It includes a recall of the top selling Elantra and SUVs sold from the 2007 to 2011 model years, BBC News reported.
The recall - one of the largest the automakers have ever made - was announced Wednesday.
The company said it will need to repair a problem with a brake light switch that could increase the risk of a crash, the National Highway Traffic Safety Administration (NHTSA) said.
Another risk is a malfunction with the cruise control, the LA Times reported.
The Hyundai cars involved are 2007 through 2009 Accents and Tucsons, 2007 through 2010 Elantras, 2010 to 2011 Genesis Coupes, 2007 through 2011 Santa Fes, 2011 Sonatas and 2008 through 2009 Veracruzes.
The Kia models involved are 2011 Optimas, 2007 through 2010 Rondos and Sportages, 2007 Sedonas, 2007 to 2011 Sorentos and 2010 to 2011 Souls.
CNN reported Hyundai recalled cars in 2009 for a similar problem, which needed the brake light switch replaced.