The US Justice Department has opened a criminal investigation into Ford Motor Co.'s emissions certification process, the automaker disclosed two months after fessing up to an issue with its testing.
Ford is fully cooperating with all government agencies, the automaker said Friday in a regulatory filing.
The company said that because the matter is still at a preliminary stage, it can't predict the outcome or assure investors it won't have a material impact.
Ford revealed in February that it had been taking a flawed approach to using road-load specifications to simulate how aerodynamic drag and tire friction can affect fuel economy outside testing labs. It hired an outside firm earlier this year to help conduct an investigation that could stretch into the summer.
Ford shares pared their advance in pre-market trading following a better-than-expected earnings report Thursday. The stock was up 7.3% to $10.09 as of 8:45 a.m. Friday in New York after climbing as much as 9% earlier.