General Motors Co. Chief Executive Mary Barra is set to tell a congressional subcommittee this week that she would confront the auto maker's internal problems and make the tough changes needed to improve its record on safety, reported The Wall Street Journal.

"I know some of you are wondering about my commitment to solve the deep underlying cultural problems" detailed last week by an outside investigation of a troubled recall of a defective ignition switch, Ms. Barra will tell members of the House Energy and Commerce committee, according to written testimony released Tuesday ahead of her appearance on Wednesday.

"The answer is I will not rest until these problems are resolved," Ms. Barra says in her written remarks, adding "I am not afraid of the truth."

The defective ignition switch has been linked to at least 13 deaths and was known as faulty to GM engineers even before it first started appearing in the company's small cars in 2002. But the company failed to understand its seriousness and didn't begin to correct it until earlier this year.

Failures and missteps in the matter by the nation's largest auto maker were laid out last week in a 315-page report on an investigation led by Anton Valukas, a former U.S. attorney who is now chairman of Jenner & Block LLP, a Chicago law firm.

"There was a lack of accountability, a lack of urgency, and a failure of company personnel charged with ensuring the safety of the company's vehicles to understand how GM's own cars were designed," Mr. Valukas says in his own written testimony to be presented Wednesday to the House committee.

"We found failures throughout the company including individual errors, poor management, Byzantine committee structures, lack of training, and inadequate policies," Mr. Valukas says.

The appearance of Ms. Barra and Mr. Valukas comes as GM is recalling an additional 3.37 million cars in North America to replace potentially faulty ignition keys. Since the beginning of the year, GM has recalled more than 20 million cars in North America.

GM will rework or replace the ignition keys on 2000 to 2014 model-year cars in the U.S. because the ignition switch may inadvertently move out of the "run" position if the key is carrying extra weight and experiences some jarring event.

The auto maker said it would take a $700 million charge in the second quarter, ended June 30, to cover the costs of several recalls this quarter. The expense is in addition to the $1.3 billion the company spent in the first quarter.

Ms. Barra first appeared before the Energy and Commerce panel's subcommittee on oversight and investigations on April 1, and came under heavy criticism from lawmakers. Since then, Mr. Valukas led an investigation that included interviews with more than 230 people and reviewed more than 41 million emails and other documents.

The ignition switch was used in compact cars such as the Chevrolet Cobalt, Pontiac G5 and Saturn Ion, and was liable to slip to the off position if jarred or bumped. That cut power to the air bags and prevented them from deploying in a series of frontal crashes.

Mr. Valukas's findings, presented last week, highlighted the actions of one GM engineer who approved the ignition switch even though it failed to meet GM's standards, and later modified it but concealed the change, which prolonged the search for the cause.

But he also found many others at GM were at fault. "As fatalities and injuries mounted in cases in which air bags did not deploy in Cobalts, GM personnel displayed no sense of urgency in determining the cause," he says in the written testimony he'll provide on Wednesday.

Ms. Barra will tell the House committee that GM is already taking action in response to the Valukas report. Fifteen individuals who are named in the Valukas report are no longer working at GM, and the company is working on devising a method of paying compensation to the families of people who died in crashes in which the ignition switch prevented air bags from deploying.