The vehicles were produced between 2005 and 2014 in all markets except Japan, where the recall affects models as recent as 2016.
Toyota said it had traced the problem to its design of metal seat-cushion frames in the S.U.V.’s rear seats. In a severe frontal crash, it said, the frames could slice through the belts, leaving passengers unrestrained. It said that the seatbelts themselves were safe and that the problem was not caused by a supplier. That is a contrast to another recent problem involving auto safety devices, the extensive recall of vehicles equipped with defective airbags produced by the Japanese manufacturer Takata. Toyota said its dealers would fix the problem in the RAV4s by adding resin covers to the metal seat-cushion frames. That will take 30 minutes to 60 minutes per vehicle. “The condition does not occur in other vehicles, because the shape of the metal seat-cushion frame is different,” Toyota added. Automakers have become extra sensitive to safety equipment faults after the airbag recalls, the largest in industry history. Ten deaths and more than 100 injuries have been linked to the defect. So far, 14 automakers have recalled 28 million airbag inflaters — the metal casing that contains the propellant — in about 24 million vehicles. Last week, automakers including Honda and Fiat Chrysler recalled about five million vehicles worldwide to fix a defect in an airbag component made by another manufacturer, Continental Automotive Systems. Echoing the Takata fiasco, Continental, a German supplier that manufactures electronic airbag-control parts, had been aware of a defect in some units since January 2008, according to a filing with federal safety regulators made public on Thursday.