It just came on for me on my 2018 Disco (gas engine). I checked the gas cap and filled up the tank with gas, but the light is still on. The car runs/sounds fine. Any thoughts? I have an appt at the dealer for next week for something else, but I will add this to the list.

 

You can go by Oreilly's or Autozone to get the code causing the check engine light unless yours have stopped doing that for Covid reasons. I have heard that some have. Or just visit your dealer.

Bottom line is it can be anything at this point. We would need to at least know "the particular code" causing your check engine light in order the assist.