Aux coolant pump no workie

[AV8R4AA]

My Schwaben code reader detected a inoperative aux coolant pump.
I think it died. My question is what does it do?
From what I understand, it helps coolant circulate at extended
idle. Like waiting for a train..

Not a lot of calling for extra heat at the epicenter of the heat belt.
My Mercedes’ SUV had a Aux pump that continued to run after shutdown.

I thought that was important, so replaced that one.

Any intel on the V8 X5 aux pump.
Can I live without it?