Nissan has announced that it will recall an additional 150,000 vehicles in Japan due to improper testing being carried out during final inspections.

The automaker said via a press statement that it had found several non-conformities that may have caused inaccurate pass/fail judgments during the inspection process, which were related to brakes, the steering and speed-related measurements.

The recall was prompted following cases of misconduct being uncovered during on-site checks by regulators at a major Nissan plant. It was reported that several employees admitted to the regulators that they had not been following protocol in tests.

Nissan said the issue resulted from ambiguity regarding final vehicle inspection procedures and a lack of understanding of non-compliant practices.

The automaker revealed that the vehicles involved in the recall were produced at the Oppama and Auto Works Kyoto production plants. Models that are set to be recalled include the Note, second-generation Leaf, Juke, Cube and Sylphy, all produced for the domestic market.

This is the fourth time Nissan is reporting such misconduct since the issue broke in September last year, leading it to recall over one million vehicles sold in Japan. Then, in July, the company admitted to improper emissions and fuel economy testing on 19 of its models – including the Note and the Juke – sold in Japan.