The ccm drives the digital display on the dash, so it is likely to not work when you pull the fuse.
I suggest you make an idle traffic log with obd1 pcm and with the obd2 pcm and post it. I will see...

Well it could be that the ccm use different address or gm somehow switched something on the aldl line communication.
On the eehack`s main window there is a tab called raw. You can do an idle traffic...

You need to load a calibration from 1995 on the PCM for the transmission.
You sure you get code 96. Cant you just grab a knock sensor from 94-95 application and scrap that resistor mod.
Make sure...