Hi all, I am new here. I have a 04 impala LS and I'm having an issue with it. A few months ago my SERVICE VEHICLE SOON light came on and when it does, it kicks all the lights on like it is night time, it does this even during the day. I dont know if my BCM is bad or what. This is not a check engine light. Any help would be appreciated. I have checked and I do not have a headlight out, they are all new.