How Toyota misjudged a big defect
Overheating switch initially downplayed
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TOKYO -- After months of sleuthing to pinpoint the cause of mysterious fires in power-window switches, Toyota Motor Corp. reached a curious conclusion: The problem presented no safety risk.
Of the handful of injuries reported, the worst amounted to little more than a blister on the index finger of the left hand.
In an April 5 filing to the National Highway Traffic Safety Administration, Toyota downplayed the risks of the switch glitch. And the company blamed the switches' overheating on service people who had been applying improper lubricants, despite being warned not to use such flammable compounds.
"Based on this review, Toyota believes that no defect trend is evident and no unreasonable risk to safety is presented," Toyota said of the switch fires in its filing to the agency.
Just six months later, Toyota changed its tune.
On Oct. 10, the switch problems morphed into the company's biggest-ever single component recall, forcing Toyota to call back 7.43 million vehicles worldwide. About 2.52 million, or a third of the global tally, were recalled in the United States.
What happened between April and October is not entirely clear from the documents. But the NHTSA filings show how Toyota officials continue to grapple with identifying and responding to potential safety issues.
In April, Toyota had reported 129 fires and eight injuries to NHTSA. NHTSA, adding complaints filed directly to the agency, compiled a list of 161 fires and nine injuries.
By August, Toyota had decided to address the problem through a "customer satisfaction campaign," not a full recall. But, Toyota said in its Oct. 10 recall notice, it decided on a full recall "after discussion and consultation" with NHTSA.
The recall evokes the crisis of 2009-10, when Toyota recalled 10 million vehicles for defects associated with unintended acceleration. Toyota was criticized for its slow response to the reported problems.
Now Asia's largest carmaker again finds itself in an unwanted spotlight, just as it recovers from last year's earthquake in Japan and deals with this year's anti-Japan consumer backlash in China.
After the 2009-10 unintended acceleration recalls, Toyota pledged to streamline its troubleshooting to remedy glitches faster. Toyota says those lessons were implemented in the latest recall but concedes that it takes time to find the right fix.
A trail of preliminary evaluation and engineering analysis reports traded between Toyota and NHTSA, dating to Feb. 17, 2012, show Toyota was cooperating with the agency to root out the problem, a Toyota spokesman said.
"It shows we were in a dialogue with NHTSA. We weren't hiding anything," he said. "Once our people got to the bottom of the problem, they were very fast in implementing a response."
Toyota conducted more than 200 tests to replicate the problem, he said, until engineers figured out that household lubricants were at play.
Toyota recovered and tested 56 suspect switches from the affected vehicles. The investigation eventually led to subjecting each part to infrared spectroscopic analysis to scan for any chemicals possibly tainting the parts.
What they found were traces of silicone and ester -- compounds not used in the manufacturing process but common in household lubricants. Engineers deduced that people were using the lubricants to treat switches that had become sticky with wear.
The first signs of trouble appeared four years earlier, in 2008, when a U.S. customer complained of an unusual smell coming from the power-window switch, as well as heat-related damage.
The part was returned to the supplier for examination, but no root cause could be determined, Toyota said in a NHTSA filing. Toyota dropped the case but continued to monitor the situation.
But by May 2010, similar reports again began popping up -- this time citing smoking controls.
Toyota immediately stepped up an internal investigation.
The problem was sticky driver's-side switches made by Tokai Rika Co. of Japan and its U.S. subsidiary, Tram Inc. of suburban Detroit, Toyota said in another NHTSA filing.
The defective parts were made in the United States, Japan, Thailand and China.
The recall covers various 2007-09 versions of the Toyota Camry, Camry Hybrid, Yaris, RAV4, Tundra, Sequoia, Highlander, Highlander Hybrid, Corolla and Matrix; and the Scion xD and xA and 2009 Pontiac Vibe built at a Toyota-GM plant.
Toyota says that the recall may look like a delayed reaction but that accurate troubleshooting takes time.
"We were trying to identify the reason," a second spokesman said. "We can't announce it until we really identify what's going on and determine the root cause."
You can reach Hans Greimel at hgreimel@crain.com. -- Follow Hans on 
