Jonathon I feel like I'm being di-k but 57 shows going to IAC and is ground and 45 is 5v reference so is the PIN numbers right or colors you said 57 was power 5 v and 45 was ground
I feel bad asking you to confirm but I don't want to put voltage to ground and vise verse
Thanks again

 

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Thanks so much. The confussing part is 57 shows as being ground not 5 volts and 45 show and being 5v on the fbody wire diagram Your saying connect to 57 5v and I believe 57 is ground

 

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see next post

 

Dan, if you reference this thread:

http://www.norotors.com/index.php?topic=23630.0


And look at his connector, then:

red coloring I put on connector = 5v signal = blue connector pin #45 = gray wire in OE
green coloring I put on connector = ground = red connector pin #57 = purple wire in OE
blue coloring I put on connector = signal = red connector pin #14 = rd/blk wire in OE

 

Johnathon, This was a great write-up with pictures of the color I think my finding today after getting these 3 wires in place as required and I believe I had them wired correct from the beginning as Im getting the 5 volt reference but not getting ground from pcm red pin 57 at pcm This is the iac low reference I tried back pinning and checking for ground I'm just not getting a ground at this pin I'm wondering if there is a low pressure switch that I don't have install on my ls1 swap. It was my understanding this 3 wire switch was high and low. I also tried grounding the wire from the High pressure switch to body ground with no luck. Do you know of anything that triggers red#57 to ground?? Or is there something im missing with applying 12v to the pcm red 17 a/c request signal to activate the replay Is there something special needed from an hvac control assembly beside a 12v signal I believe I'm very close and the problem lies in 1 of these 2 areas. If anyone has in input or suggestions please feel free to sound off. I wish I could throw a large pizza and a 6 pack out there for this missing link?????
Thanks

 

Is your computer flashed with an F body program? My 411 PCM was originally from a truck...and I know the truck fans and stuff are different, and the trucks might use different a/c wiring setup.

So first things first...do you already have an F body program on the pcm?

 

But no there's nothing else that triggers the PCM to engage a/c function. Assuming your pressures are good, once the PCM sees 12v request, it should work

 

How exactly are you testing this? Do you have an ac system fully charged and ready to go and are trying to kick the clutch on, or what exactly are you doing?

 

Yes A/C worked with just 12v and ground direct connect but builds to much pressure so I needed to wire this high preasure switch to be able to control cooling fans raise idle and turn off when pressure builds. Yes pcm is and harness is from 2002 fbody camaro. When I had the original harness built to a stand alone they removed the pins not needed and also the ac pin That was the reason to rewire the High pressure switch.
Right now my relay is wired like in the picture i had attached before. Relay pin 86 and 30 have 12v pin 87 load going to red #18 pcm and compressor The relay is waiting for the ground to 85 to complete the circuit to ground If I jump 85 to ground at relay it kick compressor and relay on so im good there.
As of right now Im not seeing ground at red #57 and when I apply 12v to red #17 nothing happens Im expecting red #43 to ground to 85 on the relay but its not. I dont think at this point its a high pressure switch because all the test I have looked at says test the wires for 5v and ground before replacing the hp switch Im pretty sure my problem lies in the fact Im not getting ground at red#57 diagram says low reference teed into the intake air sensor. Im looking in hp tuners and ac is set on analog ???
My line pressure is at 70 psi right now at rest
Im assuming the purple wire red #57 should be a ground tested with an ohm meter is not ???

 

Just so it's understood how I'm wired and the areas I have question about . Any thoughts anyone

 

http://www.hptuners.com/forum/showthread.php?53376-LS1-AC-not-being-commanded-by-PCM

dan, just for giggles why not try switching the ground and power wire on the sensor?

Seems like doing so won't fry anything, considering the OP on that thread had them backwards from the get go.

And with that said, I have two GM diagrams here that directly contradict each other (the power and ground were reversed). That's why I had so much confusion replying to you immediately.

theres several ls1 related "factory" diagrams that are wrong. I know about a few of them but wasn't aware of these.

If that doesn't help, is your pressure sensor good? Unfortunately I don't have access to my database today since I'm not at work otherwise I could look up a test procedure for the sensor itself.

I see no reason it shouldn't work aside from either bad sensor or wiring reversed.

I'm not experienced enough with HP Tuners to know how the ac should be classified. What are the options other than analog?

