A thermal management system for a vehicle propulsion system includes an engine having a coolant inlet and a coolant outlet, a coolant pump having an outlet in communication with the engine coolant inlet, a coolant valve that controls coolant flow from the engine coolant outlet to a transmission heat exchanger, and a coolant valve controller that selectively actuates the coolant valve during an initial transmission warm up condition, wherein the coolant valve controller selectively closes the coolant valve after a transmission temperature exceeds a target transmission temperature.