CEO Mary Barra will lead an employee meeting to discuss the report and hold a news conference afterward.
Read MoreGM expects recall probe won't blame CEO
GM has hired former U.S. Attorney Anton Valukas to investigate why it took the company more than 10 years to recall about 2.6 million small cars with faulty ignition switches. The company says the problem has caused at least 13 deaths, but trial lawyers suing GM say the toll is at least 60.
Documents show engineers in the company knew about the problem as early as 2001.