Nissan admitted to improperly measured exhaust emissions and fuel economy testing for 19 of its models sold in Japan, according to Reuters. Sample test environments for emissions and fuel economy during final vehicle inspections had been found to be not in line with Japanese domestic standards, and inspection reports were based on altered measurements, it said.

The latest findings concerning the Japanese automaker does not affect vehicles exported overseas as these apply to requirements intended specifically for the Japanese market, the company said. It had suspended vehicle production in Japan last October in order to address the inspections misconduct, and announced that production will resume the following month.

The issue was found during voluntary compliance inspections which followed the inspection scandal last year, and affected models such as the Note and the Juke. Out of approximately 2,200 sample tests performed at six plants, 1,200 units at five locations were found to have some form of falsification, according to Nissan.

The findings included incidents in which vehicle driving speeds, durations and external temperatures were not in line with testing regulations, while testing equipment was also found to have not been calibrated properly, the report added. However, recalls were not necessary as the findings did not compromise the safety of the affected models, and mileage readings were in line with levels presented in catalogues, said Nissan.

Currently available data showed that tampering incidents dated back to 2013 and involved 10 employees, though it is possible that older data could mean the problem dates back even further, said chief operating officer Yasuhiro Yamauchi. The use of uncertified inspectors was blamed on staffing shortages, and work by the uncertified staff continued even after the issue first came to light in September.

Nissan’s compatriots Subaru and Mitsubishi were also found to fall foul of emissions and efficiency ratings, and fuel efficiency ratings, respectively, in a difficult period for the ‘Made in Japan’ reputation that also saw the Kobe Steel data scandal come to light.