Due to a shortage of parts from Japan, the Toyota Motor Company will halt production at its North American factories.Spokesperson Tania Saldana says the plants will remain open, but will not produce vehicles. Workers will not be laid off and may either show up for work and go through additional training or take vacation or unpaid time off. She says it hasn't yet been decided how long the shutdowns will last or whether all of the automaker's North American plants will stop producing vehicles.Toyota employs about 25,000 workers at more than a dozen factories in North America, including facilities in Kentucky and Indiana.About 15% of the parts used in those plants come from Japan.