A U.S. government auto safety regulator has opened two separate investigations into Ford vehicles over concerns that prior safety recalls may not have been extensive enough. The National Highway Traffic Safety Administration (NHTSA) announced both probes, which collectively affect more than 500,000 Ford trucks and SUVs, on Nov. 15.

Just days after announcing a civil fine against Ford for moving too slowly on a recall, the U.S. government unveiled two investigations into recalls that may not have worked or covered enough vehicles.

Ford Motor Company was issued a civil penalty of $165 million for failing to comply with federal vehicle recall requirements.