Four people were reportedly killed and another six injured. The agency said it was reviewing 425,000 2012-2013 Kia Forte and 2011 Hyundai Sonata cars.The NHTSA said the air bag control module was built by ZF Friedrichshafen-TRW, a German auto supplier that acquired TRW Automotive Holdings Corp in 2015. The agency says it also is looking into a 2016 recall involving Fiat Chrysler vehicles that had a similar problem causing the air bags not to deploy.Previously, on February, Hyundai Motor Co issued a recall last month for 154,753 U.S. Sonatas after non-deployment reports were linked to electrical overstress in the air bag control unit. The automaker said is working with the NHTSA in the investigation.
Hyundai does not yet have a fix for the problem but said it expects the Sonata recall to start April 20. The problem also can stop the seat belts from tightening before a crash. In May of last year, NHTSA opened an investigation into whether Hyundai and Kia moved quickly enough to recall more than 1.6 million cars and SUVs because the engines can stall, increasing the risk of a crash. Dealers will consider offering loaner cars to owners until the problem can be repaired, Hyundai spokesman Jim Trainor promised.