Hi all,

I have looked at various threads but haven't found an answer, hence this thread>

I have an E38 ECU with a particular OS (12612381) but want to use a different OS due to preference of the various tables (particularly the torque model and flex fuel capability)

How can I effectively change the OS on an E38 ECU?

The way I think best to achieve this would be to download the desired file from AC Delco and flash with Tech 2 which I can do but haven't attempted.
If I do change the OS will the ECU need a new EFILive licence? Is there any other way to achieve the same outcome without bricking the ECU and/or needing to purchase a new licence?

Cheers