Nissan is recalling five of its 2013 models in the U.S. because a faulty sensor can permanently turn off the front-seat passenger air bag.

The recall covers the Altima midsize car, as well as the Leaf electric car, Pathfinder SUV and the Sentra compact. Also covered is the Infiniti JX35 SUV.

The Altima is Nissan's top-selling car with 49,000 sold this year.

Nissan says in documents filed with safety regulators that it hasn't determined the number of vehicles affected by the recall.

Front passenger seats have sensors that determine the passenger's weight and turn off air bags off if a child is on board. The malfunctioning sensors can turn the air bags off permanently.

Nissan says its dealers will inspect the sensors in April and replace them free of charge if necessary.