Tesla faces a new investigation by the National Highway Traffic Safety Administration, or NHTSA, concerning issues with its “Full Self-Driving” systems, and whether they are safe to use in fog, glaring sun or other “reduced roadway visibility conditions.

Driving” mode is being investigated by U.S. authorities following a series of crashes, including one accident that killed a pedestrian.

DETROIT (AP) — The U.S. government’s road safety agency is investigating Tesla’s “Full Self-Driving” system after getting reports of crashes in low-visibility conditions, including one that killed a pedestrian.