Although the results of the internal investigation will get plenty of attention, the changes GM puts in place following the probe will be of greater interest to Wall Street analysts and investors.
Barra already has made several moves to shore up the company's reputation when it comes to handling defects and recalls. Jeff Boyer was named vice president, global vehicle safety and, since taking over, he has overseen a review of complaints that has led to a wave of recalls. This year, GM has recalled more than 15 million vehicles worldwide.
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Within the last two weeks, General Motors raised the number of crashes linked to the faulty ignition switches to 47, from 31.
The company has also reported that there were 13 fatalities linked to accidents involving recalled vehicles where the airbag did not work because the ignition switch failed and cut power within the car. But lawyers for victims contend GM is underreporting the number of accidents and deaths linked to recalled vehicles.
In addition to releasing the report, GM is also expected to announce the structure of a compensation fund for victims of the ignition switch recall. That fund will be run by Ken Feinberg, who also oversaw victim compensation funds following the Sept. 11 terror attacks, the BP oil spill and the Boston Marathon bombings.
—By CNBC's Phil LeBeau
Questions? Comments? BehindTheWheel@cnbc.com.