that controlled the ignition. But even after hours of testing, Mr. Hood was at a loss to explain why the engine in Brooke Meltons Cobalt had suddenly shut off, causing her fatal accident in 2010 in Georgia.
It was no small matter to her family, which had hired Mr. Hood for their lawsuit against General Motors.
Then he bought a replacement for $30 from a local G.M. dealership, and the mystery quickly unraveled. For the first time, someone outside G.M., even by the companys own account, had figured out a problem that it had known about for a decade, and is now linked to 13 deaths.
The discovery was at once subtle and significant: Even though the new switch had the same identification number 10392423 Mr. Hood found big differences. A tiny metal plunger in the switch was longer in the replacement part. And the switchs spring was more compressed. And most important, the force needed to turn the ignition on and off was greater.
There was a substantial increase in the torque of the switch, Mr. Hood said. We took measurements. And they were very different.
So began the discovery that would set in motion G.M.s worldwide recall of 2.6 million Cobalts and other cars, and one of the gravest safety crises in the companys history.
(Excerpt) Read more at nytimes.com ...
Functional specs on components manufactured in the millionz are really not that bad of an idea.
In fact most long lived corps. learn and remember as time progresses.
I don't know about you but I feel relieved. /s
I wonder if the fine will be as hefty as the one that DOJ just dealt Toyota?
GM. Still sweating the details.
Now, the details behind the change have become critical issues in determining whether the automaker intentionally concealed a safety defect.
Don't think I'd call failing to resist your customers motions with adequate force, a "safety defect". Don't whack the ignition while you're driving. D'oh!
I wonder if they’ll even be fined.
It’s weird they kept the part number the same, looks like deception to me but maybe not.
Wow. That's a huge indicator of sloppy manufacturing process. Where was QA? I thought we tried to learn from Toyota? Traceability from functional requirements through design and on to production is pretty important. Inability to uniquely identify your components breaks the entire chain.
Im no fan of Government Motors, but black boxes exist for lawsuits which in turn will help inflate the cost of cars beyond reach, just like general aviation.
About 10 or 15 years ago, I rented a number of Olds Aleros and as I recollect, there were several of them that had a very serious problem. As you were turning left and giving it gas, the engine would just conk right out. Now imagine a car bearing down on you from the other direction as you are madly trying to restart the engine right in the middle of the intersection. I never did hear what the problem was all about as I dont believe it was just isolated to the cars that I had rented.
Not necessarily. In automotive, it’s common to keep the same part number for newer revisions of parts where the newer revision is a drop-in replacement for the old.
There were other complaints back then that hitting a bump or pothole in the road shut it off.
That's what Deviations or Waivers are for. The configuration should be recorded down to it's Least Replaceable Unit.
Proper identification and baselining is essential.
They may not have known it was causing the ignition to shut off. It could have just been an improvement to a part, “kaizen”. Or maybe parts did not meet spec, in which case there is a QA problem. Or maybe the specs were revised due to continuous improvement process or discovery of shut-off problem. These things need to be determined.
Does GM have to design and build each and every one of it's parts to withstand a "bump".One wouldn't ordinarily anticipate an "out-of-the-way" item like an ignition switch to be bumped...particularly while the car's in motion.Imagine what commercial aviation would be like today if Boeing and Airbus had to design *all* of their parts to withstand an encounter with a flock of Canadian geese.
Somebody at Delphi knew about this safety problem, thus the change.
Nobody, repeat...NOBODY changes specs on a mass-produced component with unique engineering specifications for 3rd-party outsourcing without corresponding documentation, including version subsets.
That stated, draw your own conclusions on why GM/Delphi did.
Gee...I wonder if it was ‘2 rogue engineers in the Chicago engineering dept.’...
It’s my understanding they tried to kill this in the bankruptcy, but I’m too busy to follow with detail...
Government Motors. Obastard will just bail them aka the UAW out again.
You could not pay me enough to drive a Government Motors / UAW built death trap.
That’s my belief also.
All things being equal, I bet GM would be glad to be called embarrassingly sloppy -- but I suspect that wasn't the truth.
My understanding is the “new” GM was supposedly absolved from taking on the debts of the “old” GM.
However, any known flaws or defects were supposed to be declared to the bankruptcy court and supposedly this wasn’t.
