In February and March, GM recalled a combined 2.6 million Chevrolet Cobalts, Saturn Ions and other models fitted with the defective switches. The company faces a Justice Department probe, lawsuits tied to the faulty ignitions, and potentially billions of dollars in penalties and damages. On Tuesday, the National Highway Traffic Safety Administration, which is investigating whether GM followed requirements for timely recall of defective vehicles, fined GM for failing to respond to a request for information by an April 3 deadline. The NHTSA said GM may be fined up to $7,000 per day for each day it fails to provide the information, up to a maximum civil penalty of $35 million.