Hi everybody.
Thanks for reading.
Today i had a bad day at the office!
I have E92 335i - MSD 80 - N54 in the workshop with internally faulty DME (internal injector issue but unusually this is not faulty mosfets).
The car runs on three cylinders with original DME.
I managed to find a replacement DME from a 135i - N54. This one is the upgraded MSD81.
When the time came to swap the DME i made two fatal errors!
1. I failed to take a backup of the donor MSD81 before starting (Lets just say this is a mistake i will never make again!)
2. I tried to direct clone the original MSD80 to the donor MSD81 instead of changing ISN / programming / reset working hours.
So the process appeared to go well but after cloning i tried to do backup of MSD81 and realised things had not gone to plan.

When i try to unlock the MSD81 DME i get an error saying 'çannot identify ECU'. If i ignore and continue, i can read flash/EEprom. If the MSD81 is connected to the car I get Fan and coolant pump running full speed. I did not try to start the car but I'm very sure the car would not start. I can still communicate to the MSD81 via OBD but MSD81 identifies itself as MSD80.
I read ISN from MSD81 and ISN has been changed to match the original MSD80.
Hexprog support tried to help / were helpful but basically told me i turned my MSD81 into a paperweight because i failed to take backup of donor. (as i said before, this is on me. Stupid mistake).
Support are probably correct but i wanted to check. Does anybody have other suggestion how to resurrect the MSD81 ?
I would be very grateful. Finding another suitable DME is going to be difficult !

Ok. So not one person makes any comment. I guess the MSD81 is now a door stop.
I was able to find a second MSD81.
MSD80 to 81 swap completed with Autohex. Read /write ISN factory mode. Program and code on car. Write Injector coding. Done.

I have done the same before my friend! Don't feel too bad.

Just an FYI, I would be cautious programming the MSD81, I have done it before many times without issues except for one occurrence and after working with support they recommend when upgrading from MSD80 to MSD81 to only code the MSD81 and not program, it could cause issues when you program.