A/C Pressure Sensor on PCM 411 2002 express van tune

Has anyone ever ran across this situation. I have a 411 PCM with a tune from a 2002 Chevy Express Van . Also I have a Vintage Air A/C system installed in which I wired to use an A/C pressure sensor (22664328) in order for the PCM to control the A/C unit . I changed my AC Type in the tune to analog , The fans and A/C clutch relay comes on when the engine is running, everything appears to work OK except for the A/C pressure Sensor. The fan and A/C clutch relay works whether or not the A/C pressure sensor is installed . Can't figure out why the PCM is not looking for the output from the A/C pressure sensor. The A/C pressure sensor is wired C2-14 red , C2-57 violet , C1-45 gray , A/C clutch relay coil C2-43 and relay contact to C2-18 just like the 2002 Camaro. MY understanding is the PCM should not turn on the fan and A/C clutch relay unless it see the output from the A/C pressure sensor and the engine is running at 550 rpm.

Any help is appreciated.

I think what I found out may help someone with this setup. The 2002 Van tune uses two pressure switches and the OS will not recognize pressure sensors . But that's fine , if you are using the 2002 van tune to run a TPI setup. Wired as I have it and using the van tune the A/C clutch and fan will not engage unless the engine is running above 500 rpm. I think the key to this setup is having C2-18 wired to the relay contact which tell the PCM the A/C clutch is engaged. Without C2-18 neither clutch or fan will engage . My A/C system is a Vintage Air unit which I wanted to signal the PCM 's "AC request " to control the A/C clutch and fan. I just found out it's all in the OS that you use.

Hey I'm using a 411 truck ecm in my 24x conversion. Have you gotten the efans to come on when ac has requested them to through the ecm? I've read once somewhere that you couldn't do it in the truck ecm only the car ones.

i have heard of people getting this to work, but it requires some work, including a segment swap i believe. the easier way to command fans with a/c pressure is to wire up a separate pressure switch and command your relay with it. this is what a lot of folks are doing. I have my 3rd fan wired up to come on with a/c pressure via an additional switch. I just cant turn it off at speed yet.

I have the A/C press sensor and e-fans working in my 96 with a 411 swap, you do have to perform a system segment swap for this to work

im assuming you used an express van for the base tune in your conversion? also what vehicle did you use for the AC segment?

I am looking into something just like this for my 5.3 swapped s10 to try and get better cooling fan controls with the AC on.

2002 Express base tune, I believe the segment swap was from an F-body...you'll need to match OS to perform the swap and adjust pressure parameters accordingly