The Nationwide Freeway Site visitors Security Administration (NHTSA) has stepped up its probe into engine fires which have plagued some Hyundai Motor Co and Kia Motors Corp autos for greater than six years.

The U.S. auto security company mentioned it had opened an “engineering evaluation” protecting about 3 million autos to guage, amongst different issues, the efficacy of remembers initiated by the 2 automakers. The company added that it was conscious of 161 fires occurring doubtlessly attributable to engine failures.

An engineering evaluation is the following step in a course of that might result in a recall, though typically NHTSA closes such probes with out requiring any motion.

The company had opened an investigation in 2019 protecting the 2011-2014 Kia Optima and Sorento and the 2010-2015 Kia Soul, together with the 2011-2014 Hyundai Sonata and Santa Fe to analyze cases of non-crash fires.

Hyundai mentioned on Monday it continues to completely cooperate with NHTSA with reference to non-collision engine fires. Kia didn’t reply to a request for remark.

The 2 South Korean firms had agreed to a file $210 million civil penalty final 12 months after regulators mentioned they did not recall 1.6 million autos for engine points in a well timed vogue.