The U.S. National Highway Traffic Safety Administration said on Friday it was opening a preliminary probe into 877,710 vehicles manufactured by General Motors , after receiving reports alleging engine failure.

Sean Duffy, President-elect Donald Trump’s nominee to lead USDOT, promised to not interfere with ongoing NHTSA investigations into Tesla if confirmed as secretary.

Sean Duffy, Donald Trump’s pick to lead the Department of Transportation, said he would allow safety investigations into Tesla’s advanced driving technology to proceed, possibly setting himself up for a clash with a top supporter of the president-elect.

Sean Duffy promised to not interfere in ongoing agency investigations into Elon Musk’s electric car company if confirmed to head the department.