Automotive News reports Toyota may have known about the problem behind the company’s recall of 7.43 million vehicles. The recall covers faulty window switches that may get stuck or catch fire if improperly lubricated. The National Highway Traffic Safety Administration received its first complaint about the issue some four years ago, which singled out American supplier, Tram Inc., and its Japanese parent company, Tokai Rika Co., as being to blame for the trouble. The faulty switches in question were described as emitting a strange smell and were sent back to the supplier for analysis. Tokai Rika couldn’t discern a cause for the failure.

Funk Flex

Toyota dropped the case in that instance, but continued to monitor the switches. Similar reports flared up once again in 2010, this time with the components actually smoking, and Toyota launched a full-fledged internal investigation that eventually led to the recent recall. The campaign covers nearly 2.5 million vehicles in the US alone.

Why did it take Toyota so long to launch the recall? The company says it was trying to discern why the switches were failing before it issued a fix.