Nissan Motor Co. says it has altered results of exhaust emissions and fuel economy tests of its new vehicles sold in Japan, in the latest misconduct to surface at the Japanese automaker. Credit: Shuji Kajiyama | AP

Nissan Motor Co., the Japanese carmaker that was embroiled in a vehicle-inspection scandal last year, said it uncovered some instances of misconduct involving falsified data about exhaust emissions and fuel economy.

The data falsification, which occurred on 19 models across five plants in Japan, was found out when the company was carrying out an internal check about employees conducting final inspection of vehicles, Nissan said at its Yokohama headquarters Monday. The incident won’t lead to any recalls as the vehicles meet catalog specifications for fuel economy and emissions, according to the company.

Although the tests were not in line with Japanese government requirements, the incident — based on what has been disclosed — may not be as threatening as the emission scandal that engulfed Volkswagen. Testing of vehicle emissions rose to prominence globally after the European carmaker was caught fitting devices on its diesel vehicles that helped it overcome the standards. German authorities are still scrutinizing the automaker. Daimler is also under investigation, and both face lawsuits in Germany and the U.S.

During the checks, Nissan found out that employees misrepresented temperature and humidity data in the testing chamber and manipulated emission data on carbon monoxide and carbon dioxide. The automaker has hired a law firm to investigate the matter further.

Nissan’s announcement, following an inspection debacle that led to the recall of about 1.2 million vehicles last year, is the latest in a string of compliance scandals at carmakers including Mitsubishi and Subaru that has dented the reputation of Japan’s manufacturing sector.

Nissan dropped 4.6 percent in Tokyo, the largest decline since November 2016, before the company held a press conference Monday. The stock has lost 11 percent of its value this year.

Renault, which is the largest shareholder of Nissan, tumbled as much as 2.6 percent initially, before recouping some of those losses.

Hiroto Saikawa, 64, said last year he and other officials at the carmaker will take a voluntary pay cut after the car inspection crisis led to a vehicle recall in Japan and a reduction in its profit forecast. Nissan halted vehicle registrations in Japan after its inspection process was deemed faulty by the government.

Workers not authorized to certify vehicles approved the final inspection at the very end of assembly lines and that process may have dated back to 1979 at its Tochigi plant, according to a report last year from Nissan and a third-party law firm it assigned to investigate.

Last year, Kobe Steel Ltd. said it sold products that failed quality control tests to over 500 companies. Subaru, which admitted to manipulating emission data records to match mileage submitted to the government, was also embroiled in a similar controversy as Nissan’s. Yasuyuki Yoshinaga stepped down as Subaru CEO this year.

Nissan bailed out Mitsubishi Motors in 2016 after the company was caught falsifying mileage estimates for several of its vehicles. Suzuki Motor Corp. Chairman Osamu Suzuki ceded the role of CEO after the automaker admitted to using unapproved fuel-economy testing methods in 2016.

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