Toyota Motor Corp. may add the Corolla, the world’s top-selling car, to a record recall list after U.S. regulators began investigating the vehicle’s power steering.

The National Highway Traffic Safety Administration inquiry will cover about 500,000 vehicles from model years 2009 and 2010, a person familiar with the matter said. Toyota is reviewing the Corolla’s steering and will recall the car if there is a safety issue, Executive Vice President Shinichi Sasaki told reporters, after the NHTSA received more than 80 online complaints.

A Corolla recall would add to a repair list of more than 8 million vehicles on five continents spanning models from the Camry sedan to the Prius hybrid. Toyota, the world’s largest carmaker, has lost more than $31 billion in market value since announcing fixes for accelerator-pedal defects on 21 January 21.

“Toyota’s troubles are going to continue for a while,” said Mamoru Kato, an analyst at Tokai Tokyo Research Centre in Nagoya, Japan. “Customer complaints will just snowball because they are related to driver perceptions.”

“We are aware of complaints regarding 2009 and 2010 Corolla steering systems, are investigating the issue and will cooperate fully,” with NHTSA’s investigation, Cindy Knight, a Toyota spokeswoman, said in an e-mailed message.

President Akio Toyoda said the company is making progress addressing the recalls, and that dealers in Japan will have fixed as much of 80 per cent of Priuses by the end of February.

Toyoda said he plans to skip testifying before the U.S. Congress about the company’s recalls and hasn’t decided on his schedule for a U.S. visit. North American President Yoshimi Inaba will attend hearings in Washington next week, Toyoda said. Toyota’s U.S. sales unit president Jim Lentz will testify at the first U.S. house hearing on the recalls, according to the company.