WASHINGTON — Toyota first learned in 2008 about a defect in power-window switches that Wednesday prompted it to recall 7.43 million vehicles worldwide for fire hazards, according to documents filed with US regulators.
Toyota, based in Toyota City, Japan, received a report in September 2008 from the United States about an unusual smell from the power-window master switch and thermal damage to the switch, the company said in a report posted Thursday on the National Highway Traffic Safety Administration website.
The automaker sent the part to the supplier to investigate and no root cause was found. No other problems with the switch were reported until May 2010, when the company said it began sporadically receiving information about an abnormal smell or smoke coming from driver’s side doors, according to the report.
‘‘There was really no trend early on, and it took considerable time to diagnose what seemed to be an isolated problem and how it was occurring,’’ John Hanson, a US spokesman for Toyota, said in an e-mail.
In 2009 and 2010, Toyota, Asia’s biggest carmaker, recalled a record number of vehicles worldwide for defects that may cause unintended acceleration. The company in April 2010 agreed to pay a record $16.4 million US fine for failing to promptly report the flaws with vehicle accelerator pedals.
‘‘I’m a little disappointed in that Toyota didn’t act sooner especially because of the debacle in 2010 and, more importantly, the tragedy in 2010,’’ said Rebecca Lindland, an analyst with IHS Automotive, referring to deaths that occurred due to unintended acceleration. ‘‘It’s not surprising that they would delay given their pattern of resisting recalls historically.’’
The US auto-safety regulator opened an investigation into about 830,000 Camry cars and RAV4 crossover sport utility vehicles in February after receiving six reports of fires that started in the window switch. It has received reports of nine injuries and 161 fires.