According to Ford, this is due to the risk of fire that could result from using these cords. “Using the 120-volt convenience charge cord originally provided with the affected vehicles with an AC outlet that is not on a dedicated circuit or is damaged, worn or corroded may result in increased temperature at the wall outlet and potentially lead to a fire.”
However the good news is that this doesn’t appear to affect all of Ford’s hybrids and EVs. Instead according to Ford, this will be applicable to “select 2012-15 Ford Focus Electric, 2013-15 Ford Fusion Energi and 2013-15 Ford C-MAX Energi vehicles”, and it is expected that about 50,000 customers and owners will be affected as a result of this.
Apart from this announcement, Ford will also be notifying customers by mail, and are also instructing customers who might be affected by this to take their vehicles to a Ford dealer and have the charge cord replaced with the latest version for free. The new version will come with a thermistor and will be able to detect when it gets too hot, in which charging will be discontinued until temperatures fall back down to safer levels.