Post
by X5Sport » Tue Nov 04, 2014 11:47 am
The E53 shouldn't 'drop' a map as that becomes a permanent part of the DDE encoding.
What happens with the newer versions that do go near BMW is that the coding data is known by BMW and leaves a code - sometimes called a checksum - which the systems use to verify the data when the car starts. A remap changes that checksum and next time it's plugged into the BMW servers that change may be noticed and the servers rewrite the data back to what it should be as part of the patching process.
It may only be the 2010+ models that have this.
Wiping the old error codes should be fine as any recurrent ones will be rewritten into the records. Anything that shows up under 'fault present' with a 'No' flag will most likely have been a transient issue.

Never anthropomorphise computers. They hate that.