UPDATE | More on GM's ignition switch problem

GM knew that the ignition switch did not meet torque specifications, Barra said.

“As we know now, it’s not acceptable,” she said.

There were two proposed fixes, but they were nixed on the basis of cost, according to the subcommittee investigation.

Barra said the company has moved from a cost culture to a trust culture, since its restructuring in 2007.

When pressed for answers to some specifics about when GM knew about problems associated with the part, Barra often deferred, saying the information would be part of the ongoing investigation she recently opened.

She said she was getting updates on the investigation as it proceeds.

GM will begin shipping new ignition switches this week, which use the old design but meet GM specifications and standards.