On Friday, vehicle owners in 14 states filed a class-action lawsuit on behalf of "potentially millions of purchasers and lessees of Ford vehicles manufactured between 2002 and 2010."
According to a statement from the plaintiffs, "Ford vehicles equipped with an electronic throttle control system are vulnerable to sudden unintended acceleration events."
"Ford has admitted that some of its vehicles are in fact prone to such acceleration," it said.
Ford's spokesman responded that "in rare situations, vehicle factors, such as floor mats or broken mechanical components, can interfere with proper throttle operation."
But he insisted that "manufacturers have addressed these rare events in field service actions."
In 2009, the world's largest automaker, Japan's Toyota, recalled around 10 million vehicles worldwide for a similar problem of unintended acceleration.
Once lauded for its safety standards, the defects and mass recalls tarnished the brand's image and hurt sales in 2010 and 2011.