A fluid pump (10) includes a pumping chamber (14), an inlet (16) and an outlet (18) fluidly connected with the pumping chamber, and a passage (24) fluidly connected between the inlet and the outlet. Fluid flowing through the passage bypasses the pumping chamber. In one example, the fluid pump (10) pumps coolant within a vehicle cooling system between a heater core (23b) and a vehicle engine (23a).