This combination of photos shows clockwise from top left the logos for Toyota, Honda, Kia, Fiat Chrysler, Mitsubishi and Hyundai. U.S. auto safety regulators have expanded an investigation into malfunctioning air bag controls to include 12.3 million vehicles because the bags may not inflate in a crash.

This combination of photos shows clockwise from top left the logos for Toyota, Honda, Kia, Fiat Chrysler, Mitsubishi and Hyundai. U.S. auto safety regulators have expanded an investigation into malfunctioning air bag controls to include 12.3 million vehicles because the bags may not inflate in a crash.