Electrical glitches after battery replacement?

Hello, okay, by what you are describing and looking through some wiring diagrams, the component in common is this "Driver's MICU" which is a module that's part of the UnderDash Fuse/Relay Box, The OEM diagrams for this year Honda are pretty small, but it looks like that module is the one component that would affect the systems you mentioned here. Pin 16 of the DLC gets power from Fuse 29 but that also branches off in the Drivers MICU in that relay/fuse panel, so it might be that a voltage spike hit the module, that module controls the Door locks through the Lock and Unlock relays which are in turn, Ground controlled by the Drivers MICU. Ill post diagrams of all these,

It looks like scan tool communication is on the K line from the DLC to the Drivers MICU and from there the MICU communicates on the CANBUS to all other modules from there. So, you may try a full system scan if possible. I'm not sure if you lost only communication to the ECM or if it won't communicate with any module at all, but I think I'd stay away from using that power lead feeding into the DLC,
But Ill post some of these diagrams so you can see what you're dealing with here.

These are some pretty crazy OEM diagrams, so it's difficult to tell exactly what might have happened. The Gauge Control Module communicates on the CAN Bus and has one of the 120 Ohm terminating resistors in it.
But it looks like all comms go through this MICU in that fuse panel.
Ill check on any TSBs or Recall info as well

One last thing I see is these vehicles might have an AMG (Absorbent Glass Mat) battery instead of a conventional FLA flooded lead acid battery so the correct one needs to be installed but that is a side note as of now.

On my son's CR-V, also 2014 but FWD, we have just experienced the EXACT same symptoms, and the lead-up to it was also the same. Replaced problematic battery, used an OBDII port memory saver, and now we have the same problem that he described. The same systems he described are dead with the key off, but turn on when the car is running, with the exception of the OBDII port, radio, and center console display - those remain dead even with key on and car running.

So what was the fix for his situation?? I'm guessing we have exactly the same problem, but I'm stumped. I'm not a mechanic, just an experienced DIY car guy. I have a great scan tool, but useless right now since the port is dead.

Hello, I did not hear back from this case as to what the repair was. But I would be cautious about using any device that plugs into the OBD port. If an aftermarket device shorted out pins in the DLC, who knows what kind of issues will show up.
This is the wring diagram and fuse for the DLC power on pin 16. Start with checking the fuse with a test light.

https://2carpros.com/articles/how-to-use-a-test-light-circuit-tester/

Thank you SO much for the reply, and for spelling it out clearly. Reading and interpreting wiring diagrams properly is one of my weakest skills.

It ended up being exactly what you pointed me to: [Under-hood fuse box — fuse No. 29, BACK UP, 10 A]. It was blown. Once replaced everything is back to life and back to normal, thank God.

And point well taken regarding the OBD port memory saver device. It's going straight in the trash. Reprogramming a few radio stations doesn't seem like such an inconvenience anymore after the headache I just went through on this!

Many of them will cause a draw on the battery as well when the vehicle is off. I have seen them cause issues on the data networks as well, because the vehicle's electrical system is just not designed to have devices running on the DLC that are doing "who knows what" half the time. Glad thats all it was.