Nissan has admitted that it has uncovered falsified data from car exhaust emissions tests at most of its Japanese factories.
The firm did not disclose how many cars were involved, but said emissions and fuel economy tests had “deviated from the prescribed testing environment”.
The carmaker added that inspection reports had been “based on altered measurement values”.
Nissan pledged there would be a “full and comprehensive investigation”.
It added that “appropriate measures” would be taken to stop any future recurrence.
Nissan has not revealed how many cars were involved in the altering of data, or if it involved vehicles manufactured outside Japan.
The company said it had rechecked “reliable” data and confirmed that all vehicles except the GT-R sports car conformed to Japanese safety standards. It did not explain why the GT-R had been excluded.
This is very embarrassing for Nissan and will damage its reputation, but it does not seem at the highest levels to have been deliberately trying to beat the system. Nissan appears to have been running its testing system very badly; they did not meet legal requirements and measurements were altered.
Nissan is still investigating what went wrong and so more details may emerge, although Nissan believes nearly all of its cars do pass emissions standards.