GM Chief Executive Mary Barra said Monday she still does not know why its took years for the automaker to recall cars with dangerously faulty ignitions, but pledged to find out. In testimony prepared for a Congressional hearing Tuesday into the ignition problem, tied to 13 deaths, Barra promised to be "fully transparent" over what kept General Motors from addressing the problem for 10 years. She said management would take responsibility for the issue, and that GM "will do the right thing." "More than a decade ago, GM embarked on a small car program. Sitting here today, I cannot tell you why it took years for a safety defect to be announced in that program," Barra said in remarks prepared for the hearing Tuesday of the investigations subcommittee of the House Energy and Commerce Committee. "When we have answers, we will be fully transparent with you, with our regulators, and with our customers." GM is facing probes by at least two Congressional committees as well as the US Justice Department after documents which showed it had received hundreds of complaints of the faulty ignitions since 2004. The company has since recalled 2.4 million cars covering the model years 2005 to 2010 over the ignitions, which can abruptly switch into "accessory" or "off" position while driving, especially when the car is jolted. That can turn off the car's electrical systems, including its safety airbags. GM says it has evidence of more than 30 accidents in which the airbags did not inflate, with the ignition apparently the problem, and 13 deaths as a consequence. The independent Center for Auto Safety says it has tracked 303 accidents in which the airbags did not inflate. Barra said the company was moving aggressively to address any outstanding safety problems with any of its vehicles, announcing multiple recalls over the past two weeks. She said an independent investigator was recruited to conduct a "thorough and unimpeded" probe into what happened in the ignitions case. Once his report is in, she said, "my management team and I will use his findings to help assure this does not happen again. We will hold ourselves fully accountable." Barra did not say how the company would address the claims and lawsuits against GM by people injured, or the families of those killed, in accidents allegedly involving the faulty ignitions. In principle, the government's rescue of the company and taking it through bankruptcy reorganization in 2008-2009 may have indemnified it against claims dating to before the bankruptcy.