Fitted my newly acquired stage 2 mapped ECU today, it's off my old car which has been broken. I know that the Ross site has a guide on how to sort the immob when swapping ECUs between cars, I tried this one first: Ross-Tech: VAG-COM: Immobilizer 2 ECU Swapping But the car still starts then cuts out, read codes and it showed the 17978 code. Im sure the car is the Immo2 system. my old car was AGU, same as my current, my old one was 97 and this is 99. The old ecu part number is: 06A 906 018 CJ The new (mapped) ecu part number is: 06A 906 018 D Don't think this matters though. I have re-fitted the original ECU, and the car starts fine. Can anyone please help? I am desperate to feel the full potential of the KO3s again! Thanks.