A Fiat Chrysler executive said Thursday said the automaker plans its own investigation into the role of a Jeep Grand Cherokee in the death of Star Trek actor Anton Yelchin.

Yelchin died instantly on Sunday after his 2015 Grand Cherokee rolled backwards and pinned him against a concrete mail box outside his Los Angeles home, according to police. 

Fiat Chrysler had announced a recall of the car and others in April after the US auto safety regulator said 117 crashes and 28 injuries had been linked to the vehicles rolling off freely when drivers thought they had locked them in "park".

Mike Manley, president and chief executive of the Jeep brand at FCA US, the US arm of Fiat Chrysler, said the automaker has not yet been able to examine the vehicle and the circumstances around Yelchin's death.

"We're waiting to be able to start our own investigation," Manley told reporters. "Obviously, we would like our own people to go over the vehicle."

Last year, the US National Highway Traffic Safety Administration investigated hundreds of reports that 2015 Jeep Grand Cherokees like Yelchin's would move freely even after drivers thought they were in "park" gear, which should immobilize them.

The NHTSA said the fault was related to the design of the cars' automatic transmission gear shifts.

FCA's April recall covers one million vehicles, including 2014-2015 Jeep Grand Cherokees.

On Monday, FCA said it was "premature to speculate on the cause of this tragedy." 

But late last week, the company told dealers it was addressing the problem with a software update that would effectively immobilize the cars if there is no driver in place. 

"It will be ready by the end of the month," Manley said of the fix.

He declined to answer questions about the potential impact of the accident on the company.

"I think FCA has taken the safety of its vehicles very, very seriously. That's an absolute statement of fact," Manley said.

Yelchin's death occurred just as FCA was about to launch a joint marketing effort for the Jeep Grand Cherokee with the new blockbuster film "Independence Day: Resurgence".