Check Engine Light on a 2007 automtic chevy aveo. it has 39k miles on it.?

well most automitive stores will read ur codes for free and tell u why it is coming on... then u can buy parts to fix it if u want but yes ur tranny is way more important especialy if ur going on a long trip. a cheap fluid change considered to a 2000 transmission replacement?? how u gonna come up with that just cause u wanna fix some stupid light that obviously isnt afffecting your vehicle... i do reccomend getting it read so u no what code it is reading cause sumtimes the code could be important too. so u need to have it read for free just to see if its bad and then ur best bet is do ur tranny fluid change although dealers pricings to fix things sumtimes are hihgher than ur average shop nearby....