[ziekxq]

Should I remove or at least disconnect power to jb4 while getting ecu/dme software update?

[AZ-MCRacer]

Are you taking it to the dealer or doing a DME update yourself? Are you just flashing a tune, or updating all the firmwares of the car? At a minimum set it to Map 0, then when you flash it will be unplugged from OBD so it won't really be doing anything. When I do my DME flashes for BM3 I don't remove the JB4, I just put it in Map 0 and unplug the OBD connection.

[ziekxq]

Originally Posted by AZ-MCRacer

Are you taking it to the dealer or doing a DME update yourself? Are you just flashing a tune, or updating all the firmwares of the car? At a minimum set it to Map 0, then when you flash it will be unplugged from OBD so it won't really be doing anything. When I do my DME flashes for BM3 I don't remove the JB4, I just put it in Map 0 and unplug the OBD connection.

Im getting it done at the dealer but they know about the mods. Also this is just updating the firmwares of the ecu and probably other modules to the lastest version.