General Motors CEO Mary Barra on Thursday will provide an update on the automaker’s ignition-switch safety recall, a briefing to employees, journalists and Wall Street analysts likely to include findings from an internal investigation into why cars with the deadly defect were not called back for repair earlier.

Barra will speak to GM employees from the automaker’s Warren, MI, technical center via a global broadcast tomorrow at 9 a.m. (EST) before meeting briefly with the media. She will host a conference call with the financial community later in the afternoon.

GM will not comment on content of the event, beyond calling it an update on the recall.

The automaker earlier this year launched a global recall campaign bringing back 2.6 million Chevrolet, Pontiac and Saturn small cars built between the ’03 and ’10 model years with defective ignition switches linked to 13 deaths and 47 crashes. The recall affects upwards of 2.2 million vehicles in the U.S.

GM documents reveal the automaker had knowledge of the defect early in the production of the vehicles, but it is unclear when a connection was drawn between the problem, in which the ignition key can slip out of the “run” position and into “accessory” or “off” and shut down safety equipment, and the deaths and crashes that would occur later.

A redesign of the part in 2008 did not include a standard engineering change to the part number, and experts suspect the oversight led to complication tracking the defect down.

It also has been unclear how far knowledge of the problem traveled up the GM chain of command, although Barra and her predecessor Dan Akerson have said they knew nothing of the issue.

The circumstances led GM to launch in March an internal investigation into why the extent of the defect took so long to uncover. Former U.S. Attorney Anthony Valukas has led the inquiry and his findings are expected to have a long-term effect, not only on GM safety reporting going forward but also on its corporate structure and perhaps its future leadership.

The automaker since February has suspended two engineering executives on the small-car program with the defect and restructured its global engineering group putting a greater focus on safety, as well as appointing a safety chief with direct access to Barra.

NHTSA last month fined GM $35 million, the maximum penalty available, for not reporting the defect earlier and the withholding of information.

“We have learned a great deal from this recall. We will now focus on the goal of becoming an industry leader in safety,” Barra says in a statement after the NHTSA fine. “We will emerge from this situation a stronger company.”

The automaker also faces civil litigation, a potential investigation by the U.S. Department of Justice and will learn within weeks the findings of another internal study focused on potentially compensating victims and their families.

Financial damage to the automaker has reached $1.7 billlion, although sales in the three months since the recall launched have not deteriorated.

jamend@wardsauto.com