There's rising suspicion in South Korea that a spate of car fires affecting BMW sedans is actually down to a software problem, not a hardware issue as the German automaker has claimed. 

The Korea Consumer Association gave its assessment during a press conference in Seoul on Tuesday, calling on the government to look into its claims. It also urged BMW to provide an explanation. 

The association said it conducted experiments on two BMW vehicles not subject to the recall and four BMW cars that are. It found that, while the engine was running, the first vehicles' bypass valves were closed, but the same valves were open in the ones subject to recall. 
 
They claim BMW designed the electronic control unit of the problematic cars in a way that their bypass valve remains open while the engine is on in order to reduce emissions. 

BMW argues the cars caught fire due to a defective exhaust gas recirculation(EGR) module and cooler.