Federal prosecutors are investigating General Motors' driverless car unit over its handling of an accident involving one of its driverless cars.
Cruise acknowledged the probe, as it released findings from its review of the October 2023 incident, in which one of its cars dragged a pedestrian who had been thrown into its path.
California revoked Cruise's permit.
Cruise, which also pulled its cars from the road elsewhere, said its actions in the aftermath fell "woefully short".
"We are profoundly remorseful both for the injuries to the pedestrian, as well as for breaching the trust of our regulators, the media, and the public," the company said.
The report commissioned by GM and conducted by an outside law firm found the firm did not provide a full picture to regulators in the immediate aftermath of the accident and did not update the press as it learned more.
It ascribed these lapses to "a failure of leadership within Cruise, inadequate and uncoordinated internal processes, mistakes in judgment, an "us versus them" mentality with government officials, and a fundamental misunderstanding of regulatory requirements and expectations".
The report said it had not found evidence to date that Cruise leadership or personnel intended to deceive or mislead when they briefed regulators on the accident on 3 October 2023.
It said technical issues had prevented a full viewing of its video of the accident, in which the car dragged the pedestrian for about 20 feet. But staff did not verbally provide an account to make up for that lapse, the report noted.
Staff also responded to press inquiries without being aware of the pull over manoeuvre and did not update their accounts.
Cruise, which is majority owned by General Motors, was one of the first companies to get a commercial robotaxi service going, winning approval for regulators to start charging for rides in San Francisco in August despite objections from activists, police and fire officials and others.
At the time, Cruise hailed it as an "historic milestone". It had predicted that the business could generate $1bn in annual revenue by next year.
In the weeks after the accident, a slew of leaders at Cruise, including its chief executive, left the company.
It announced plans to cut about 24% of its staff - or roughly 900 jobs - in December.
Cruise said on Thursday that it was cooperating with authorities, including the Department of Justice and the Securities and Exchange Commission.
Safety authorities were already known to be investigating.
"We believe that, over time, autonomous vehicles can significantly reduce the number and severity of car collisions which result in more than 40,000 deaths on U.S. roads each year. This is what motivates our work," the company said.
"We know our license to operate must be earned and is ultimately granted by regulators and the communities we serve. We are focused on advancing our technology and earning back public trust."