https://www.cnet.com/roadshow/news/hyundai-2013-veloster-recall-engine-software-fires/

The problem stems from the engine management software. In the affected vehicles, the software might cause the air-fuel mixture in the cylinder to ignite at the wrong time. This can lead to increased cylinder pressures that have the potential to damage the engine, leading to a vehicle stall or possibly even a fire. Drivers might hear a knocking noise and see a warning light illuminate in the gauge cluster.

Hyundai discovered this flaw after NHTSA's Office of Defects Investigation claimed to find a trend in stalls and noncollision fires in certain Veloster vehicles. Hyundai checked all its data and found that claims for stalls and noncollision fires dropped significantly starting in the 2014 model year. After diving deeper, Hyundai concluded that software from the 2013 model year was causing these issues. Thankfully, there are no reports of accidents or injuries related to this flaw.