The coolant pump runs on a time cycle and doesn't appear to be temperature based. There's no real rhyme or reason to it running.
There may be some temperature override at some point to run the pump and radiator fan to prevent overheating, but as far as I know, nobody has ever gotten their car hot enough to trigger any such feature.
"Bear" - 2012 Diamond White Pearl ES with QC
"Koorz" - 2012 Cool Silver Metallic ES with QC
"Photon" - 2017 Bolt EV LT in Orange with QC
2018 Tesla Model 3, LR AWD, MSM
Solar-powered since 10/10/2013