The U.S. government has filed a civil lawsuit accusing FiatChrysler Automobiles NV of using software to bypass emission controls in diesel vehicles. The U.S. Justice Department suit, filed in U.S. District court in Detroit, is a procedural step that may ramp up pressure on Fiat Chrysler. The suit could ultimately help lead to a settlement, as in an earlier probe of rival Volkswagen AG that will cost VW up to $25 billion, but which affected a much larger number of vehicles. VW admitted to intentionally cheating while Fiat Chrysler denies wrongdoing.