I have a 2010 ES with a single CD player. It has a Gracenote database and when I was messing around with it found that it would say Service Mode On/Off. What is this for and what kind of tweaks can I do with it? Not looking to change out radio/CD right now. a Gracenote database and when I was messing around with it found that it would say Service Mode On/Off. What is this for and what kind of tweaks can I do with it? Not looking to change out radio/CD right now. and when I was messing around with it found that it would say Service Mode On/Off. What is this for and what kind of tweaks can I do with it? Not looking to change out radio/CD right now.