Toyota spokeswoman Shino Yamada said that five incidents of malfunctions have been reported, though there were no accidents or injuries.
In the United States, vehicles involved include certain Toyota Corolla, Corolla Matrix, Sequoia, and Tundra, and Lexus SC 430 models manufactured from 2001–2003, according to a statement from Toyota Motor Sales USA Inc. in California.
"More precise vehicle information is being developed, but about 510,000 vehicles may have to be inspected to locate the suspect inflators," the company said.
For Toyota, it's the second time this year that the company has announced a recall involving more than 1 million vehicles. Toyota said in January it will recall nearly 1.3 million cars globally for two separate defects, including 752,000 Corolla and Corolla Matrix vehicles in the United States to fix airbags that could be deployed inadvertently. U.S. supplier TRW Automotive manufactured the airbag control unit in the vehicles, although a problematic chip in the airbags was supplied by another company, Reuters reported.
Last year, Toyota announced a recall involving 7.43 million units in October, followed by one involving 2.77 million vehicles the next month.
Dating back to 2011
Takata said it learned of the problem from an automaker it did not identify in October 2011 after an airbag deployment in Japan. It learned of a Honda accident in Puerto Rico the following month, according to documents filed with U.S. safety regulators.
From February 2012 through June last year, Takata could not reproduce the problem in testing, but in autumn the supplier was alerted to three additional incidents -- two in Puerto Rico and one in Maryland -- according to documents filed with the U.S. National Highway Traffic Safety Administration.
By October 2012, Takata concluded it was possible that the propellant in certain wafers made at its plant in Moses Lake, Wash., might be inadequately compressed, which could lead to the rupture, according to NHTSA documents.
By March this year, it also discovered that some wafers used in inflators made at a plant in Monclova, Mexico, for a year ending in late October 2002 may have been exposed to excess moisture, which could lead to a rupture, according to documents filed with NHTSA.
Takata is aware of only six cases where an inflator ruptured in vehicles in the field -- four in the United States and two in Japan -- as well as six cases in salvage yards in Japan, according to NHTSA documents.
In July and August 2012 in Japan, at scrap yards where airbags were being recycled, officials noted that airbags in some Honda vehicles deployed "strangely," adding to the probe, a U.S. spokesman for Honda said.
Industry officials said the elapsed time between the first report of a problem and the announcement of the recall was not unusual because companies typically search for patterns and possible causes of problems before launching a recall.
Toyota said in NHTSA documents that it also received a report in October 2011 about an accident in Japan related to the issue. The automaker then asked Takata to investigate, but through August 2011 no abnormalities were found with 66 recovered inflators.
In September 2012, Toyota said it received reports of three vehicles in the U.S. market with fractured inflators, and the automaker asked Takata to study 144 parts that were recovered.
In February 2013, Takata said the inflators were cracked, possibly because of lower material density increasing pressure on the part, so Toyota asked the supplier to determine if a trend was developing, according to NHTSA documents. On April 5, Toyota decided to conduct its recall, three days after Takata said certain inflators could be faulty.
In Honda's case, between 2008 and 2011, the company was forced to recall about 2.8 million vehicles after finding a defect with driver-side airbags supplied by Takata.
"When the last recall took place, we inspected everything such as the site of manufacturing, but we were not able to identify this problem," said Hideyuki Matsumoto, a spokesman for Takata.
Global risks
This recall underscores the risk of huge global supply chain problems as automakers increasingly rely on a handful of suppliers for common or similar parts to cut costs.
Paul Newton, an analyst with IHS Automotive, said the fact that no serious crashes or injuries have been connected to the defect means there should be little damage to the affected carmakers' public image.
But at the same time, the "huge" number of vehicles involved will create "a good deal of unwelcome attention, particularly for Toyota as it strives to rebuild its reputation for quality in North America," Newton wrote in a report (see full text below).
Some airbags at the front passenger seat may not inflate correctly because of a problem with the propellant used in the airbag inflator, Toyota spokesman Ryo Sakai said.
Takata has also supplied the faulty airbags to non-Japanese carmakers, said Toyohiro Hishikawa, spokesman for the components maker, declining to identify them. Takata supplies airbags and seatbelts to major automakers including Ford Motor Co. and Daimler AG, as well as the Japanese brands.
The defect was caused by problems in the manufacturing process, Matsumoto said.
Some non-Japanese automakers were also supplied with the faulty airbags, a Takata spokesman said. He declined to name those automakers.
General Motors Co. said Takata is a supplier, but that the problem affected only about 55,000 Pontiac Vibe cars from model year 2003 built for the U.S. and Canadian markets. The cars were assembled at the Fremont, Calif., plant GM previously ran in a joint venture with Toyota and were included in Toyota's total recall number, a GM spokesman said. GM dealers will service its cars.
BMW has an undetermined number of vehicles affected by the recall, a U.S. spokesman for Takata said.
Officials with Chrysler, Daimler, Ford, PSA Peugeot Citroen , Renault SA and Volkswagen AG said they were not affected because they did not use the airbags covered by the recall.
The Takata U.S. spokesman said no other customers were affected.
Fire risk
Toyota said there was a risk of fires starting or passengers being injured because of the flawed inflators.
Toyota will exchange the faulty inflators for new ones, a fix that is expected to take about an hour to two-and-a-half hours for most models, Sakai said. He declined to give the costs related to the recall.
"The inflators themselves are not so expensive, but there is the cost to cover for the hours spent to fix the problem," said Kohei Takahashi, an autos analyst at J.P. Morgan in Japan.
Bloomberg, Nick Bunkley and Philip Nussel contributed to this report.
