I went into the service dept. of my dealer ship because my check engine light came on, the guy behind the counter told me that my "aftermarket electronics." were setting of the check engine light he told me that it was my GPS and my alarm. I've had my GPS for two years and its never set of the check engine light and my alarm I’ve had for at least a month of two. My question is can aftermarket electronics from what I know I didn't think it would set if off like that.