1 have a 2006 range rover sport 4.2 supercharged need help with ecu problem. I was have problems with the charging system and after doing pin point test on wiring at alternator it showed to be a bad ecm. Long story short I got a known good nnn500411 ecu and took it to local repair shop to install they charged me almost $500 because they had to get the software well they had no success just a big bill and won't start but starts with the old one. So I sent original out to have rebuilt and as no surprise they are now telling me it can't be rebuilt the main board is fried so now they want 800+ to exchange one out and says plug and play. Well since this has been over a month on going I've read alot and it seems these need to be synced to the bcm to communicate. Now my ? Is what do I need to get no ranger rover dealers within 100miles if I use the known good ecu and get the bcm is there anything else I need to get to make this run again keys, immobilizer, cluster be nice to get this going again thanks