The recall, according to a report in Automotive News, comes after a US National Highway Traffic Safety Administration (NHTSA) investigation into why four people were killed and six injured in accidents where Hyundai and Kia airbags didn't deploy.
Hyundai USA recalled 579,000 vehicles to rectify reports of airbag non-deployment because of 'electrical over stress in the airbag control unit'. The company acknowledged, according to the report, two deaths in its cars, although it noted both were high-speed head-on accidents.
The Kia recall, announced on Friday in the USA, includes the 2010-13 Forte (Cerato), 2011-13 Optima, 2011-12 Optima Hybrid and 2011-12 Sedona. A fix hasn't yet been identified, but Kia says it's working with the supplier – ZF Friedrichshafen – to resolve the issue.
Fiat Chrysler recalled 1.4 million vehicles in the USA in 2016, after a similar issue caused airbags to not deploy in front-on accidents.