June 25 (Reuters) - Ford Motor is recalling 552,188 of its 2014 F-150 vehicles in the U.S., due to an issue which may lead the vehicle to unexpectedly downshift into the first gear, the National Highway Traffic Safety Administration said on Tuesday.

A loss of signal between the transmission output shaft speed sensor and the powertrain control module can cause a downshift, regardless of vehicle speed and lead to a loss of vehicle control, the regulator said.

As a remedy, dealers will update the powertrain control module software, free of charge. (Reporting by Gursimran Kaur and Shivansh Tiwary in Bengaluru; Editing by Rashmi Aich and Mrigank Dhaniwala)