If the update does not include a new bootloader, the unlock remains active.
Otherwise, a new unlock will be required. In this case, it is recommended to advise the end customer not to perform updates at the dealership, especially if the vehicle is no longer covered by the manufacturer’s warranty.
If an ECU update removes the Unlock, for BMW ECUs there is no need to send the ECU again. You simply need to apply the bench-protocol OBD Unlock Patch using an AutoTuner tool.
NO NEED TO SEND THE ECU AGAIN FOR A NEW UNLOCK ON BMW ECUs