By David Shepardson

WASHINGTON (Reuters) -The National Highway Traffic Safety Administration said on Monday that General Motors' self-driving car unit Cruise will pay a $1.5 million fine after it failed to disclose details of a serious October 2023 crash involving a pedestrian.

Under the settlement, Cruise must submit to NHTSA a corrective action plan on how it will improve its compliance with reporting of serious incidents and face enhanced reporting requirements for at least two years.

Cruise also faces ongoing investigations by the Justice Department and the Securities and Exchange Commission following the accident in which one of its robotaxis in San Francisco struck a pedestrian after she was hit by another vehicle and dragged her 20 feet (6.1 meters).

In October 2023, Cruise employees tried to convince NHTSA not to open an investigation into the injury incident and submitted reports that failed to disclose the pedestrian had been dragged, a report commissioned by GM said.

Cruise Chief Safety Officer Steve Kenner said the agreement with the agency "is a step forward in a new chapter for Cruise, building on our progress under new leadership, improved processes and culture, and a firm commitment to greater transparency with our regulators."

NHTSA said Cruise submitted several incomplete reports for crashes involving automated driving systems including two tied to the October crash.

It discovered Cruise omitted details from the October 2023 crash reports after viewing video it requested from Cruise, which has also amended four other reports to provide additional detail on other crashes, the agency said.

NHTSA's investigation into whether Cruise is taking sufficient precautions with its autonomous robotaxis to safeguard pedestrians remains open.

In August, Cruise recalled 1,200 robotaxis over hard braking issues following a NHTSA probe into the safety of their autonomous driving systems.

GM said in July it would indefinitely suspend plans to use its self-driving Origin vehicle that does not have a steering wheel.

In response to the October accident and subsequent investigations, Cruise's CEO resigned last year and General Motors subsequently announced plans to scale back spending on the self-driving unit.

The California Public Utilities Commission imposed the maximum penalty of $112,500 on Cruise for its failure to promptly provide complete information to the commission about the crash.

(Reporting by David ShepardsonEditing by Bill Berkrot)