General Motors CEO Mary Barra testifies before Congress for a second day, taking heat from U.S. senators for not telling owners of cars with potentially defective ignition switches to stop driving them, as well as declining vocal support for new legislation designed to strengthen the defect-reporting process and failing to inject the automaker with a “fresh” dose of leadership.

One day after testifying before a panel in the House of Representatives, Barra opens her testimony before a Senate subcommittee on consumer-product safety with another apology to the victims of crashes involving vehicles with the badly designed switch, pledges the automaker will not shirk its responsibilities as the manufacturer of those small cars, and reiterates GM’s redoubled commitment to selling safe automobiles.

But lawmakers spare no bullets. They pepper Barra with questions about why the automaker has not fired the engineering manager who signed off on a redesign of the switch in 2006 without assigning it a new part number, an oversight many see as a cover-up of what at that time was already a mounting crisis for GM.

“For the life of me, I can’t understand why he still has a job,” says Sen. Claire McCaskill (D-MO).

Sen. Barbara Boxer (D-CA) goes a step further, accusing Barra, who for a second day often qualified her responses by saying an internal investigation by GM will yield answers to why the recall took a decade to occur and who was responsible, of failing to take the restructured GM in a new direction.

“I hate to say this, but if this is the new GM leadership it is pretty lacking,” she says, accusing Barra of being aloof. “You don’t know anything about anything.”

Barra says GM plans to make employees accountable for decisions surrounding the defective switch and the lack of immediacy to recall cars with the part, but warns it will be 45-60 days before the internal investigation completes.

GM has hired former federal proscutor Anton Valukas, now chairman of the law firm Jenner & Block, to investigate what went wrong.

“If there were decisions made by individuals that were inappropriate and some of the things I’ve seen I’m very troubled by,” she says during testimony on the cable television network C-SPAN. “As Mr. Valukas completes his findings, my leadership team will take steps, and if that means there are disciplinary actions, up to and including termination, we’ll do that.”

Barra points to multiple firings last year at the executive level in GM’s powertrain group, including the global leader of the unit, after uncovering deceptive methods of emissions-regulations testing in India.

Sen. Edward Markey (D-MA) takes Barra to task for not offering vocal support during her testimony for legislation he has authored designed to strengthen the defect-reporting process. The legislation would compel automakers to notify NHTSA of insurance claims against them, as well as lawsuits involving fatal crashes, and require OEMs to file safety research on cars involved in deadly crashes.

“I would like to look at the legislation in its entirety, look at what makes the most sense working with NHTSA to make sure the most valuable information is put forward,” says Barra, who later offered “conceptual” support to the legislation.

Markey replies, “I am very troubled that you are not willing to commit to ending this culture of secrecy at General Motors.”

Barra defends GM’s decision to recall every car produced with the questionable switch while advising owners to remove everything from the key ring except the ignition key, rather than tell them to stop driving the vehicles altogether. She says GM testing shows the cars are safe when operated that way.

Barra also notes GM has offered free loaner vehicles to owners of recalled cars if they are uncomfortable driving it, and that shipments of replacement parts to dealers begin next week.

Several of the senators tell Barra GM has not gone far enough.

“You all may want to revise that advice,” says Sen. Bill Nelson (D-FL).

NHTSA Acting Administrator David Friedman also testifies for a second day. Yesterday, Friedman told the House panel GM withheld critical information that could have led the safety organization to find a defect during early scrutiny of the airbag systems in the cars.

GM has determined the ignition switch unintentionally can bump out of the “run” position and into “off” or “accessory,” which will kill the engine and some electronics such as the airbags.

Joan Claybrook, head of NHTSA from 1977 to 1981 and current president emeritus of consumer watchdog Public Citizen, says NHTSA had enough information and failed consumers even more than GM did.

“It was a design defect,” she says of the faulty ignition switch during an appearance today in Detroit, “so it’s going to affect every vehicle that the part is in. They didn’t need all the other stuff the agency claims it needed. Just open the investigation.

“As far as I’m concerned, NHTSA gets an F-minus.”

But Claybrook holds GM’s feet to the fire, too.

“GM is primarily responsible here,” she says, adding later she believes the automaker is serious about changing the way it views safety.

“Barra has a great opportunity to change the company,” Claybrook says. “She has more power today than any GM exec has had. She says the customer’s safety is the most important thing (and) I want to see her make that structurally a part of GM.”

Following the hearing in Washington, GM issues a statement from Barra, saying issues raised in the hearing were “tough but fair.

“I appreciate the intense interest by the senators to fully understand what happened and why. I am going to accomplish exactly that, and we will keep Congress informed,” she says. “Meanwhile, we will continue doing all we can to repair our customers' vehicles and rebuild their trust in GM.”                                             

– with David E. Zoia in Detroit