But Barra, who took the helm of GM (GM) in January, will tell legislators in a congressional committee scheduled today that the company is investigating why it happened and has accelerated efforts to fix faulty ignition switches, according to her prepared testimony released Monday.

Barra has asked former U.S. Attorney Anton Valukas to investigate the actions of GM. Valukas has been give “free rein” regardless of the outcome, according to Barra.

MORE: GM recall: A civil case or criminal prosecution?

“I want to stress that I’m not waiting for his results to make changes,” Barra said in her prepared testimony.

As evidence of her proactive approach, Barra pointed to the naming of a new vice president for global vehicle safety and the commissioning of two additional production lines to make new replacement parts for vehicles that are no longer in production.

The House Subcommittee on Oversight and Investigations hearing scheduled for 2 p.m. ET will review the GM ignition switch recall, and legislators are expected to  focus on how the automaker and the National Highway Traffic Safety Administration responded to complaints from customers.

The hearing comes just one day after GM announced a separate recall of 1.3 million vehicles in the U.S. over concerns they may experience a sudden loss of electric power steering.  On Friday, GM extended its ignition switch recall by another 824,000 vehicles to cover all model years of the Chevrolet Cobalt and HHR, Pontiac G5 and Solstice, and the Saturn Ion and Sky in the U.S. because faulty switches may have been used. In all, the ignition switch recall affects 2.19 million vehicles in the United States.

The company also announced Monday that it has more than doubled its first-quarter charge to $750 million to cover the cost of recall-related repairs. This amount includes a previously disclosed $300 million charge for three safety actions announced March 17 and the ignition switch recall announced Feb. 25.

MORE: GM’s recall scandal: A scorecard on Mary Barra

GM’s total number of recalled vehicles in the U.S., including the power steering issue, ignition switch, and three other safety issues, has now surpassed 5 million.

In February, GM informed the NHTSA about a defect in the 2005-2007 model year Chevrolet Cobalt and the 2007 Pontiac G5 vehicles. Under certain conditions, the ignition switch can move out of the “run” position, causing a partial loss of electrical power and the engine turning off, according to GM. The risk increases if a driver’s key ring is carrying added weight or if the vehicle experiences rough road conditions. When the ignition switch is not in the run position, the air bags may not deploy if the vehicle is involved in a crash.

Problems with the ignition switch were identified as early as 2001 in a pre-production report for the model year 2003 Saturn Ion, according to documents provided by the House subcommittee. The report said a design change resolved the problem.

However, issues persisted, and in 2004 GM opened an engineering inquiry to look into a complaint that a 2005 Chevrolet Cobalt vehicle could be “keyed off” while driving. Ultimately, no action was taken. A year later, the driver of a 2005 Chevrolet Cobalt was killed in a crash. A NHTSA investigation determined the frontal airbag system didn’t deploy and that the vehicle power mode status was in “accessory,” not “run.”

NHTSA’s acting administrator David Friedman will tell legislators today that the agency did examine issues with the non-deployment of airbags in the recalled GM vehicles, but at the time did not find “sufficient evidence of a possible safety defect or defect trend that would warrant opening a formal investigation.”

In his prepared testimony, Friedman deflects the blame, noting that “GM had critical information that would have helped identify this defect.”