2012 Prius c PA080 no Inverter Pump Flow

Short version - does the inverter pump in a C behave the the pump in a Gen 2? As in, should I see flow in the coolant reservoir?

Super Long Version - with extra questions...
I have a 2012 Prius C with roughly 155k miles on it.
I also have a 2004 Prius with (est) 350k+ miles on it.

The Prius C is new to us (roughly 6 months).

I recently got the "hybrid system problems - pull over" message with a bunch of lights on the dash.
I wrongly assumed this was a 12V problem because of the lights on the dash.
New 12V does not fix it, if course... lesson learned.

I finally did what I should have done at first and used my DR Prius app to read the codes - only PA080.

Clearing codes is very temporary - error message comes back fairly quickly.

Dr Prius reports Delta SOC > 43%.

I'm guessing my main battery is ready for replacement but...

I checked my inverter coolant tank - no flow and I feel no vibes at the pump when "ready"
No inverter codes.
When the pump went out on my gen 2, we got codes. Also, we had flow after I installed new Toyota pump.

So, I'm confused...

Also, how can I read OBDII sub codes? I also have Torque on my Android phone and loaded a batch of Toyota specific PIDs, but I'm missing sub-codes somehow.

And, finally, any tutorial on replacing the inverter pump? It looks like I can do it without pulling the inverter - maybe pulling the headlight? Does it "bleed" like gen 2?

I feel like these are common questions I should be able to find answers for, but my search skills really suck this weekend for some reason...

I appreciate any help.