An alleged drunken driver whose minivan crashed on the H-1 freeway in Aiea last year, killing one of his passengers and injuring five others, pleaded no contest in state court today to manslaughter and assault.

Kyer Valeros, 20, faces a maximum 20-year prison term for the manslaughter and five years for the assault at his sentencing in December.

Ervin Yanuara, 20, of Waipahu, died Feb. 4, 2011 after the Toyota Sienna Valeros was driving hit an embankment and flipped several times near the Kaonohi Street overpass.

Yanuara was the front-seat passenger. He and Valeros were thrown from the vehicle.

Five other passengers were injured.

The state says Valeros’s blood alcohol content was 0.17, more than twice the legal threshold for drunken driving, and that police estimate the van was traveling 90 mph when it hit the embankment.

Valeros was 19 years old at the time of the crash, too young to legally drink alcohol.