The investigation involves how the automaker handled reports of unintended acceleration in Toyota vehicles, and the deal to end the probe could cost Toyota around $1 billion, the Journal reported.
Toyota's legal difficulties over the issue would be far from over, but the deal would close the door on allegations the company withheld information from the public or issued false information about problems that led to a worldwide recall of 12.4 million vehicles, 10.2 million of them in the United States.
Nearly 400 individual lawsuits have been filed, some of them wrongful death suits.
Toyota has paid $66.2 million to the National Highway Traffic Safety Administration in four different fines levied from 2010 to 2013 for being slow to inform the public of a safety concern. It lost a wrongful death suit in October 2013, which helped push the company to become more aggressive setting individual lawsuits, the newspaper reported.
After losing the case, Toyota reached a financial settlement with the plaintiffs privately, keeping the size of the settlement away from public view.
Toyota agreed to pay $1.1 billion to vehicle owners in a class action suit filed to recoup losses owners would face when selling vehicles tainted with the possibility of unresolved unintended acceleration problems.
The NHTSA ruled in 2010 unintended acceleration contributed to the deaths of five people in two crashes.