Right you are. It is termed “running change”
Happens all the time with OEM of all kinds
With proper documentation, such as deviation or engineering change request, etc, however
Observing the obvious tragedy behind this (the deaths)...
...aside from that, the ‘old GM’ BS is what’s so laughably pathetic about all this.
Had GM just handled this on the up & up, it wouldn’t be ruled intentional (if it hasn’t already) and the problem might have cost them a lot less (plus fixed cars a lot faster and likely saved a few lives).
The sort of culture that’s responsible for this, top-down, doesn’t develop overnight and certainly doesn’t dissolve on the basis of a few personnel changes...
I don’t think it’s all as conspiratorial as the reporters wish to think. GM does, and has done, thousands of recalls over the years, and they’ve probably got a few dozen open recall projects going at any one time. It’s nothing new to them and they’ve done them for issues larger and smaller than this ignition switch. They have whole departments full of people that this is all they do. They do, also... make a huge priority out of getting well out in front of any recall that has even the tiniest safety implications.
Especially for recall issues as seemingly cheap and easy as a swapped out ignition switch. I don’t work for GM but I’ve been in those meetings with the people who make decisions like this— and everybody always has them bassackward. They really don’t care all that much how much a recall costs. What they care about is safety and the reputation of the company. A few million here and there doesn’t mean anything if the public starts to lose faith in GM as a safe brand. That really is how they think.
Keeping the part number is perfectly normal, so long as there is a REVISION change, and QA signed off on disposition of the earlier revision (use up existing, cease and scrap out, etc.).
Stating the part number is unchanged is uneducated journalist fear-mongering in its’ insinuation.
Not enough facts here.
(retired Military-Industrial Complex mechanical engineer)
............Not necessarily. In automotive, its common to keep the same part number for newer revisions of parts where the newer revision is a drop-in replacement for the old.................
I’m sure that is true, but then how is the parts department at your local chevy dealer know that he is dispensing the safety modified part????
Maybe a suffix, like 12345678A????
We now have the ability to feature a non-contact RFID type of run switch, including an old fashioned crank/start button.
GM part numbers never used to have a suffix. A whole new P/N was required for significantly functionally different parts.
I think you are wrong in this case. People died because the vehicles kept having unexpected shutoffs. The computers showed this. GM went out of its way to not acknowledge the cause, they had the part changed, and did not show on the replacement that it was different. They could have kept the exact number, changed the number, or added an “a” to show that it was different.
They were hiding it and you know it.
I am glad your life experience is different. I have worked for the government and major companies and my experience is that management cares not who dies especially if it impacts this years bonus.
sounds sloppy - rule i was used to over the years was “form, fit, or function”
(in this case it is a form change, a longer pin - either new p/n, or rev it)
discovery will focus on engineering documentation for sure.
I wouldn't assume, just because the switch has the same part number, that the evolutionary (internal to the switch) changes aren't traceable.
It;s a wonder nobody has sued for a car that can;t run out of gasoline. Same ultimate failure mode as far as vehicle control goes. Engine quits, Armstrong Steering becomes effective, etc. I can picture a designer's judgment that the unintended shutdown is a manageable event.
Nonsense. That’s the Hollywood “corporations are always evil” liberal party line.
People died... Well, sure. Upwards from 35,000 or 40,000 people die in cars every year. If six people die over five years in three different models of cars it doesn’t immediately follow that there is some obvious defect in a part that caused all of them. GM and Ford and everybody else has people data mining all those records constantly looking for commonalities that may point to a shared defect. It’s a lot harder to find them than it looks. There are thousands of common parts and there are thousands of unique parts. There are many times when it is only certain combinations of multiple parts that prove to be the problem.
Then they have to do vigorous testing to determine if the problem is in the design, the materials, the manufacture, or lately... Software. All of that takes more time. I’ve been in some of those meetings and I remember coming away, especially at first, being really impressed with how concerned they all were with getting it right and doing the right thing. They just aren’t the bad guys that liberal muckrakers make them out to be.
The detent inside the switch assembly isn’t a serviceable part.
I have a 1976 Chevy Dually 1 ton truck.
I bought it in April, 1986 with 100,000 miles on it. It now has 350,000 on it.
I have about 15 keys hanging on that key chain. NEVER had a single problem.
They are trying their best to remove weight from every new car in every possible place to get batter mileage.
Don’t want a plastic car myself.
