Daihatsu Motor on Tuesday resumed production at its plant in Ikeda, Osaka Prefecture, after suspending operations from late December last year due to its safety test fraud scandal.

All of Daihatsu's four finished vehicle assembly plants in Japan are back online for the first time in about four months. The subsidiary of Toyota Motor will speed up the delayed delivery of vehicles for which it has received orders, as well as the improvement of existing models and the development of new models.

In February, Daihatsu, headquartered in Ikeda, started resuming production in stages for models confirmed safe by the transport ministry.

At the plant in Ikeda, the company will manufacture the Copen minivehicle and a model of the same name for Toyota.

"We've caused inconvenience for a very large number of people for a very long time," a male worker at the Daihatsu headquarters said on Tuesday morning. "Although we're still in the process of restoring trust, I think we've moved a step forward."

A Daihatsu public relations official said that the company will take thorough measures to prevent a recurrence.

Even after operations resumed at all of its domestic plants, Daihatsu's production is expected to be less than 80% of the level in fiscal 2022, before the company's safety testing irregularities were revealed, partly due to delays in the introduction of new models.

After the scandal came to light, Daihatsu hammered out prevention measures including an extension of product development periods and an increase in safety test personnel.

In an interview in late April, Daihatsu President Masahiro Inoue said that by surely implementing the prevention measures, the company aims to resume its development of new vehicle models within this year.