PCM controlling E-fan on 02 Chevy truck

I have my E-fans set-up to be controlled 100% by the PCM. The fans are working fine with the tempter set points. I can't get the fans to come on high when the the A/C high side pressure get above 200psi set point. I was told that the 02-03 pcm can not control those set-point even know these set-point are in that 02-03yr tune file. I was also told if I get a 04 PCM that it was wired internally able to work those set-points. Can anybody verify this info for me?
Thanks