Car Problem need solution plz

I know this is a nissan group, but ive searched through other forums and no other group is getting "mechanical advice" to their problems. If you know of another group thats gives solutions to common car problems let me know. .but here is the problem I have a 2000 chevy cavalier that has the daytime running lights on during the day. When I put the car out of park the daytime running light (drl) icon on the dashboard flashes and then goes out and the service engine light comes on. The (drl) do not come on during the day anymore and my driver side headlight is too dim compared to the passenger side which is normal. Ive changed both bulbs, changed the (Drl) relay, checked the fuses, inspected the wiring to the headlights and everything seems fine. I've encountered the same problems on the net, with out any solutions. Any solutions might help ..Thanks. Phillip