... it is possible that he did not examine any GM documents related to the part. I do not think such docs would be proprietary. If the engineer were part of an ongoing lawsuit, then I think the discovery process might have made these documents readily accessible to him. Maybe (for one reason or another) he just didn't view the engineering drawings. But it sounds like he sure was scratching his head wondering, "What's going on??"
But if the engineering documents were properly maintained, they should have easily shown that revisions to low-level pieces of certain configuration items were made. It shouldn't have been hard to ask, "Why'd you change this part right here?"
It's an assumption on my part, but it seems reasonable that the change was made by GM and that the documents did not adequately reflect the change in form, fit or function. Either from sloppiness or malfeasance.
High-level identification (serial number, part number, what-have-you) may not tell the whole story, but the revision history should never be a secret or a mystery.
With all the stalk-mounted controls on the steering column, the ignition key isn't that out of the way. I don't know about this GM car, but in my toyota, when reaching for the cruise control with a gloved hand I can jangle the keys.
I'm sure all of us have a remote entry fob and at least one other key attached to our ignition keys. An old time Chevy dealer told me years ago not to load up my ignition key with lots of keys and other junk as it would cause premature ignition switch failure.
Well, it sure sounds conspiratorial to me, and I am an engineer from way back, where one of the major rules of the game was that different items had different part numbers, even if it was a drop-in replacement.
One of the things to note is that GM settled out of court in this particular case. This keeps other peopler from using the results of the engineer's work. There are many possible reasons for this, all involving economics, but I remember back when every time it looked like a trial was going to end up demonstrating legally that cigarettes really did cause cancer, the tobacco companies would quickly settle it, so that every new plaintiff had to go through that proof all over again starting a zero.
Your contention vs. mine would easily be resolved in discovery, when the plaintiffs would depose a GM engineer about these part numbers being the same, he would say it was common for drop-in replacements, and the the plaintiffs attorney would ask him for a list of all instances like this that he knew of. I believe that GM would never allow such a list to become public, because there would only be two possible outcomes: (1) it wasn't really very common,or (2) it happened all the time and the list would give other plaintiffs a great start on their defects.
A second reason to settle would be that if there are 13 deaths, how many other accidents have there been? Lots and lots of property damage, which insurance companies would love to take a crack at, and then hundreds of injuries, some permanent, some disabling, and some permanently disfiguring. The liability is enormous if the real truth comes out.
As far as the idea that being bumped wasn't an "expected" stress in the normal course of use, this is complete BS. A car is a confined space, with kids, pets, all sorts of stuff that can be foreseen happening in there. I have seen women with 20+ keys, 3 charm bracelets, 2 or 3 plastic key fobs and who-knows-what else hanging from their keys. Men do this less because it doesn't fit in a pants pocket. I have never seen any car company warn against excessive ballast on a key chain.
GM new this was going to happen.
Delphi told panel GM approved ignition switches below specifications
The ignition switch is separate from the “key lock cylinder”. The ignition switch is located on the steering column beneath the dashboard. I believe that jarring and/or wear can effect the internal contacts of the old style switch causing a break in continuity. This may or may not be associated with jarring of or dangling of weight on the “key lock cylinder”.
Thanks for linking, good catch and a most interesting article.
Yet more info that GM is hanging out there a mile. Tuesday and Wednesdays hearings with Mary Barra looks like they’ll be very interesting.
If the part is a safety replacement, then yes, it shouldn’t have the exact same number, for exactly the reason you mention. But it wasn’t clear to me from the article that that’s how this was viewed.
Back in 1979 or ‘80 I flew into Minneapolis and went to claim my reserved rental car at Avis. The gal said it was a blue Ford Granada in slot 14. When I got there, there was a blue Mercury Monarch in slot 14. After reporting this to the counter and being assured that it was the vehicle for me, and upon approaching it from the opposite side, I discovered that on the driver’s side it had the name plates, etc. of a Ford Granada, but on the passenger’s side, from which I originally approached it, it bore all the markings of a Mercury Monarch. Boo-boo on the assembly line.
I haven’t kept up with all the model names. GM actually named a car the Flaw?
Using the same part number for the redesigned switch with redesigned parts doesn't border on fraud. It is fraud!
Will Ray LaHood be advising Government Motors owners of affected cars to not drive their recalled cars??
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