She explained the expansion of the ignition switch recall in a statement Friday, noting faulty switches could have been installed as a repair after owners purchased one of the newer models
"Trying to locate several thousand switches in a population of 2.2 million vehicles and distributed to thousands of retailers isn't practical," Barra said. "Out of an abundance of caution, we are recalling the rest of the model years."
She added: "We are taking no chances with safety."
--CNNMoney's Chris Isidore, Katie Lobosco and Peter Valdes-Dapena contributed to this report.