TOKYO (AP) — The U.S. Justice Department has reached a $ 1 billion settlement with Toyota Motor Corp., ending a four-year criminal investigation into the Japanese automaker's disclosure of safety problems.

The investigation focuses on whether Toyota was forthright in reporting quality problems related to unintended acceleration troubles.

Toyota says it's 'committed to continued improvement' to 'keep building trust.'

Starting in 2009, Toyota issued massive recalls, mostly in the U.S., totaling more than 10 million vehicles for various problems including faulty brakes, gas pedals and floor mats.

The Justice Department is also looking into whether U.S. automake General Motors Co. was slow in recalling cars with a defect linked to 13 deaths.