Alright my buddy has an '04 9C1 Police Impala that I'm trying to tune for him but my tuner can't seem to pull up his bin file. Do police Impala's have different PCM's or what?

Also would a PCM from an '03 (or older) Impala work and be readable by my tuner? I ask cause his car needs a new BCM and I figured his best route would be to yank both the PCM and BCM out of a car at a junkyard around here, but I didn't know if they would be compatible in an '04 Impala. The motor is a Series II 3.8.