TOKYO (AP) — Toyota Chairman Akio Toyoda has apologized for massive cheating on certification tests for seven vehicle models.

The fraudulent testing at Japan’s top automaker involved the use of inadequate or outdated data in collision tests and incorrect testing of airbag inflation and rear-seat damage in crashes.

Engine tests were also found to be falsified.

Toyota stopped production Monday of the three models made in Japan.

The deceptive tests don’t affect the safety of the vehicles already on roads.

Two other Japanese automakers Mazda and and Honda also reported Monday improper testing of their vehicles but said they are safe to use.