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.

The National Highway Traffic Safety Administration has opened a pair of investigations into Ford practices surrounding certain recalls.

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.