1999 Buick Park Avenue - Does drawing one 5v ref low pull the other low?

Hi, I completely removed AC parts from my car, and The stock GM pcm setup uses a 5v ref circuit A for all sensors on the engine, then it has an entire dedicated "circuit B" which is only for the AC pressure sensor which would be mounted in the discharge line off the compressor.  

Since I dont have a sensor in the connector, and the wires are not shorting to anything nearby , I will actually get ghost readings on the scan tool and set a code for AC pressure sensor.  

I dont really care if it does this, but is this in anyway affecting the 5v Ref A circuit?    The car will run fine, but just want to know. I The wiring diagrams, for example, dont indicate they originate in the same place, and they return to separate pins on the PCM.  

Depending on the internal circuitry in the PCM, shorting the 5v ref from that sensor could pull down the other 5v reference circuit, but leaving it disconnected should not effect anything else.

Yes, but do you know if it is infact a separate source? And it being disconnected , what im saying is that it has values which I assume means that that 5v ref is in someway shorting to the sig return. no other 5v wire or even power source come near the wire back to the PCM.

Unplugging a sensor will not necessarily make it value "go away". Unplugging a temp sensor brings the value to -40°f. That doesn't mean the signal wire is shorting to something, that's the open circuit value.
I'm not exactly sure what you mean by " it has a value" or why you think that means the circuits are shorted together. That's easy enough to check with an ohm meter if you really think it's an issue.
As for your 5v ref question, I don't know. That's why I was ambiguous and said "depending on the internal design of the computer".
You can also check this very easily by shorting the 5v ref from the pressure sensor and seeing if it effects any of the other 5v sensors.

I will try explaining this a third time.

The AC pressure sensor, which has a return wire to the PCM and a 5v ref (, while not on the car, doesnt produce a value like a missing resistor. with the sensor on the car, but not on an AC line (atmosphere) it has random values on the scan tool, which would indicate its reading pressure. Without the sensor on it, it actually reads more random values, and it does this from key on not just running. Without a sensor it should have any reading.

I don't get it. Are you trying to fix the air conditioning? I can't tell from reading your posts if there's a sensor hanging by the connector under the hood or if it's just MIA.
A few minutes on the car with a multimeter will tell you if there's crossed circuits on the a/c pressure sensor or if the 5v circuits are shared.
Let us know what you find.

Its not present, and the AC components are also not present. underhood see no evidence that its the wire. I have traced the wires all the way to the PCM , no shorts.

I want to know if the 5v ref B having phantom readings, which presumably is a factor of some internal or otherwise shorting to this signal circuit , will draw or skew the 5v Ref A circuit.

Because the 5v ref A circuit is the important engine sensors that affect how it runs

bgfmars if the car is running fine just tape all ac wires that you are not in use away so they don't short to any thing and your fine good luck