CEL code 4131 compressor signal

I am getting code 4131 on both the left and right banks of my 95 348. I am able to clear the codes but they come back. I believe the description of this code is "compressor signal", which I assume is related to the AC compressor. I have installed a manual/electric system in place of my factory climate control. I have an electronic thermostat that cycles the compressor through the wire that leads to the factory climate control system. I think this is triggering the code for some reason.

I also have 4121 on that bank, which is for the Cat ECU. Those are the only two codes on that side. My understanding is that 4121 will not illuminate the CEL but my CEL on that side is illuminated all the time. If 4131 is really just an AC compressor signal code would that really count as a "hard code", one that would illuminate the CEL?

BTW the car runs really well.