Check Engine Light. on 2005 Hyundai Tucson

I have the Check Engine Light illuminated without any other trouble (I have an automatic gearbox) ; any chance to be a gearbox problem (for instance a broken Hydraulic converter fan)?

Asked by for the 2005 Hyundai Tucson
its possibly a catlytic converter issue, have the cars computered scanned to see what codes are popping up