not sure which fuse.i usually disco the negative battery terminal.cant recall if codes will be stored after reboot but if anything is wrong they will comeback of course.ive been trying to get my hands on the official 4matic manual with no luck.but i do have some info on various 4matic issues that i can email

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michael cole 1980 300SD gone now but not forgotten,87tdt,90 300te 4matic 95 e320 wagon