According to the article, the automaker discovered that models built before February 2nd may have front seat air bags that may fail to deploy in the event of an accident. Acadias and Outlooks built after February 2nd, apparently, either use a different bag or system since they are not part of the recall.
Approximately 13,000 SUVs have been recalled. GM urges owners to bring their vehicles back to their dealerships where they will be updated free of charge.