I have a 2001 S3 Thunderbolt with no spark. I believe it has a bad ECM, altough I am not 100% sure. The ECM #s are BFIUS1 N0306.QA00068 US16KA210.
What is interchangable and what happens if I get one that the N0306.******* number and US1****** number are diffrent then what I have? Is the only option a used one from eBay>
Thank you