ok first time user. in my shop iv got this truck it came in cuz of rough idle and once it warmed up it started blowing white smoke and smelled like raw diesel. i went to pull codes on it and and my reader turns on but then says could not connect. i checked fuse number 3(20amp) with a test light and it has power and is not blown and sence the code reader is powering up the dlc has power. can anyone help me with this problem?