DETROIT -- Stung by rising warranty costs, General Motors decided in the mid-1990s to pull design work for ignition and turn-signal switches from suppliers and put its own employees in charge. One of the first projects for the in-house team was the ignition switch for the Saturn Ion and Chevrolet Cobalt.
"We wanted to have control over the design," Ray DeGiorgio, the lead design engineer for the Ion and Cobalt ignition switch, said in an April 2013 deposition obtained by Automotive News. "So we brought them in-house."
That part has now been linked to at least 34 crashes and 12 deaths over the past decade. It's also at the center of a deepening mystery in the wake of GM's recall of 1.6 million 2003-07 vehicles fitted with the defective ignition switch:
Why did GM authorize a redesign of the part in 2006, eight years before the recall? And why was the change made so discreetly -- without a new part number -- that employees investigating complaints of Ions and Cobalts stalling didn't know about it until late last year?
These questions, among many that will be posed by lawmakers and federal safety regulators looking into GM's handling of the recall, have confounded some former GM engineers, who say the company's reports to regulators describe a sequence of events that was fundamentally at odds with standard operating procedure.
Not assigning the new part number would have been highly unusual, according to three people who worked as high-level GM engineers at the time. None of the engineers was involved in the handling of the ignition switch; all asked that their names not be used because of the sensitivity of the matter.
"Changing the fit, form or function of a part without making a part number change is a cardinal sin," said one of the engineers. "It would have been an extraordinary violation of internal processes."