A recall by Ford Motor Co. of over 250,000 Explorer SUVs in the United States is being investigated by the National Highway Traffic Safety Administration, after customers complained that repairs which were intended to address a possibility the vehicle would roll away while placed in park, caused their vehicles to behave erratically.

The initial problem was attributed to a rear axle mounting bolt which could fracture. That would cause the drive shaft to disconnect from the axle, which would allow the vehicle to roll freely, even while in park. The issue was addressed by Ford with a software update which would cause the vehicle to apply the electronic parking brake in the event the drive shaft failed. However two complaints have since been filed, alleging the SUVs began to behave erratically after the repairs were applied. In one case, the Explorer suddenly began applying the electronic parking brake while the vehicle was moving, bringing the vehicle to a sudden stop while traveling at speeds of up to 30 or 40 miles per hour.

The other complaint said the vehicle would lurch into motion as the driver sought to disengage the electronic parking brake.

Neither complaint had resulted in injuries, however the first driver noted they had struck a utility pole after the vehicle began rolling down a hill after an abrupt stop, seemingly due to the drivetrain being disengaged.

The original recall applied to specific 2020 through 2022 Ford Explorers with 2.3L engines, the 3L and 3.3L hybrids, and the 3L ST.  It also included the 2020 and 2021 Explorer Police hybrids, and vehicles with 3.3L gas engines. Both reported incidents involved 2021 Explorers.

In a statement a Ford representative noted the company is cooperating with the NHTSA on the investigation.