 

And as far as I can remember the minimum pressure to activate is somewhere around 22-25lbs, so you should be good there

 

I did try yesterday to reverse the wires no luck I'm wondering if it will get its ground from the sensor back to the red 57 the opposite direction That might make since as that then would send that ground to the iac to activate the rise in idle The only thing I haven't done is replace the hp switch maybe I will just do that and recharge system as I'm 99 percent the hp switch can't be replaced without evac system. Do you know the range of output voltage range should be with sensor operating correctly ??
Johathon are you an admin here if not maybe these wiring question would be better posted in another section I'm not real sure

 

No, I'm not an admin.

But to answer your question you may get more views/help if you start a new thread.

If youre using an LS1 style fitting for your sensor , then it has its own shrader valve and you shouldn't need to evacuate.

Regarding the range, I'm not sure. That's something i can probably look up tomorrow at work in our database. Maybe if you start a new thread today someone will be able to access the info sooner

 

Update !!!!!

You were right after I went back a was writing another post to explain everything I was refferance the picture from the link you sent me to before and notices the gray wire in the picture was on the opisite side as my plug so I switched the wires like you originally suggested and it works but here is the catch The purple wire is not a ground coming from the pcm but if I ground that wire from the plug it works I'm wondering if I need to ground it and pin 57 I'm scared to do that but if you look at the wiring diagram where it goes into pin 57 it also shows up to the right to ground I assumed that meant plug #57 was ground but maybe it also needs to be grounded Im wondering how I could find that info out Any suggestions? Either way I am very close thanks to your help

 

Dan,

any luck on this?

I finally had a couple of free minutes at work. I searched our diagnostic database for testing data for the sensor, but it appears none exists (at least in our database).

I'll copy/paste the information I found on the sensor. This is the ONLY information listed aside from the actual wiring schematics. You already know the gist of this, but I'll post it anyway.


"2002 Chevrolet Camaro 5.7L Eng SS
1Search™
Print Date: 2/21/2017
hvac refrigerant switch/sensor
A/C Pressure Sensor [ A/C COMPRESSOR CLUTCH ]

Some models are equipped with an A/C pressure sensor which is used to inform PCM of A/C system pressure levels. Low pressure signal will cause A/C compressor to disengage to prevent system damage. High pressure levels cause PCM to engage high speed cooling fans while A/C compressor clutch is engaged. Extremely high pressure levels will cause PCM to disengage A/C compressor clutch to prevent system damage.
A/C Pressure Sensor [ INPUT DEVICES ]

Some models are equipped with an air conditioner pressure sensor which is used to inform PCM of A/C system pressure. PCM uses this signal to determine A/C compressor load on the engine to control idle speed with IAC valve. Failure in A/C pressure sensor circuit or with A/C pressure sensor should set a related diagnostic trouble code and A/C compressor clutch will become inoperative. A fixed high pressure value will exist if the ground circuit to sensor is faulty.
A/C Pressure Switches

A/C high and low pressure switches may be used in the PCM-monitored A/C request signal circuit. Switches are normally closed, completing the circuit between ignition and PCM. PCM will engage or disengage A/C clutch relay based upon status of this circuit. When system refrigerant pressure increases beyond a certain point, high side switch will open, causing A/C request line voltage to drop. If system refrigerant level decreases, causing refrigerant pressure to drop below normal, low side pressure switch will open, once again causing A/C request line voltage to drop. Switches may be used as normal clutch cycling devices or as safety devices which prevent compressor damage in the event of excessively high or low refrigerant pressure.
A/C Refrigerant Pressure Sensor

The A/C system is protected by the A/C refrigerant pressure sensor. The sensors output to the PCM is variable and is dependent upon pressure inside the line. A higher pressure results in a higher voltage output. The A/C pressure is constantly monitored in order to allow the A/C compressor clutch to disengage as needed. If line pressures climb above 414 psi (2854 kPa) or fall below 35 psi (241 kPa), the PCM will turn off the A/C compressor clutch. When high side pressures drop back down between 39-250 psi (269-1724 kPa), the PCM will allow the A/C compressor to operate.

A 5 volt reference signal is sent out over the 5 volt reference circuit, from the PCM, to the A/C refrigerant pressure sensor. The PCM reads the A/C pressure by monitoring the voltage on the A/C refrigerant pressure sensor signal circuit. Ground for the A/C refrigerant pressure sensor is provided by the low reference circuit."

 

I think I have it working as supposed to be I think my problem was my gray wire on the plug was on the other side When I went back and looked at your picture I noticed it was on the other side so I swapped the gray and purple Also I did not connect the #57 wire To the purple wire as it didn't have ground so I grounded the purple wire from the high pressure switch and it worked
Thanks again for all your help I hope all this will help someone else