PO1 with AC pressure transducer

[rubrhammer]

Is a PO1 PCM capable of controlling the fans through the pressure transducer? Setting is set for 254PSI but isn't turning on the fans.

[2xLS1]

Unless you added a transducer you have a pressure switch.

[rubrhammer]

We have a transducer in the system.

[2xLS1]

Well no one knows what you did with it so good luck figuring it out.

[cobra30689]

Yes it can, and indeed does on F and Y bodies (I own an F-body, so I know first hand lol). It should be wired as such (diagram attached). What I do not know however, is whether the truck OS' (I am assuming that is what you are using??) can "see" the transducer by default.

Screenshot 2025-05-14 225116.png

[Alvin]

I think you either need a late truck OS or a Car OS to do this.

[Fast4.7]

I think you either need a late truck OS or a Car OS to do this.

Agreed. The early truck OS will not correctly run the dual efan setup. I generally use the 2002 O/S as it will run the e-fans correctly and has other changes like knock sensor changes that reduce the tendency to throw false knock.

[abc]

Are you satisfying the pressure requirement?

[rubrhammer]

Are you satisfying the pressure requirement?

Yes. High side reached 275.

[rubrhammer]

Cobra30689. Thank you. I'll go back and check the year that this is. I've used them to control fans via temperature on the early ones but not by pressure.

[rubrhammer]

Fast4.7, thank you.

[rubrhammer]

Alvin, I have both, I'll try that.

[Bigcstyle]

Question I have a 2003 Tahoe that I just put E-fan on. I can command the fans to cut on with hptuners and they work normal but the don?t turn on with the A/C on or go into high speed. I'm using pins 42 in the blue connector and 33 in the green connector with a 3 relay harness off of Amazon. Did I miss something in the tune or do I need to do something else?

[Alvin]

I'm not sure i've seen a ebay/amazon harness work out of the box.

Post the tune file so we can double check your work.