Hi I need help , I have damage ecu in BMW X5 3.0
Old ecu is starting the car but loss of power, I bought
2nd hand ecu with same part number , then read ecu isn
It manage to retrieve the Sk and isn from ecu (new donour ecu)
Then went to cas to write isn in cas , auto hex says writing done
But car just cranks no start, when I check isn in cas it did change
But no start cannot see live data or anything just get a ecu rejected message
Any help