Mike, you describe a "rear cooling pump" but there is no coolant pump in the battery area. The only thing going to the HV battery for cooling is AC refrigerant, which as you probably know doesn't require any pump except for the compressor (which is up front of course).

I think the pump in question is in the motor/electronics coolant loop which is all contained under the hood.

See section 307-02B, "Transaxle/Transmission Cooling -- Escape Hybrid" item number 4 in the diagram.