2000 cavalier check engine light

My car has 48, 000 miles (I know that it very low). My check engine light came on this morning while driving to work. It had happened one other time when I had filled up with gas. That is not the situation at this time. My trunk yesterday was not closing properly and had to be adjusted by moving the screws so it would close. Since it is always used with my automatic button and not with the key itself, do you think that this could be the cause since it is electrical also? My car when stopped at a light did not act any differently, idle or other idiot light-wise, so I am stumped.