Patent attributes
A coolant control system of a vehicle includes a coolant pump that pumps coolant to a heat exchanger. A diesel exhaust fluid (DEF) injector injects a DEF into an exhaust system and receives coolant output from the heat exchanger. A fuel heat exchanger transfers heat between coolant and fuel flowing through the fuel heat exchanger. An engine control module is configured to determine a first requested speed for DEF injector cooling, determine a second requested speed for fuel cooling, and based on at least one of the first and second requested speeds, selectively increase at least one of: opening of a valve that controls a flow rate of fuel flowing from the fuel rail to the fuel tank, a flow rate of fuel from fuel injectors of an engine to the fuel tank, and a target speed of the coolant pump.
