tamrsoft
Active Member
I have to replace the battery on my E220 CDi. Can anyone advise as to whether disconnecting the battery causes any re-synchronisation issues when the new battery is reconnected, ie is any critical ECU data lost that has to be re-entered. I had a similar issue on my old BMW 520 in which ECU parameters were temporarily lost, and it took several miles of driving while they were being re-created (the car drove like a dog). BMW advised maintaining continuity of supply when changing the battery.