Hey everyone! Just picked up a new to me 2001 A4 that I think is a B5 early 2001 and not a B5 mid-gen 2001. Mostly based on the fact it had a two button remote versus a 3 button remote. Trying to further confirm it is to help determine next steps with check engine light that is returning the code - 16989 P0605 Internal Contr.Module ROM Test Error

I pulled the ECU and all the wiring and connectors look pristine. No cracked wires our obviously corroded connections. Is there anything else I should be checking?

If there is nothing else obvious to check, I was thinking of getting a used/tested ECU on eBay and just swapping it out. Based on what I've read here so far, I don't think my car has an immobilizer and hoping I could just drop in the new ECU and not worry about recoding. Thoughts?

Also - any way to determine how many splines my CV axles have without pulling the axles first?

Cheers-
@miggytosh