On vehicles equipped with automatic transmissions, the ignition park-shift interlock is the suspected culprit. A possible malfunction allows drivers to remove the key from the ignition even if the vehicle is not in Park. Vehicles have been said to roll away and collide with other objects.
Forty-three complaints, some apparently resulting in injuries, have triggered the agency's examination of approximately 577,000 vehicles. Honda says it will begin its own investigation into the matter as well.