A proposed nationwide class action lawsuit has been filed against Ford Motor Co. over defects associated with the interactive touch-screen display systems in its Ford, Lincoln and Mercury vehicles.

The MyFord Touch system, launched in 2010, was designed to seamlessly operate audio controls, global positioning system navigation and climate controls, as well as a Bluetooth device. But Ford chief executive officer Alan Mulally acknowledged that the system has had technology problems. The defect has caused Ford to plummet in rankings by J.D. Power & Associates and Consumer Reports.