Trying to adapt a used ecm from the junkyard to my 2000 mk4 golf gls tdi Immo-2. Doing this to minimize downtime while I send off my current ecu to get tuned. Both part numbers are exactly the same except one is German (original) and the secondhand one I bought From the junkyard says Brazil on the metal housing. I was only able to communicate with my ecu a handfull of times before I just kept getting communication errors. On the used ecu I followed the instructions on the Immo 2 instructions and I couldn’t get it to start the car, then it wouldn’t connect at all. I tried two different computers same result. Also of note is I’ve bought a used cluster off eBay as well because I ruined my old cluster with a botched soldiering job where I tore off a pad to the check engine light led, which was probably just fine. but I’ve been chasing this no check engine light on key on down a long and deep bunny hole it’s driving me nuts I’ve got about 50 days until the smog is due. looking for guidance