DETROIT – The Justice Department has opened a criminal investigation into Ford's U.S. emissions certification process.
Ford said in a regulatory filing the “matter currently focuses on issues relating to road load estimations, including analytical modeling and coastdown testing.”
In February, Ford launched an investigation into whether it overstated gas mileage and understated emissions from a wide range of vehicles.
Auto analyst John German said Ford developed a coast-down test that can be applied to all of its vehicles, since testing every single vehicle isn't cost-effective.
"They develop models of how adjustments can be made based upon other inputs and there's something in the models that isn't, maybe not quite right," German said.
In the grand scheme of things the situation isn't expected to be anything sinister like the Volkswagen fuel economy scandal.
Watch the video above for Jason Colthorp's full report.