Subaru is recalling about 48,500 2015-17 Outback and 2016-17 Legacy models because the steering may fail, the automaker told federal regulators on Thursday.

Outback is Subaru’s second-best-selling vehicle; about 140,000 were sold last year.

The carmaker said that because the steering column in affected vehicles may have been improperly built, turning the steering wheel may have no effect on the direction of the wheels. It warned owners not to drive the vehicles until they were inspected or repaired.

The automaker said it began an investigation on May 3 after an Outback owner reported “an issue” with the steering, according to a report on the website of the National Highway Traffic Safety Administration.

Subaru said a week later it had determined a recall was necessary. It said an “incorrect setting” of a tool making a steering part could allow the steering wheel “to rotate freely,” leading a driver to “lose the ability to steer the vehicle.”