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.
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