Purchased an Xcalibrator 2 from Alternative Auto. When I attempted to program with their tune, I got an "ECM Unlock Fail". How does one unlock the ECM. I searched this website, no mention of it (or I missed it). What gives?
Also, what's the story on the fuse pulling exercise? Are we worried about current draw on the 12v battery or some spurius voltage spike generated from an inductive device (fan, motor)when it turns on? To pull or not to pull...?