Will CAN partially work if not wired correctly?

Trying to determine if the issue I'm having getting Load/MAP via CAN from my Hondata to my Plex Knock Monitor is related to settings or wiring. Currently the Plex is successfully getting RPM from CAN but not Load. My assumption is that if the wiring or resistors were wrong it would get neither, and that since it is at least getting RPM then the wiring and resistor situation should at least be correct?

There were only 2 wires to connect up, CAN-H & CAN-L. The Plex has a resistor built-in. I've simply wired CAN-H from the Plex directly to the same on the Hondata and likewise for CAN-L. Both ends of the connectors have been checked for continuity (at the actual terminating connectors post-crimp).

There doesn't seem to be a CAN-Ground connection coming off the Plex though on the Hondata circuit board where you hook up your digital inputs it does have a pin available for Ground which is currently hooked up to nothing.

hello if the wiring not correct it will not work at all it sems more likely there is a data stream issue