NEW YORK — Toyota is recalling 670,000 of its 2004-2009 Prius hybrids in the United States to fix problems involving the loss of steering and the hybrid powertrain shutting down, the automaker has told the National Highway Traffic Safety Administration.
The move is part of a worldwide recall of almost 2.78 million vehicles, according to the Associated Press, which quoted Toyota officials in Japan. Only the Prius is affected in the United States. Outside the United States, the recall covers the Corolla and the Wish, a small van.
The cars are being recalled because the metal used for a steering component is not hard enough, according to a report the automaker filed Wednesday with the safety agency. The part could wear out ‘‘if the steering wheel is frequently and forcefully turned to the full left or full right position while driving at low speeds,’’ and that ‘‘could result in the loss of steering ability,’’ according to the report.
Toyota said it got its first notice of such a failure in February 2010 in Japan and began an investigation that was inconclusive. In February 2012, Toyota got its first report of steering loss in the United States. This month, the company said that it finally knew the cause and decided a recall was needed.
A second recall covers 350,000 of those same vehicles and involves replacing an electric water pump that could fail and shut down the hybrid powertrain system. But the gas engine would continue to move the vehicle, a Toyota spokesman said.
Toyota told the agency it got its first report of a water pump problem in 2009 in Japan, which resulted in changes to the pump in 2010. But pump failures continued, and it was not until this month that Toyota determined the cause of the problem: a coil wire that could be scratched, leading to corrosion.
This is the second time the automaker has experienced a cooling problem on the Prius hybrid system.
In 2010, the company conducted what it called a customer satisfaction campaign that covered 2004-2007 Priuses in North America. Toyota said it would replace the coolant pump because it could malfunction.