LS1 PCM and Vintage air?

[EFI69Cam]

Want to integrate 12200411 PCM control of the AC compressor with my vintage air system. The VA system provides ground for the relay coil. Looking at the wiring diagram for a 2002 Corvette it looks like the ac request pin on the PCM is grounded by the ac controller (manual control) however on 2002 camaro schematics it looks like the ac request is switched to +12. Which is correct, or does it depend on the base calibration in the ECM? I'm using Corvette for the ETC.

Don't want to use the trinary switch to control the fans and compressor as the PCM takes additional parameters such as road speed into account for the control algorithm.

[Rhino]

Looking at the schematics I'm seeing the same. I think you're correct that it depends on the OS.

[BBPanel]

See if schematic in here helps:
http://www.ls1tech.com/forums/conversions-hybrids/1177740-vintage-air-gen-iv-ls-pcm-drawing.html

[garys 68]

I think the consensus is that the AC request wont work without the f body pressure switch grafted in.
I'm running VA without any changes to the ecu. Absolutely no problems. I know the ecu twaeks idle speed, but I have not noticed much difference without computer control. And hi rpm compressor cutout doesn't seem to be much of an issue since the compressor pressurizes pretty fast at hi rpm.
I'm using the computer to control 1 fan, based on engine temp. And the trinary and/or engine temp to control the other fan. They're all wired to provide ground to the fan relays.

[EFI69Cam]

Seems like the factory five kit car builders have it figured out in regards to the ac request.

http://www.ffcars.com/forums/showthread.php?t=85929

Corvette calibration looks for a ground on the AC request, which is exactly what the VA controller provides to the relay. So I will remove the VA compressor clutch relay and connect it's trigger wire to the ac request pin on the PCM. The Corvette pressure sensor will be added docsblocks.com has the correct braze on m12 fitting, and the I will wire the compressor just like the Corvette.

Seems to me that the diode on the clutch relay is important to install as it protects the PCM from the back EMF from the compressor clutch since the PCM also monitors the voltage on the switched side of the compressor relay.