Rom code 03 7.3

[cookster155]

hey guys need some help i have a 2003 f350 7.3 stick 4x4 runs like crap check engine lite goes on and off while driving had a friend scan it with a snap on scan tool cam up with a rom error , he said replace pcu ive read that batt disconnect will cause this code ? any suggestion ? how to verify pcu fault? also any suggestions on a replacement used , interchange, plz help thanks
Mark