check fuel cap light came on 03 gt 5 speed???

well if it helps any about 3 days ago my wife tells me she drove away from the gas pump with the nossle still in the car she realized it 10 feet after she left the gas station, i took a look at the openin but i see no damage what so ever but now 3 days later my check fuel cap light comes on. the nossle came out of the car when she drove away. but she still got out and put the cap on.

thanks for the advice im going to try to disconect my battery cable and i hope it works.