The chief executive of General Motors and the former prosecutor hired by the company to investigate why it failed to recognize a fatal defect in Chevrolet Cobalts and other small cars will testify before a House subcommittee next Wednesday, reported The New York Times.

The House Energy and Commerce Committee’s subcommittee on oversight and investigations will call Mary T. Barra, the chief executive, and Anton R. Valukas, the former United States attorney whose report on June 5 was a scathing critique of management culture. The company dismissed 15 employees, including at last three senior corporate lawyers, and disciplined five in the wake of the report.

In April, Ms. Barra endured withering criticism from lawmakers when she testified before the same House panel, as well as a Senate subcommittee the following day. She deferred questions at least 54 times, saying she could not talk freely until the internal investigation was complete.

“Next week, we will have the chance to get those answers and compare the company’s findings with our own,” said Representative Fred Upton, a Michigan Republican and the chairman of the full committee, in a statement with Representative Tim Murphy, a Pennsylvania Republican who is chairman of the subcommittee.

The committee staff is poring over hundreds of thousands of pages of documents.

“Mr. Valukas’s exhaustive report revealed disturbing truths about G.M.’s systemic and cultural failures that allowed this problem to go undiagnosed for over a decade,” the two Republicans said, “but many questions remain unanswered about the recalls and resulting changes within the company.”

Representative Diana DeGette of Colorado, the ranking Democrat on the subcommittee, will ask about how G.M. is approaching the problem of its poor internal communications, with one group of engineers not knowing what another is doing, a problem Ms. Barra referred to as “silos.”

Ms. DeGette will also ask about compensation for crash victims, her staff said. But G.M. has delegated that issue to another outside expert, Kenneth Feinberg, a lawyer who specializes in allocating payments to victims in disasters. Mr. Feinberg has not yet given his recommendations on whom G.M. should pay, and how much, for the Cobalt crashes. His recommendations are expected this month.

Another question likely to surface is who was fired or disciplined, and who was not.

The Senate panel also plans a follow-up hearing, but not until summer.

In a statement, G.M. said Ms. Barra was looking forward to talking with lawmakers.

“Ms. Barra wants to return to Congress and update the House Energy and Commerce Committee members on the actions G.M. is taking in response to the ignition switch recall,” the company said in a statement. “As outlined by Ms. Barra last week, these efforts include fixing the failures identified in the Valukas report, building a culture centered on safety, quality and excellence, and doing what’s right for victims and their families.”