A Pennsylvania judge has reversed the involuntary manslaughter conviction of a woman after determining a faulty General Motors ignition switch contributed to her crashing into a school bus, killing her passenger boyfriend.

Twenty-five-year-old LaKisha Ward-Green, of Penn Hills, pleaded guilty to manslaughter and reckless driving in 2012. She served three months of a one- to two-year jail sentence before her attorney appealed citing the GM defect.

Police determined Ward-Green was driving 75 mph in a 35 mph zone when she crashed, killing 16-year-old Robert Chambers IV.

Allegheny County Judge Philip Ignelzi overturned the conviction on Wednesday.

Last year, GM recalled 2.6 million small cars like Ward-Green's Chevy Cobalt because the ignition switches could unexpectedly turn off, causing the cars to stall, disabling the air bags and power steering and brakes.