The official notice
Defect
On certain vehicles, a problem inside the high-voltage battery could cause a short circuit. If this happens, there could be a loss of power to the wheels and/or the high-voltage battery could overheat. Note: This recall only affects certain plug-in hybrid vehicles (PHEV) equipped with a 2.5 L engine.
Safety Risk
A loss of power to the wheels could increase the risk of a crash. A battery that overheats can create a fire risk, even while the vehicle is parked and turned off.
Remedy
To reduce the safety risk, Ford advises not to charge your vehicle until the recall repairs have been completed. Ford will notify owners by mail and advise you to take your vehicle to a dealership to update the battery energy control module (BECM) software. The software will monitor the high-voltage battery and warn you if it detects a problem. If you see this warning, you should contact a dealership to arrange replacement of the high-voltage battery pack.