The recent cheating scandal of Kobe has underscored the deepening crisis at the steelmaker and the sweep of quality problems besetting Japan's manufacturing sector.
"Made in Japan" used to mean reliable quality, but the positive connotation has been dealt a severe blow in recent years after a run of various product scandals, with Kobe Steel the latest culprit.
Japan's third-largest steelmaker admitted last week it had falsified data about the quality of aluminum and copper products used in cars, aircraft, space rockets and defense equipment. Its chief executive Hiroya Kawasaki told reporters the scandal had left Kobe's credibility at "zero", underscoring the deepening crisis at the steelmaker and the sweep of quality problems besetting Japan's manufacturing sector.
Kobe Steel is one of Japan's biggest producers of aluminum automotive panels and supplies parts to almost all the Japanese carmakers.
Toyota said it was working to identify which auto models might be affected and what impact there might be on individual vehicles.
It told news agency Bloomberg that the materials were supplied to plants in Japan and factories elsewhere weren't affected.
Nissan, Subaru, Mazda and Mitsubishi are checking whether their models are affected.
The scandal broke out as the sales of Japanese cars rose in China, which many believe will more or less erode customers' trust in Japanese manufacturers.
Statistics from the China Association of Automobile Manufacturers show that Japanese cars had a 17.8 percent market share in China by the end of September, 2 percentage points higher than the same period last year. The victims are not only Japanese carmakers. According to data compiled by Bloomberg, its top customers include United States industry titans GM and Ford. "General Motors is aware of the reports of material deviation in Kobe Steel copper and aluminum products," company spokesman Nick Richards told Reuters.
"We are investigating any potential impact and do not have any additional comments at this time."
It is not the first time that Japanese automotive parts suppliers have negatively impacted the global car industry.
Japanese airbag producer Takata Corp forced scores of automakers to recall tens of millions of cars worldwide equipped with its airbags.
It turned out that its faulty airbags could explode, and such incidents reportedly killed 17 people and injured more.
In China alone, some 20 million cars are equipped with Takata airbags, according to the General Administration of Quality Supervision, Inspection and Quarantine.
Japanese carmakers have been frequently discovered to be engaged in wrongdoing in recent years.
Earlier this month, Nissan was forced to announce that it was recalling 1.16 million vehicles that underwent a flawed safety inspection.
The carmaker admitted that it employed a large number of uncertified personnel for the safety inspection of its products.
Last year, Suzuki, the second-largest Japanese manufacturer of light vehicles, admitted that it had falsified fuel-economy data on 16 types of vehicles sold in Japan, involving over 2.1 million vehicles. Also in 2016, Mitsubishi Motors admitted that it had manipulated fuel-economy tests, which involved some 600,000 vehicles.
"If you look at the other previous incidents like this, whether it be Takata or Toshiba, despite companies initially saying it is a single one off, it has always expanded to involving more and more parts of the business," said Alexander Robert Medd, managing director at Bucephalus Research Partnership in Hong Kong.
"And one usually finds out that it is reasonably systematic," he told Bloomberg.