WASHINGTON -- Despite concerns that airbags failed to deploy in some General Motors Co. cars, federal regulators twice declined to open formal investigations to determine the cause, according to a congressional investigation into delays in recalling the vehicles.
In addition, the automaker approved the part that caused the problem, an ignition switch, although officials from the supplier said that testing indicated it did not meet GM's original specifications, a House Energy and Commerce committee said Sunday in a memo summarizing its probe.
GM Chief Executive Mary Barra and the head of the National Highway Traffic Safety Administration, David Friedman, are scheduled to testify Tuesday at a hearing by the Oversight and Investigations subcommittee into the reason for delays in recalling vehicles with the faulty ignition switch.
The part has been linked to a series of crashes and at least 12 deaths in six GM models and the recall of more than 2.4 million vehicles.
NHTSA and the Justice Department have opened investigations into why it took so long for GM to recall the vehicles. Documents indicate the company knew about the problem as early as 2001.
The committee has reviewed more than 235,000 pages of documents from GM and NHTSA as part of the investigation, and "they paint an unsettling picture," said Rep. Tim Murphy (R-Pa.)
The committee's 16-page memo provides a detailed timeline of the ignition switch issue based on its investigation.
After some crashes involving GM vehicles in which airbags did not deploy, the chief of NHTSA's Defects Assessment Division emailed other agency officials in September 2007 proposing an investigation into problems in 2003-06 Chevrolet Cobalts and Saturn Ions.
The email said there was "a pattern of reported non-deployments" of airbags in complaints from vehicle owners that first was observed in early 2005.
At the time, GM indicated "they see no specific problem pattern."
A PowerPoint presentation prepared by the Defects Assessment Division, dated Nov. 17, 2007, said its review of the problem was prompted by 29 complaints and four fatal crashes.
But NHTSA's Office of Defects Investigation declined to investigate further.
Officials from that office told House committee staff that "the panel did not identify any discernible trend and decided not to pursue a more formal investigation," the memo said.
In 2010, after another accident in which the airbags in a Cobalt failed to deploy, NHTSA's Office of Defects Investigation again considered whether there was a problem "but determined the data did not show a trend," the memo said.
GM did not begin recalls until February of this year. It had recalled about 1.6 million vehicles, including 2003-07 Saturn Ions, 2006-07 Chevrolet HHRs, 2006-07 Pontiac Solstices, 2006-07 Saturn Sky models, and 2005-07 Chevrolet Cobalt and Pontiac G5 models.
On Friday, GM added 824,000 vehicles to the recall, including Chevrolet Cobalts, Pontiac G5s and Solstices, Saturn Ions and Skys from the 2008-11 model years and Chevrolet HHRs from the 2008-11 model years.
In February 2002, Delphi, which supplied the ignition switch for the recalled vehicles, submitted a part approval document to GM for the switch. Delphi officials told House committee investigators that GM approved the part "even though sample testing of the ignition switch torque was below the original specifications set by GM," the memo said.
GM opened its own engineering inquiry in November 2004 into a complaint that a 2005 Cobalt could be "keyed off with knee while driving," the House memo said.
Three months later, GM engineers met to consider whether there were problems with the ignition switch that made it easy to accidentally turn off the engine, which also would prevent the airbags from deploying.
The engineers considered changing the torque needed to turn off the ignition switch "but were advised by the ignition switch engineer that it is 'close to impossible to modify the present ignition switch' as the switch is 'very fragile and doing any further changes will lead to mechanical and/or electrical problems," the memo said.
The engineering manager for the Cobalt project decided to close the review with no action. The main reasons cited for the decision were that changes would take too long, the costs were too high and that none of the proposed fixes seemed to fully solve the problem, the memo said.
A review "concluded that 'none of the solutions represents an acceptable business case,'" the memo said.
The committee said the documents it had reviewed "do not explain the criteria for an "acceptable business case" and how the decision was made in this case."