WASHINGTON/DETROIT (Reuters) – Volkswagen AG (VOWG_p.DE) faces penalties up to $18 billion after being accused of designing software for diesel cars that deceives regulators measuring toxic emissions, the U.S. Environmental Protection Agency said on Friday. “Put simply, these cars contained software that turns off emissions controls when driving normally and turns them on when the car is undergoing an emissions test,” Cynthia Giles, an enforcement officer at the EPA, told reporters in a teleconference.