Ac 530 code

I have a 2000 Silverado 6.0 4l80e and it keeps throwing the 530 code which is high pressure on the ac which disables the ac. I have replaced every pressure switch ,checked wiring with voltmeter, changed orfice tube, I can command the ac with hptuners and it will work.Attachment 48459 Attachment 48459 I saw this on another site and wondering if this is my problem since this is not the original computer. Here is my file if anyone wants to take a look or knows a fix for this. Thanks Craig Attachment 48460