DETROIT, USA (AP) — The largest recall in Toyota’s 75-year history could undermine the Japanese automaker’s comeback from natural disasters and embarrassing safety problems.

The company recalled 7.43 million cars, trucks and SUVs worldwide to fix faulty power window switches that can cause fires. Wednesday’s recall affects more than a dozen models produced from 2005 through 2010 including the Camry, the top-selling car in the US. It’s bigger than the 7 million vehicles recalled two years ago for floor mats that can trap accelerator pedals and cause unintended acceleration.

The problem centres on the power window switch, which is inside the driver’s door and controls when a window is opened or closed. Toyota said grease wasn’t applied evenly to the switch during production, causing friction and sometimes smoke and fire.

The flaw raises questions about whether Toyota Motor Corp has solved quality and safety issues that embarrassed the company in 2009 and 2010. It also could jeopardise Toyota’s impressive rebound from last year’s earthquake and tsunami in Japan. Those disasters hobbled factories and left dealers short of models to sell.

The Toyota recall “takes some of the sheen off its recovering brand image and should have a financial impact,” Standard & Poor’s analyst Efraim Levy wrote in a note to investors. Toyota’s US shares fell US$1.60, or 2.1 per cent, to US$74.46 Wednesday afternoon.

Toyota said initially the window switch problem hasn’t caused any crashes or injuries. But documents filed by US safety regulators show customers have reported 161 fires and nine injuries. No deaths have occurred.

The US National Highway Traffic Safety Administration (NHTSA) began looking into window switch problems with two Toyota models in February after noticing a higher than normal number of complaints. Most fires were minor, although one destroyed a Camry. Several owners reported that they were afraid to drive their vehicles because of the threat of fires. NHTSA said Wednesday that the investigation remains open pending a review of recall documents.

Toyota said Wednesday it has received more than 200 complaints about the switches in the US, and more from other countries including 39 in Japan. Most of the complaints were about a sticky feel to the switches while pushing the button to raise or lower the window, but there also were complaints of the smell of smoke, company spokesman John Hanson said.

Toyota dealers will inspect the switches and apply special grease to them. In some cases, the switches and circuit boards could be replaced, Hanson said. Some repair shops might have used off-the-shelf greases to fix the problem, but those eventually will make it worse, he said.