TOKYO -- Toyota Motor Corp.'s global recall of 7.43 million vehicles to fix power-window switches traces back to a 2008 complaint in the United States and pins blame on an American supplier and its Japanese parent.
According to Toyota documents filed this week with the National Highway Traffic Safety Administration, the first field report indicating a problem was received by Toyota in September 2008. It cited an unusual smell coming from the power-window switch as well as heat damage.
The part was returned to the supplier for examination, but no root cause could be determined, Toyota said in an Oct. 10 filing with NHTSA.
Toyota dropped the case but continued to monitor the situation.
But by May 2010, similar reports again began popping up -- this time with the controls smoking. Toyota immediately stepped up an internal investigation.
The problem was sticky driver's-side switches made by Japan's Tokai Rika Co. and its U.S. subsidiary, Tram Inc. of Plymouth, Mich., Toyota disclosed in the NHTSA filing.
Some of the parts were made in the United States and Japan. But the automaker has since said that defective components were also manufactured in Thailand and China.
Some 2.47 million vehicles -- about a third of the worldwide tally -- were recalled in the United States. About 1.4 million vehicles in China and 1.39 million in Europe are also affected by the recall, with hundreds of thousands elsewhere.
In the United States, the recall covers various 2007 through 2009 models of the Camry, Camry Hybrid, Yaris, RAV4, Tundra, Scion xD, Scion xA, Sequoia, Highlander, Highlander Hybrid, Corolla and Matrix.
In February, NHTSA began investigating Toyota Camry sedans and RAV4 crossovers from the 2007 model year after owner reports of door fires. NHTSA later expanded the probe to cover 2007 to 2009 Camry, Camry Hybrid, RAV4 and Yaris models.
In announcing the recall, Toyota said the window-switch problem hadn't caused any injuries. Media reports later said documents filed with U.S. safety regulators showed customers reported 161 fires and nine injuries. Those fires and injuries were disclosed as part of NHTSA's investigation launched in February.
There have been no crashes or deaths.
Toyota spokesman Keisuke Kirimoto told The Associated Press the public relations staff that handled the recall announcement wasn't aware of the nine injuries reported to NHTSA. He called the error embarrassing but honest.
Biggest recall of single part
It's the biggest recall of a single component by Toyota, the automaker says. The recall of 7.7 million floormats that began in 2009 to address unintended acceleration covered a range of different mats.
According to a report posted on NHTSA’s website, the driver of a 2007 Camry reported noticing “black smoke throughout the car” that “immediately turned into flames, which caused poor visibility and complete panic” for the driver and three passengers in the car on Dec. 26, 2011. The flames burned the driver’s coat and a passenger’s hand as he tried to put it out.
“It was a frightening experience for myself and family members as I strongly feel that no one has a clear explanation as to the cause of the fire and fails to ensure my family’s safety and well being,” the driver wrote in the report.
The years-long probe that led to this week's recall evokes the massive unintended acceleration recalls Toyota endured two years ago. At that time, Toyota was criticized for its slow response to the reported problems. It prompted the company to pledge to streamline its troubleshooting to remedy glitches faster.
But the filing this week with NHTSA shows how Toyota officials in Japan and North America continue to grapple with identifying and responding to potential safety issues in a timely matter.
"We are not proud of recalls. But there is nothing wrong with recalls per se. Hiding anything would be the problem," Shigeru Hayakawa, a senior executive, told the AP Thursday in Tokyo. "We are dealing with problems more expediently."
Another Toyota spokesman declined to comment beyond the NHTSA filing but reiterated it only discovered a cause for the power-window switch problem recently.
"We were trying to identify the reason," Toyota spokesman Joichi Tachikawa said. "We can't announce it until we really identify what's going on and determine the root cause."
He also declined to identify the supplier or comment on the supplier's response.
Tokai Rika declined comment and referred all inquires back to Toyota
"We are only a parts supplier, so we can't make any comment," spokesman Hitoshi Asano said.
NHTSA spokeswoman Lynda Tran said the agency will continue to monitor the recall.
“NHTSA is aware of the recall announced by Toyota yesterday and is in contact with the manufacturer,” Tran said in an e-mail. “The agency’s investigation remains open pending its review of Toyota’s documents regarding its recall action.”
After Toyota determined the cause in August 2012, following years of repeated testing, the NHTSA filing shows the company decided to conduct only a customer satisfaction campaign, not a full recall, because the overheating -- in Toyota's judgment -- was being triggered by "external factors."
The problem: Service technicians were applying over-the-counter lubricants to the switch in an attempt to get rid of the notchy or sticky feel, Toyota said in the filing. But the lubricants were a fire hazard.
NHTSA, however, had other ideas. In Toyota's filing, the company said that it decided on a recall on Oct. 4 after consulting with the federal safety agency. Notifications will be sent to owners later this month.
The root cause of the notchy controls appears to stem from internal factors, not external, Toyota suggested in the filing. Toyota traced the problem to a change in the manufacturing process at Tokai Rika. Between 2006-2008, the supplier switched the way it applied grease to the switches.
Previously, the supplier used a spray-type application. But it switched to a squeeze-type application, Toyota said in the NHTSA filing.
The squeeze-type process, however, had a tendency to apply the grease unevenly on the sliding contact module terminal inside the switch. Over time, this caused the grease to carbonize and wear prematurely -- leading to the sticky switch feel.
Starting in July 2008, the supplier again changed its greasing method to address the problem, a Toyota spokesman said. But it wasn't until May 2010 that the problem was universally addressed in switches going to all markets worldwide.
Bloomberg contributed to this report