I've found some secret codes, e.g: *#*#4636#*#*,*#*#2486#*#*, *#*#372733#*#*. Last one starts an application named "FQC", in this app there is a menu contains "receiver test","led test" etc. I think this is for factory test but after started this test mode, did my device changed to test device? If yes, how can i stop and exit this test mode? Do i need to factory reset?

edit: Device is nokia 6