Mubasher: Nissan on Monday announced that it has uncovered falsified data from car exhaust emissions tests performed at all of its factories in Japan, except for its facility Nissan Motor Kyushu.

As Nissan has been performing full-scale compliance checks of its operations since September, the auto manufacturer found that the emissions and fuel economy tests had “deviated from the prescribed testing environment.”

The Yokohama-headquartered company said also inspection reports had been “based on altered measurement values.”

Nissan pledged to “carry out comprehensive checks of frameworks, organizations, and processes related to regulatory compliance,” and to take “appropriate measures” in the event of any future recurrence.

Despite the automaker has not specified the number of cars that were affected by the altering of data, it confirmed that all vehicles, except for its GT-R, are in conformity with Japanese safety standards, based upon “reliable” data.

Meanwhile, the Japanese carmaker has not revealed the reason of excluding GT-R.