What does it mean
That is a warning of an problem but you will need to have the trouble codes read to know what is going on. Most auto parts stores will read the codes for free.
It could mean a huge variety of things. Almost none of them are scary though so that's nice. You can, as F_O_R mentioned, go to an autoparts store and have them read the codes for you. Or, as I prefer, grab something like the BlueDriver bluetooth OBD2 reader. You can connect this to your phone and get realtime data as well as read/delete codes. Once you have those codes, you'll be able to quickly search for solutions to those common problems.
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